阅读说明：本技术 一种盲元检测方法、装置及电子设备 (Blind pixel detection method and device and electronic equipment ) 是由 马甲迎 唐杰 谢浩山 于 2018-05-29 设计创作，主要内容包括：本申请实施例提供了一种盲元检测方法、装置及电子设备。该方法包括：获得关于辅助对象的多帧目标图像；其中,任一帧目标图像为：在一预定环境温度下,红外热成像设备中的红外焦平面阵列所感应的关于所述辅助对象的图像,且不同帧目标图像对应不同的预定环境温度；计算所述多帧目标图像对应的至少一帧差值图像,其中,任一帧差值图像为将两帧目标图像作差所得的图像；针对每一帧差值图像,基于该差值图像和所述红外焦平面阵列中各个像元对应的关于该差值图像的像素值,确定所述红外焦平面阵列中的盲元。通过本方案,可以快速有效地检测红外焦平面阵列在不同温度环境下所表现出的盲元。(The embodiment of the application provides a blind pixel detection method, a blind pixel detection device and electronic equipment. The method comprises the following steps: obtaining a plurality of frames of target images about the auxiliary object; wherein, any frame of target image is: under a preset environment temperature, images which are induced by an infrared focal plane array in the infrared thermal imaging equipment and are related to the auxiliary object, and different frames of target images correspond to different preset environment temperatures; calculating at least one frame of difference image corresponding to the multiple frames of target images, wherein any frame of difference image is an image obtained by subtracting two frames of target images; and for each frame of difference image, determining blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to each pixel element in the infrared focal plane array and related to the difference image. Through the scheme, the blind pixels of the infrared focal plane array under different temperature environments can be quickly and effectively detected.)

1. A blind pixel detection method is characterized by comprising the following steps:

obtaining a plurality of frames of target images about the auxiliary object; wherein, any frame of target image is: under a preset environment temperature, images which are induced by an infrared focal plane array in the infrared thermal imaging equipment and are related to the auxiliary object, and different frames of target images correspond to different preset environment temperatures;

calculating at least one frame of difference image corresponding to the multiple frames of target images, wherein any frame of difference image is an image obtained by subtracting two frames of target images;

And for each frame of difference image, determining blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to each pixel element in the infrared focal plane array and related to the difference image.

2. The method according to claim 1, wherein the plurality of predetermined ambient temperatures corresponding to the plurality of frames of target images belong to at least two temperature zones, and each temperature zone comprises at least two predetermined ambient temperatures; under different temperature zones, the target equipment parameters of the infrared thermal imaging equipment are different;

The step of calculating at least one frame of difference image corresponding to the multiple frames of target images includes:

and calculating a difference image corresponding to each group of target images aiming at each group of target images, wherein the preset environmental temperature corresponding to any group of target images belongs to the same temperature zone.

3. the method according to claim 2, wherein the step of obtaining a plurality of frames of target images about auxiliary objects comprises:

sequentially obtaining multi-frame target images related to the auxiliary objects according to the ascending order or the descending order of the corresponding preset environmental temperatures;

the step of calculating the difference image corresponding to each group of target images comprises:

and for each group of target images, after the target image is obtained for the second time, the currently obtained target image is differenced with the last obtained target image to obtain a difference image, and the last obtained target image is deleted.

4. The method according to claim 2, wherein the step of determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values corresponding to the respective pixel elements in the infrared focal plane array and related to the difference image is performed for each frame of difference image, and the method further comprises:

and acquiring a gain matrix matched with the difference image for each frame of difference image, and performing data amplification processing on the difference image by using the acquired gain matrix.

5. the method of claim 4, wherein the step of obtaining the gain matrix matched to the difference image comprises:

determining target reference information, wherein the target reference information is as follows: acquiring a target device parameter utilized in a first image or a temperature partition to which a preset environment temperature corresponding to the first image belongs, wherein the first image is a target image for generating the difference image;

and determining a target gain matrix corresponding to the target reference information based on the corresponding relation between the preset reference information and the gain matrix, and taking the target gain matrix as a gain matrix matched with the difference image.

6. the method of claim 5, wherein the determining the gain matrix corresponding to any reference information comprises:

obtaining a first image about a first object and a second image about a second object, wherein the first image is: an image of the first object sensed by the infrared focal plane array at a first temperature; the second image is: an image of the second object sensed by the infrared focal plane array at a first temperature; the temperature of the first object is lower than the first temperature, the temperature of the second object is higher than the first temperature, and the first temperature is the temperature in the temperature partition corresponding to the current reference information;

according to a preset calculation mode, calculating a gain value corresponding to each pixel in the infrared focal plane array to obtain a gain matrix;

the predetermined calculation method comprises the following steps:

determining a first difference value of the pixel mean value of the second image and the pixel mean value of the first image;

Calculating a second difference value between the pixel value of the second image and the pixel value of the first image corresponding to the pixel;

and taking the ratio of the first difference value to the second difference value as a gain value corresponding to the pixel.

7. The method according to any of claims 1 to 6, wherein the step of determining, for each frame of the difference image, the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to the respective pixel elements in the infrared focal plane array comprises:

Calculating a global mean and a global standard deviation of the difference image for each frame of difference image;

And aiming at each pixel element in the infrared focal plane array, calculating a third difference value of the pixel value of the difference image corresponding to the pixel element and the global mean value, judging whether the third difference value is greater than a first preset multiple of the global standard deviation, and if so, determining that the pixel element is a blind pixel.

8. the method according to any of claims 1 to 6, wherein the step of determining, for each frame of the difference image, the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to the respective pixel elements in the infrared focal plane array comprises:

for each frame of difference image, calculating the mean value and the standard deviation of the difference image in a partition mode to obtain the local mean value and the local standard deviation of the difference image;

calculating a fourth difference value of a pixel value of the difference image corresponding to each pixel element in the infrared focal plane array and a target local mean value, judging whether the fourth difference value is larger than a second preset multiple of a target local standard deviation or not, and if so, determining that the pixel element is a blind pixel;

wherein the target local mean is: the corresponding difference image area comprises a local mean value of the pixel value corresponding to the pixel; the target local standard deviation is: the corresponding difference image area contains the local standard deviation of the pixel value corresponding to the pixel element.

9. A blind pixel detection apparatus, comprising:

a target image obtaining unit for obtaining a plurality of frames of target images about the auxiliary object; wherein, any frame of target image is: under a preset environment temperature, images which are induced by an infrared focal plane array in the infrared thermal imaging equipment and are related to the auxiliary object, and different frames of target images correspond to different preset environment temperatures;

the difference image calculating unit is used for calculating at least one frame of difference image corresponding to the multiple frames of target images, wherein any frame of difference image is an image obtained by subtracting two frames of target images; and the blind pixel determining unit is used for determining the blind pixels in the infrared focal plane array according to each frame of difference image and the pixel values of the difference image corresponding to each pixel element in the infrared focal plane array.

10. an electronic device is characterized by comprising a processor, a communication interface, a memory and a communication bus, wherein the processor and the communication interface are used for realizing mutual communication by the memory through the communication bus;

a memory for storing a computer program;

A processor for implementing the method steps of any of claims 1 to 8 when executing a program stored in the memory.

Technical Field

The present application relates to the field of infrared thermal imaging technologies, and in particular, to a blind pixel detection method and apparatus, and an electronic device.

background

the infrared focal plane array in the infrared thermal imaging device inevitably has the problems of blind pixels, non-uniformity and the like under the influence of factors such as manufacturing process, materials and the like. Because the existence of the blind pixels can affect the image processing algorithm and the visual effect in the later period, the blind pixels in the infrared focal plane array need to be detected, and therefore blind pixel removing processing is performed subsequently. The blind pixels comprise dead pixels and overheated pixels, the dead pixels are pixels with response rate lower than the average response rate of 1/10, and the overheated pixels are pixels with response rate 10 times higher than the average response rate according to the regulations in the national standard GB/T17444-1998.

in addition, for the infrared focal plane array without temperature control, the change of the response rate of the pixels under different environmental temperatures has great influence on the blind pixels, namely, the response rate of the pixels in a normal range under one environmental temperature is changed into the response rate in an abnormal range under other environmental temperatures, and the pixels become new blind pixels.

therefore, how to rapidly and effectively detect the blind pixels of the infrared focal plane array in different temperature environments is an urgent problem to be solved.

Disclosure of Invention

An object of the embodiments of the present application is to provide a method and an apparatus for detecting blind pixels, and an electronic device, so as to quickly and effectively detect the blind pixels of an infrared focal plane array in different temperature environments. The specific technical scheme is as follows:

in a first aspect, an embodiment of the present application provides a blind pixel detection method, including:

Obtaining a plurality of frames of target images about the auxiliary object; wherein, any frame of target image is: under a preset environment temperature, images which are induced by an infrared focal plane array in the infrared thermal imaging equipment and are related to the auxiliary object, and different frames of target images correspond to different preset environment temperatures;

calculating at least one frame of difference image corresponding to the multiple frames of target images, wherein any frame of difference image is an image obtained by subtracting two frames of target images;

and for each frame of difference image, determining blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to each pixel element in the infrared focal plane array and related to the difference image.

Optionally, a plurality of predetermined ambient temperatures corresponding to the multi-frame target images belong to at least two temperature zones, and each temperature zone includes at least two predetermined ambient temperatures; under different temperature zones, the target equipment parameters of the infrared thermal imaging equipment are different;

The step of calculating at least one frame of difference image corresponding to the multiple frames of target images includes:

And calculating a difference image corresponding to each group of target images aiming at each group of target images, wherein the preset environmental temperature corresponding to any group of target images belongs to the same temperature zone.

Optionally, the step of obtaining multiple frames of target images related to the auxiliary object includes:

sequentially obtaining multi-frame target images related to the auxiliary objects according to the ascending order or the descending order of the corresponding preset environmental temperatures;

the step of calculating the difference image corresponding to each group of target images comprises:

and for each group of target images, after the target image is obtained for the second time, the currently obtained target image is differenced with the last obtained target image to obtain a difference image, and the last obtained target image is deleted.

Optionally, before the step of determining, for each frame of difference image, a blind pixel in the infrared focal plane array based on the difference image and a pixel value corresponding to each pixel element in the infrared focal plane array and related to the difference image, the method further includes:

And acquiring a gain matrix matched with the difference image for each frame of difference image, and performing data amplification processing on the difference image by using the acquired gain matrix.

optionally, the step of obtaining a gain matrix matched to the difference image includes:

determining target reference information, wherein the target reference information is as follows: acquiring a target device parameter utilized in a first image or a temperature partition to which a preset environment temperature corresponding to the first image belongs, wherein the first image is a target image for generating the difference image;

And determining a target gain matrix corresponding to the target reference information based on the corresponding relation between the preset reference information and the gain matrix, and taking the target gain matrix as a gain matrix matched with the difference image.

Optionally, the determining manner of the gain matrix corresponding to any reference information includes:

obtaining a first image about a first object and a second image about a second object, wherein the first image is: an image of the first object sensed by the infrared focal plane array at a first temperature; the second image is: an image of the second object sensed by the infrared focal plane array at a first temperature; the temperature of the first object is lower than the first temperature, the temperature of the second object is higher than the first temperature, and the first temperature is the temperature in the temperature partition corresponding to the current reference information;

According to a preset calculation mode, calculating a gain value corresponding to each pixel in the infrared focal plane array to obtain a gain matrix;

the predetermined calculation method comprises the following steps:

determining a first difference value of the pixel mean value of the second image and the pixel mean value of the first image;

Calculating a second difference value between the pixel value of the second image and the pixel value of the first image corresponding to the pixel;

and taking the ratio of the first difference value to the second difference value as a gain value corresponding to the pixel.

Optionally, the step of determining, for each frame of difference image, a blind pixel in the infrared focal plane array based on the difference image and a pixel value of the difference image corresponding to each pixel element in the infrared focal plane array includes:

calculating a global mean and a global standard deviation of the difference image for each frame of difference image;

and aiming at each pixel element in the infrared focal plane array, calculating a third difference value of the pixel value of the difference image corresponding to the pixel element and the global mean value, judging whether the third difference value is greater than a first preset multiple of the global standard deviation, and if so, determining that the pixel element is a blind pixel.

Optionally, the step of determining, for each frame of difference image, a blind pixel in the infrared focal plane array based on the difference image and a pixel value of the difference image corresponding to each pixel element in the infrared focal plane array includes:

for each frame of difference image, calculating the mean value and the standard deviation of the difference image in a partition mode to obtain the local mean value and the local standard deviation of the difference image;

Calculating a fourth difference value of a pixel value of the difference image corresponding to each pixel element in the infrared focal plane array and a target local mean value, judging whether the fourth difference value is larger than a second preset multiple of a target local standard deviation or not, and if so, determining that the pixel element is a blind pixel;

Wherein the target local mean is: the corresponding difference image area comprises a local mean value of the pixel value corresponding to the pixel;

the target local standard deviation is: the corresponding difference image area contains the local standard deviation of the pixel value corresponding to the pixel element.

in a second aspect, an embodiment of the present application provides a blind pixel detection apparatus, including:

A target image obtaining unit for obtaining a plurality of frames of target images about the auxiliary object; wherein, any frame of target image is: under a preset environment temperature, images which are induced by an infrared focal plane array in the infrared thermal imaging equipment and are related to the auxiliary object, and different frames of target images correspond to different preset environment temperatures;

the difference image calculating unit is used for calculating at least one frame of difference image corresponding to the multiple frames of target images, wherein any frame of difference image is an image obtained by subtracting two frames of target images; and the blind pixel determining unit is used for determining the blind pixels in the infrared focal plane array according to each frame of difference image and the pixel values of the difference image corresponding to each pixel element in the infrared focal plane array.

optionally, a plurality of predetermined ambient temperatures corresponding to the multi-frame target images belong to at least two temperature zones, and each temperature zone includes at least two predetermined ambient temperatures; under different temperature zones, the target equipment parameters of the infrared thermal imaging equipment are different;

The difference image calculation unit includes:

And the difference image calculation subunit is used for calculating a difference image corresponding to each group of target images, wherein the preset environmental temperature corresponding to any group of target images belongs to the same temperature partition.

Optionally, the target image obtaining unit is specifically configured to:

sequentially obtaining multi-frame target images related to the auxiliary objects according to the ascending order or the descending order of the corresponding preset environmental temperatures;

The difference image calculation subunit is specifically configured to:

And for each group of target images, after the target image is obtained for the second time, the currently obtained target image is differenced with the last obtained target image to obtain a difference image, and the last obtained target image is deleted.

Optionally, the blind pixel detection apparatus further includes:

and the gain unit is used for acquiring a gain matrix matched with the difference image for each frame of difference image and performing data amplification processing on the difference image by using the acquired gain matrix before the step of determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to the pixel elements in the infrared focal plane array by the blind pixel determination unit.

optionally, the obtaining, by the gain unit, a gain matrix matched with the difference image specifically includes:

determining target reference information, wherein the target reference information is as follows: acquiring a target device parameter utilized in a first image or a temperature partition to which a preset environment temperature corresponding to the first image belongs, wherein the first image is a target image for generating the difference image;

and determining a target gain matrix corresponding to the target reference information based on the corresponding relation between the preset reference information and the gain matrix, and taking the target gain matrix as a gain matrix matched with the difference image.

Optionally, the determining manner of the gain matrix corresponding to any reference information includes:

obtaining a first image about a first object and a second image about a second object, wherein the first image is: an image of the first object sensed by the infrared focal plane array at a first temperature; the second image is: an image of the second object sensed by the infrared focal plane array at a first temperature; the temperature of the first object is lower than the first temperature, the temperature of the second object is higher than the first temperature, and the first temperature is the temperature in the temperature partition corresponding to the current reference information;

According to a preset calculation mode, calculating a gain value corresponding to each pixel in the infrared focal plane array to obtain a gain matrix;

The predetermined calculation method comprises the following steps:

determining a first difference value of the pixel mean value of the second image and the pixel mean value of the first image;

calculating a second difference value between the pixel value of the second image and the pixel value of the first image corresponding to the pixel;

and taking the ratio of the first difference value to the second difference value as a gain value corresponding to the pixel.

optionally, the blind pixel determination unit includes a first determination unit;

The first determination unit is configured to:

calculating a global mean and a global standard deviation of the difference image for each frame of difference image;

And aiming at each pixel element in the infrared focal plane array, calculating a third difference value of the pixel value of the difference image corresponding to the pixel element and the global mean value, judging whether the third difference value is greater than a first preset multiple of the global standard deviation, and if so, determining that the pixel element is a blind pixel.

optionally, the blind pixel determination unit includes a second determination unit;

the second determination unit is configured to:

for each frame of difference image, calculating the mean value and the standard deviation of the difference image in a partition mode to obtain the local mean value and the local standard deviation of the difference image;

Calculating a fourth difference value of a pixel value of the difference image corresponding to each pixel element in the infrared focal plane array and a target local mean value, judging whether the fourth difference value is larger than a second preset multiple of a target local standard deviation or not, and if so, determining that the pixel element is a blind pixel;

wherein the target local mean is: the corresponding difference image area comprises a local mean value of the pixel value corresponding to the pixel;

The target local standard deviation is: the corresponding difference image area contains the local standard deviation of the pixel value corresponding to the pixel element.

in a third aspect, an embodiment of the present application provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, where the processor and the communication interface complete communication between the memory and the processor through the communication bus;

a memory for storing a computer program;

the processor is configured to implement the steps of the blind pixel detection method provided in the embodiment of the present application when executing the program stored in the memory.

In the embodiment of the application, multi-frame target images related to auxiliary objects are obtained; wherein, any frame of target image is: under a preset environment temperature, sensing an image related to the auxiliary object by an infrared focal plane array in the infrared thermal imaging equipment, wherein different frames of target images correspond to different preset environment temperatures; calculating at least one frame of difference image corresponding to the multiple frames of target images, wherein any frame of difference image is an image obtained by subtracting two frames of target images; and determining blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to the pixel elements in the infrared focal plane array and related to the difference image for each frame of difference image. In the scheme, the blind pixels in the infrared focal plane array are determined based on the difference relationship of the pixel data sensed by the pixels in the infrared focal plane array at different preset environmental temperatures, so that the blind pixels of the infrared focal plane array in different temperature environments can be quickly and effectively detected.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

fig. 1 is a flowchart of a blind pixel detection method according to an embodiment of the present disclosure;

fig. 2 is another flowchart of a blind pixel detection method according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a blind pixel detection apparatus according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In order to quickly and effectively detect blind pixels of an infrared focal plane array in different temperature environments, the embodiment of the application provides a blind pixel detection method, a blind pixel detection device and electronic equipment.

First, a blind pixel detection method provided in an embodiment of the present application is described below.

It should be noted that an execution subject of the blind pixel detection method provided in the embodiments of the present application may be a blind pixel detection apparatus. In a specific application, the blind pixel detection device can be operated in an infrared thermal imaging device with an infrared focal plane array, and of course, can also be operated in an electronic device which is communicated with the infrared thermal imaging device. The infrared thermal imaging equipment can be an infrared focal plane detector, an infrared thermal imaging engine core assembly, an infrared thermal imager and the like, wherein the type of the infrared thermal imager comprises but is not limited to a temperature measurement type, an observation type and a vehicle-mounted type; it is reasonable that the electronic device may be a terminal device or a server.

it is understood that the infrared Focal Plane Array (infrared Focal Plane Array) belongs to the Focal Plane of the infrared optical system, and a multi-element planar Array infrared detection element corresponding to one sensitive element can be arranged on each image element of a scene in the whole view field.

As shown in fig. 1, a method for detecting a blind pixel provided in an embodiment of the present application may include the following steps:

s101, obtaining multi-frame target images of auxiliary objects;

Wherein, any frame of target image is: under a preset environment temperature, the infrared focal plane array in the infrared thermal imaging device senses images related to the auxiliary object, and different frame target images correspond to different preset environment temperatures.

in order to detect the blind pixels, the optical path of the infrared thermal imaging device can be shielded by an auxiliary object, so that the infrared focal plane array of the infrared thermal imaging device can sense the auxiliary object, and a target image of the auxiliary object is generated; and, the ambient temperature in which the infrared thermal imaging apparatus is located may be adjusted in accordance with a plurality of predetermined ambient temperatures. In this way, the blind pixel detection device can obtain a plurality of frames of target images about the auxiliary object, and further perform the subsequent processing. It is to be understood that in a particular application, any target image may be a frame of image generated by the infrared thermal imaging device; of course, any target image may also be a result of performing mean filtering on multiple frames of images generated by the infrared thermal imaging apparatus, where the multiple frames of images correspond to the same predetermined ambient temperature.

wherein the auxiliary object may be an object with uniform radiation properties, such as: and (4) a uniform radiation surface. Also, in order to ensure uniform radiation, the auxiliary object may be an object made of only one material, but is not limited thereto. In addition, the auxiliary object can be fixed manually or through a specific fixing device, so that the auxiliary object can stably shield the optical path of the infrared thermal imaging device.

Wherein the plurality of predetermined ambient temperatures may be: the temperature in the working temperature range of the infrared focal plane array is not limited by the specific temperature values of a plurality of preset environment temperatures. In a specific application, the blind pixel detection device can obtain multiple frames of target images together; of course, multiple frames of target images about the auxiliary object may also be obtained in sequence, for example: the multiple frames of target images about the auxiliary object may be sequentially obtained in descending or ascending order of the corresponding predetermined environmental temperatures.

S102, calculating at least one frame of difference image corresponding to the multiple frames of target images, wherein any frame of difference image is an image obtained by subtracting two frames of target images;

In order to quickly and effectively detect the blind pixels of the infrared focal plane array in different temperature environments, the scheme provided by the embodiment of the application uses the difference relationship of the pixel data sensed by the pixels in the infrared focal plane array at different preset environmental temperatures as the basis for judging whether the pixels are blind or not. Therefore, the blind pixel detection device can calculate at least one frame of difference image corresponding to a plurality of frames of target images, and further perform subsequent processing by using the at least one frame of difference image.

the blind pixel detection device may perform difference processing on any two obtained target images, or perform difference processing on two successively obtained target images, which is reasonable. The difference image is obtained by subtracting two frames of target images, so that each pixel value in the difference image is a pixel difference value of the two frames of target images, and each pixel element in the infrared focal plane array has a corresponding pixel value in the difference image.

Optionally, when multiple frames of target images are obtained in sequence, in order to reduce the storage space occupancy rate, the step of calculating at least one difference image corresponding to the multiple frames of target images may include:

after the target image is obtained each time from the second time, the current obtained target image is differed from the last obtained target image to obtain a difference image, and the last obtained target image is deleted.

in addition, it is understood that, after the target image is obtained, the blind pixel detection apparatus may calculate the difference image directly using the obtained target image. Of course, since noise usually exists in the target image, in order to further improve the blind pixel detection accuracy, after the target image is obtained, the blind pixel detection apparatus may perform denoising processing on the obtained target image, and calculate a difference image based on the denoised target image. The denoising process may include, but is not limited to, mean filtering, median filtering, K-nearest neighbor smoothing filtering, symmetric nearest neighbor mean filtering, and the like.

s103, for each frame of difference image, determining blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to the difference image in each pixel of the infrared focal plane array.

the blind pixel detection device has the same processing procedure for each frame of difference image. Specifically, the processing procedure may include: and determining blind pixels in the infrared focal plane array based on the difference image and the pixel values corresponding to the pixel elements in the infrared focal plane array and related to the difference image. After all difference images are processed, the blind pixel detection device can quickly and effectively detect the blind pixels of the infrared focal plane array in different temperature environments.

in addition, for convenience of calculation, for each frame of difference image, before the step of determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to the pixels in the infrared focal plane array, each difference image may be subjected to data amplification by using a preset gain matrix. All difference images may correspond to the same gain matrix, and the preset gain matrix may be set according to an empirical value, which is not limited in the present application.

it should be noted that, for each frame of difference image, there are various specific implementation manners for determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to each pixel element in the infrared focal plane array, and the following description is given by combining the two specific implementation manners.

Optionally, in an implementation manner, the step of determining, for each frame of difference image, a blind pixel in the infrared focal plane array based on the difference image and a pixel value corresponding to each pixel element and related to the difference image includes:

Calculating a global mean and a global standard deviation of the difference image for each frame of difference image;

And calculating a third difference value of the pixel value of the difference image corresponding to each pixel in the infrared focal plane array and the global mean value, judging whether the third difference value is greater than a first preset multiple of the global standard deviation, and if so, determining that the pixel is a blind pixel. The first predetermined multiple may be 2 times, 3 times, 4 times, and the like, which is not limited in this application.

Specifically, the formula used for calculating the global mean of any difference image may be:

wherein μ g is a global mean of the difference image, M × N is a size of the difference image, i.e., a resolution of the infrared focal plane array, and imgd (i, j) is a pixel value of the coordinate point (i, j).

Specifically, the formula used for calculating the global standard deviation of any difference image may be:

Where σ g is a global standard deviation of the difference image, μ g is a global mean of the difference image, mxn is a size of the difference image, i.e., a resolution of the infrared focal plane array, and imgd (i, j) is a pixel value of the coordinate point (i, j).

optionally, in another implementation manner, the step of determining, for each frame of difference image, a blind pixel in the infrared focal plane array based on the difference image and a pixel value corresponding to each pixel element and related to the difference image may include:

For each frame of difference image, calculating the mean value and the standard deviation of the difference image in a partition mode to obtain the local mean value and the local standard deviation of the difference image;

Calculating a fourth difference value of the pixel value of the difference image and the target local mean value corresponding to each pixel element, judging whether the fourth difference value is larger than a second preset multiple of the target local standard deviation, and if so, determining the pixel element as a blind pixel;

Wherein the target local mean is: the corresponding difference image area comprises a local mean value of the pixel value corresponding to the pixel;

The target local standard deviation is: the corresponding difference image area contains the local standard deviation of the pixel value corresponding to the pixel element.

wherein the second predetermined multiple may be 2 times, 3 times, 4 times, etc.; in addition, the difference image can be partitioned according to actual conditions, and the number of partitions and the partition mode are not limited in the application.

specifically, the formula used for calculating the local mean of any difference image may be:

where μ l is a local mean of the difference image, (2 × R +1) × (2 × R +1) is a size of a partition of the difference image, imgd (i, j) is a pixel value of the coordinate point (i, j), and R is a radius of the partition.

specifically, the formula used for calculating the local standard deviation of any difference image may be:

Where σ l is a local standard deviation of the difference image, μ l is a local mean of the difference image, (2 × R +1) × (2 × R +1) is a size of a partition of the difference image, imgd (i, j) is a pixel value of the coordinate point (i, j), and R is a radius of the partition.

it should be noted that, the above-mentioned determining of the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to each pixel element in the infrared focal plane array is only an example, and should not be construed as a limitation to the embodiments of the present application.

In addition, it is understood that the blind pixel detection device may perform the step of determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values corresponding to the respective pixel elements in the infrared focal plane array with respect to the difference image, for the currently obtained difference image, after obtaining the difference image each time. Of course, the blind pixel detection apparatus may also perform, after obtaining all the difference images, for each frame of difference image, a step of determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to the respective pixel elements in the infrared focal plane array.

in the scheme provided by the embodiment, a plurality of frames of target images of auxiliary objects are obtained; wherein, any frame of target image is: under a preset environment temperature, sensing an image related to the auxiliary object by an infrared focal plane array in the infrared thermal imaging equipment, wherein different frames of target images correspond to different preset environment temperatures; calculating at least one frame of difference image corresponding to the multiple frames of target images, wherein any frame of difference image is an image obtained by subtracting two frames of target images; and determining blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to the pixel elements in the infrared focal plane array and related to the difference image for each frame of difference image. In the scheme, the blind pixels in the infrared focal plane array are determined based on the difference relationship of the pixel data sensed by the pixels in the infrared focal plane array at different preset environmental temperatures, so that the blind pixels of the infrared focal plane array in different temperature environments can be quickly and effectively detected.

In addition, in order to ensure the imaging temperature dynamic range and the response capability of the infrared focal plane array in the whole working temperature range, the working temperature range of the infrared focal plane array can be partitioned to obtain at least two temperature partitions. Further, selecting at least two temperatures from each temperature zone as predetermined ambient temperatures; and target equipment parameters of the infrared thermal imaging equipment are different under different temperature zones. Specifically, the type of target device parameter may include one or more of integration time, integration capacitance, pixel bias, blind pixel bias, on-chip correction parameters, and the like. For example: assuming that the type of the target device parameter is integration time, the integration time of the infrared thermal imaging device in temperature partition 1 may be t1, and the integration time of the infrared thermal imaging device in temperature partition 2 may be t 2.

Because different temperature partitions correspond to different target device parameters, when the ambient temperature of the infrared thermal imaging device is adjusted according to a plurality of preset ambient temperatures, the target device parameters of the infrared thermal imaging device can also be adaptively adjusted, and then the acquisition of the target image is completed based on the target device parameters after the adaptive adjustment. The temperature sensor in the infrared thermal imaging device can be used for detecting the ambient temperature, determining the temperature partition where the detected ambient temperature is located, and adjusting the target device parameters of the infrared thermal imaging device according to the preset corresponding relation between the temperature partition and the target device parameters.

it is emphasized that the selection of the division points of the temperature divisions can follow the following principle: a. avoiding a normal temperature working area, namely, the temperature value of a normal temperature working range is not taken as a partition point; b. each temperature zone ensures the imaging temperature dynamic range of the infrared focal plane array under the condition of maximum response capability. And, considering that the responsivity of the infrared focal plane array decreases with a decrease in temperature, for the operating temperature range [ a, b ], the temperature range [ a, c ] is partitioned at a first temperature interval and the temperature range (c, b ] is partitioned at a second temperature interval in the partitioning.

Based on the processing idea that different temperature partitions correspond to different target device parameters, as shown in fig. 2, a blind pixel detection method provided in an embodiment of the present application may include the following steps:

s201, obtaining a multi-frame target image of an auxiliary object;

wherein, any frame of target image is: under a preset environment temperature, the infrared focal plane array in the infrared thermal imaging device senses images related to the auxiliary object, and different frame target images correspond to different preset environment temperatures.

S201 in this embodiment is similar to S101 in the above embodiment, except that: the method comprises the following steps that a plurality of preset ambient temperatures corresponding to a multi-frame target image belong to at least two temperature partitions, and each temperature partition comprises at least two preset ambient temperatures; and under different temperature zones, the target equipment parameters of the infrared thermal imaging equipment are different.

S202, calculating a difference image corresponding to each group of target images aiming at each group of target images, wherein the preset environmental temperature corresponding to any group of target images belongs to the same temperature zone;

in order to quickly and effectively detect the blind pixels of the infrared focal plane array in different temperature environments, the scheme provided by the embodiment of the application uses the difference relationship of the pixel data sensed by the pixels in the infrared focal plane array at different preset environmental temperatures of the same temperature zone as the basis for judging whether the pixels are blind or not. Therefore, the blind pixel detection device can calculate the difference image corresponding to each group of target images, and further perform subsequent processing by using at least one frame of difference image. When the infrared thermal imaging device generates a target image, target device parameters used in generating the target image may be recorded, or a predetermined ambient temperature corresponding to the generated target image may be recorded. In this way, at the time of blind pixel detection, a plurality of frames of target images can be divided into a plurality of groups of target images based on the recorded target device parameters or the predetermined ambient temperature.

the blind pixel detection device may perform difference processing on any two frames of images in each group of target images, or perform difference processing on two frames of target images obtained successively, which is reasonable. The difference image is obtained by subtracting two frames of target images, so that each pixel value in the difference image is a pixel difference value of the two frames of target images, and each pixel element in the infrared focal plane array has a corresponding pixel value in the difference image.

optionally, when multiple frames of target images about the auxiliary object are sequentially obtained in an ascending order or a descending order of the corresponding predetermined environmental temperatures, in order to reduce the storage space occupancy rate, the step of calculating, for each group of target images, a difference image corresponding to the group of target images may include:

And for each group of target images, after the target image is obtained for the second time, the currently obtained target image is differenced with the last obtained target image to obtain a difference image, and the last obtained target image is deleted.

It is to be understood that, after the target image is obtained, the blind pixel detection means may calculate the difference image directly using the obtained target image. Of course, since noise usually exists in the target image, in order to further improve the blind pixel detection accuracy, after the target image is obtained, the blind pixel detection apparatus may perform denoising processing on the obtained target image, and calculate a difference image based on the denoised target image. The denoising process may include, but is not limited to, mean filtering, median filtering, K-nearest neighbor smoothing filtering, symmetric nearest neighbor mean filtering, and the like.

s203, aiming at each frame of difference image, determining blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to the pixel elements in the infrared focal plane array and related to the difference image.

the blind pixel detection device has the same processing procedure for each frame of difference image. Specifically, the processing procedure may include: and determining blind pixels in the infrared focal plane array based on the difference image and the pixel values corresponding to the pixel elements in the infrared focal plane array and related to the difference image. After all difference images are processed, the blind pixel detection device can quickly and effectively detect the blind pixels of the infrared focal plane array in different temperature environments.

it should be noted that, in this embodiment, for each frame of the difference image, based on the difference image and the pixel values corresponding to the difference image in each pixel element in the infrared focal plane array, a specific implementation manner of determining the blind pixels in the infrared focal plane array may refer to the related description of S103 in the foregoing embodiment, which is not described herein again.

It is understood that the blind pixel detection device may perform the step of determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values corresponding to the respective pixel elements in the infrared focal plane array with respect to the difference image, for the currently obtained difference image, after obtaining the difference image each time. Of course, the blind pixel detection apparatus may also perform, after obtaining all the difference images, for each frame of difference image, a step of determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to the respective pixel elements in the infrared focal plane array.

in addition, for convenience of calculation, before the step of determining, for each frame of the difference image, blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to the respective pixel elements in the infrared focal plane array and related to the difference image, the method may further include:

and acquiring a gain matrix matched with the difference image for each frame of difference image, and performing data amplification processing on the difference image by using the acquired gain matrix.

At this time, for each frame of difference image, determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to the respective pixel elements in the infrared focal plane array may include: and determining blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to the difference image and corresponding to each pixel in the infrared focal plane array aiming at the difference image obtained after amplification processing of each frame of data.

Optionally, in an implementation manner, all difference images may correspond to the same gain matrix, and the preset gain matrix may be set according to an empirical value, which is not limited in this application.

optionally, in another implementation, different target device parameters correspond to different gain matrices, that is, different temperature zones correspond to different gain matrices. At this time, the step of acquiring the gain matrix matched with the difference image may include:

Determining target reference information, wherein the target reference information is as follows: acquiring a target device parameter utilized in a first image or a temperature partition to which a preset environment temperature corresponding to the first image belongs, wherein the first image is a target image for generating the difference image;

And determining a target gain matrix corresponding to the target reference information based on the corresponding relation between the preset reference information and the gain matrix, and taking the target gain matrix as the gain matrix matched with the difference image.

It is understood that the preset reference information and the gain matrix may correspond to: and (3) corresponding relation between preset target equipment parameters and the gain matrix, or corresponding relation between preset temperature partitions and the gain matrix.

The determining method of the gain matrix corresponding to any reference information may include:

Obtaining a first image about a first object and a second image about a second object, wherein the first image is: an image of the first object sensed by the infrared focal plane array at a first temperature; the second image is: an image of the second object sensed by the infrared focal plane array at a first temperature; the temperature of the first object is lower than the first temperature, the temperature of the second object is higher than the first temperature, and the first temperature is the temperature in the temperature partition corresponding to the current reference information;

Calculating a gain value corresponding to each pixel in the infrared focal plane array according to a preset calculation mode to obtain a gain matrix;

the predetermined calculation method may include:

determining a first difference value of the pixel mean value of the second image and the pixel mean value of the first image;

calculating a second difference value between the pixel value of the second image and the pixel value of the first image corresponding to the pixel;

and taking the ratio of the first difference value to the second difference value as a gain value corresponding to the pixel. It should be noted that the calculation formula corresponding to the predetermined calculation method may be as follows:

the gain (i, j) is a gain value corresponding to a pixel with a coordinate (i, j), mean (VBH) is a pixel mean value of the second image, mean (VBL) is a pixel mean value of the first image, VBH (i, j) is a pixel value related to the second image corresponding to the pixel with the coordinate (i, j), and VBL (i, j) is a pixel value related to the first image corresponding to the pixel with the coordinate (i, j).

for convenience of understanding, the following describes a determination method of a gain matrix corresponding to any reference information, taking the reference information as a temperature partition and a target device parameter as examples.

(1) taking the reference information as the temperature partition as an example:

Assuming that the temperature partition is (30 ℃,50 ℃), when calculating the gain matrix corresponding to the temperature partition, selecting a temperature from the temperature partition: 40 ℃ and taking the selected temperature as the first temperature;

adjusting the temperature of the first object to 25 ℃ and the temperature of the second object to 55 ℃;

Sensing an image about the first object by the infrared focal plane array at an ambient temperature of 40 ℃, and taking the sensed image as a first image;

Sensing an image about the second object by the infrared focal plane array at an ambient temperature of 40 ℃, and taking the sensed image as a second image;

and according to a preset calculation mode, calculating a gain value corresponding to each pixel in the infrared focal plane array by using the first image and the second image to obtain a gain matrix corresponding to a temperature partition (30 ℃,50 ℃).

(2) taking the reference information as the target device parameter as an example:

Assume that the target equipment parameter is a1, which corresponds to a temperature partition of (20 ℃,30 ℃);

when calculating the gain matrix corresponding to the target device parameter a1, a temperature is selected from the temperature partitions (20 ℃,30 ℃): 22 ℃ and taking the selected temperature as the first temperature;

adjusting the temperature of the first object to 20 ℃ and the temperature of the second object to 40 ℃;

sensing an image about the first object by the infrared focal plane array at an ambient temperature of 22 ℃, and taking the sensed image as a first image;

at an ambient temperature of 22 ℃, sensing an image about the second object by the infrared focal plane array, and taking the sensed image as a second image;

and according to a preset calculation mode, calculating a gain value corresponding to each pixel in the infrared focal plane array by using the first image and the second image to obtain a gain matrix corresponding to the target equipment parameter A1.

It should be noted that the first object and the second object may be objects with uniform radiation properties, such as: and (4) a uniform radiation surface. Also, in order to ensure uniform radiation, the first object and the second object may be objects formed using only one material, but are not limited thereto. In addition, the first object and the second object can be fixed by manual fixing or a specific fixing device, so that the first object and the second object can stably block the optical path of the infrared thermal imaging device.

In the solution provided in this embodiment, the blind pixels in the infrared focal plane array are determined based on the difference relationship between the pixel data sensed by the pixels in the infrared focal plane array at different predetermined environmental temperatures of the same temperature zone. Therefore, on the premise of ensuring the imaging temperature dynamic range and the response capability of the infrared focal plane array in the whole working temperature range, the blind pixels of the infrared focal plane array in different temperature environments can be quickly and effectively detected.

Corresponding to the method embodiment, the embodiment of the application also provides a blind pixel detection device. As shown in fig. 3, the blind pixel detecting apparatus may include:

a target image obtaining unit 310 for obtaining a plurality of frames of target images regarding the auxiliary object; wherein, any frame of target image is: under a preset environment temperature, images which are induced by an infrared focal plane array in the infrared thermal imaging equipment and are related to the auxiliary object, and different frames of target images correspond to different preset environment temperatures;

a difference image calculating unit 320, configured to calculate at least one frame of difference image corresponding to the multiple frames of target images, where any frame of difference image is an image obtained by subtracting two frames of target images;

a blind pixel determining unit 330, configured to determine, for each frame of difference image, a blind pixel in the infrared focal plane array based on the difference image and a pixel value of the difference image corresponding to each pixel element in the infrared focal plane array.

in the embodiment of the application, multi-frame target images related to auxiliary objects are obtained; wherein, any frame of target image is: under a preset environment temperature, sensing an image related to the auxiliary object by an infrared focal plane array in the infrared thermal imaging equipment, wherein different frames of target images correspond to different preset environment temperatures; calculating at least one frame of difference image corresponding to the multiple frames of target images, wherein any frame of difference image is an image obtained by subtracting two frames of target images; and determining blind pixels in the infrared focal plane array based on the difference image and pixel values corresponding to the pixel elements in the infrared focal plane array and related to the difference image for each frame of difference image. In the scheme, the blind pixels in the infrared focal plane array are determined based on the difference relationship of the pixel data sensed by the pixels in the infrared focal plane array at different preset environmental temperatures, so that the blind pixels of the infrared focal plane array in different temperature environments can be quickly and effectively detected.

optionally, a plurality of predetermined ambient temperatures corresponding to the multi-frame target images belong to at least two temperature zones, and each temperature zone includes at least two predetermined ambient temperatures; under different temperature zones, the target equipment parameters of the infrared thermal imaging equipment are different;

the difference image calculating unit 320 may include:

And the difference image calculation subunit is used for calculating a difference image corresponding to each group of target images, wherein the preset environmental temperature corresponding to any group of target images belongs to the same temperature partition.

optionally, the target image obtaining unit is specifically configured to:

Sequentially obtaining multi-frame target images related to the auxiliary objects according to the ascending order or the descending order of the corresponding preset environmental temperatures;

The difference image calculation subunit is specifically configured to:

and for each group of target images, after the target image is obtained for the second time, the currently obtained target image is differenced with the last obtained target image to obtain a difference image, and the last obtained target image is deleted.

Optionally, the blind pixel detection apparatus provided in this embodiment of the present application may further include:

and the gain unit is used for acquiring a gain matrix matched with the difference image for each frame of difference image and performing data amplification processing on the difference image by using the acquired gain matrix before the step of determining the blind pixels in the infrared focal plane array based on the difference image and the pixel values of the difference image corresponding to the pixel elements in the infrared focal plane array by the blind pixel determination unit.

optionally, the obtaining, by the gain unit, a gain matrix matched with the difference image specifically includes:

Determining target reference information, wherein the target reference information is as follows: acquiring a target device parameter utilized in a first image or a temperature partition to which a preset environment temperature corresponding to the first image belongs, wherein the first image is a target image for generating the difference image;

and determining a target gain matrix corresponding to the target reference information based on the corresponding relation between the preset reference information and the gain matrix, and taking the target gain matrix as a gain matrix matched with the difference image.

optionally, the determining manner of the gain matrix corresponding to any reference information includes:

Obtaining a first image about a first object and a second image about a second object, wherein the first image is: an image of the first object sensed by the infrared focal plane array at a first temperature; the second image is: an image of the second object sensed by the infrared focal plane array at a first temperature; the temperature of the first object is lower than the first temperature, the temperature of the second object is higher than the first temperature, and the temperature of the first object in the temperature partition corresponding to the current reference information of the first temperature;

according to a preset calculation mode, calculating a gain value corresponding to each pixel in the infrared focal plane array to obtain a gain matrix;

The predetermined calculation method comprises the following steps:

Determining a first difference value of the pixel mean value of the second image and the pixel mean value of the first image;

Calculating a second difference value between the pixel value of the second image and the pixel value of the first image corresponding to the pixel;

and taking the ratio of the first difference value to the second difference value as a gain value corresponding to the pixel.

Optionally, the blind pixel determination unit includes a first determination unit;

the first determination unit is configured to:

Calculating a global mean and a global standard deviation of the difference image for each frame of difference image;

And aiming at each pixel element in the infrared focal plane array, calculating a third difference value of the pixel value of the difference image corresponding to the pixel element and the global mean value, judging whether the third difference value is greater than a first preset multiple of the global standard deviation, and if so, determining that the pixel element is a blind pixel.

Optionally, the blind pixel determination unit includes a second determination unit;

the second determination unit is configured to:

For each frame of difference image, calculating the mean value and the standard deviation of the difference image in a partition mode to obtain the local mean value and the local standard deviation of the difference image;

calculating a fourth difference value of a pixel value of the difference image corresponding to each pixel element in the infrared focal plane array and a target local mean value, judging whether the fourth difference value is larger than a second preset multiple of a target local standard deviation or not, and if so, determining that the pixel element is a blind pixel;

wherein the target local mean is: the corresponding difference image area comprises a local mean value of the pixel value corresponding to the pixel;

The target local standard deviation is: the corresponding difference image area contains the local standard deviation of the pixel value corresponding to the pixel element.

in addition, an electronic device is provided in the embodiments of the present application, as shown in fig. 4, and includes a processor 410, a communication interface 420, a memory 430, and a communication bus 440, where the processor 410, the communication interface 420, and the memory 430 complete communication with each other through the communication bus 440,

a memory 430 for storing computer programs;

The processor 410 is configured to implement the steps of the method for detecting blind pixels provided in the embodiment of the present application when executing the program stored in the memory 430.

the communication bus mentioned in the electronic device may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The communication bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown, but this does not mean that there is only one bus or one type of bus.

The communication interface is used for communication between the electronic equipment and other equipment.

the Memory may include a Random Access Memory (RAM) or a Non-Volatile Memory (NVM), such as at least one disk Memory. Optionally, the memory may also be at least one memory device located remotely from the processor.

The Processor may be a general-purpose Processor, including a Central Processing Unit (CPU), a Network Processor (NP), and the like; but also Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other Programmable logic devices, discrete Gate or transistor logic devices, discrete hardware components.

in addition, a computer-readable storage medium is provided, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the steps of the blind pixel detection method provided in the embodiments of the present application are implemented.

it is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

all the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

The above description is only for the preferred embodiment of the present application, and is not intended to limit the scope of the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application are included in the protection scope of the present application.