阅读说明：本技术 调整分辨率的印刷预览 (Adjust the print review of resolution ratio ) 是由 F·克洛普纳 于 2019-05-17 设计创作，主要内容包括：本发明涉及一种用于通过计算机识别出印刷过程的工作流中不同渲染过程的图像输出之间的偏差的方法,第一渲染过程从印前阶段PDF文件生成第一图像且第二渲染过程从印前阶段PDF文件生成第二图像,包括：第一和第二图像换算成灰度图像,将大分辨率的灰度图像降低尺度到小分辨率的图像的尺寸；依据图像比较度规来量化分辨率差异的影响；计算第一与第二图像的差异图像并依据第一阈值二进制化；对差异图像采用平均值过滤器以获得每个像素周围强烈偏差的像素份额；将差异图像中周围强烈偏差的像素份额小于0.5的像素置为0；将差异图像中剩余像素分区；求取大于第二阈值的区段并作为内容偏差输出；考虑第一与第二图像的内容偏差修正印刷过程。(The method for the deviation between image output that the present invention relates to a kind of for identifying different render process in the workflow of printing process by computer, first render process generates the first image and the second render process from print last stage pdf document and generates the second image from print last stage pdf document, it include: that the first and second images are converted into gray level image, by the size of the image of the gray level image reduction scale of big resolution ratio to small resolution ratio；Compare the influence that metric carrys out quantization resolution difference according to image；Calculate the differential image of first and second image and according to first threshold binarization；Average filter is used to differential image to obtain the pixel share of strong deviation around each pixel；Pixel of the pixel share less than 0.5 of the strong deviation of surrounding in differential image is set to 0；By residual pixel subregion in differential image；It seeks the section greater than second threshold and is exported as content variation；Consider the content variation amendment printing process of first and second image.)

1. one kind for identified in the workflow of printing process by computer (1) different render process image output (7, 8) method of the deviation (9) between,

Wherein, in the first render process, the pdf document based on the print last stage generates the first image (7), also, in the second wash with watercolours During dye, the pdf document based on the print last stage generates the second image (8),

Described method includes following steps:

The first image and the second image (7,8) are converted into gray level image by the computer (1), and will be had larger The gray level image (7) of resolution ratio reduces scale to the size of the image (8) with corresponding small in resolution；

Compare metric according to image by the computer (1) come the influence of quantization resolution difference；

The differential image (10) between the first gray level image and the second gray level image (7,8) is calculated by the computer (1) And binarization is realized according to first threshold；

Average filter is used by differential image (10) of the computer (1) to binarization, it is each to obtain The proportionate share of the pixel of strong deviation around pixel；

By the computer (1) by binarization, realized average value filtering differential image (10) in, its week Pixel of the proportionate share less than 0.5 for enclosing the pixel of strong deviation is set to 0；

By the computer (1) by binarization, realized average value filtering differential image (10) in remaining picture Element carries out subregion；

The section (11) greater than previously given second threshold is sought out by the computer (1) and by the section (11) it is exported as content variation (13)；

In view of required content variation (9) got between the first image and the second image (7,8) described in amendment Printing process.

2. according to the method described in claim 1,

It is characterized in that,

After seeking out the section (11), by the computer (1) by the section (11) in the first image (7) It is marked according to bounding box.

3. according to claim 1 or method as claimed in claim 2,

It is characterized in that,

After seeking out the section (11), the quantity for the content variation (13) got as required by the computer (1) output.

4. according to the described in any item methods of preceding claims,

It is characterized in that,

The first image is related to bitmap (7) for the printing process, for executing the printing process, and institute It states the second image and is related to preview image (8), wherein the resolution ratio of the preview image (8) is significantly lower than the bitmap (7).

5. according to the described in any item methods of preceding claims,

It is characterized in that,

Pdf document is used in the workflow for printing process, and

First render process and second render process use the different rendering engines based on PDF standard.

6. according to the method described in claim 5,

It is characterized in that,

For the amendment of the printing process, only show this kind of mistake (13) in second image (7): the mistake is also deposited It is in the first image (8).

7. according to the described in any item methods of preceding claims,

It is characterized in that,

Binarization, realized that the subregion of residual pixel in the differential image (10) of average value filtering is to pass through line Coincidence method carries out.

8. according to the described in any item methods of preceding claims,

It is characterized in that,

The first threshold and the previously given second threshold are consistent.

9. according to the described in any item methods of preceding claims,

It is characterized in that,

The first threshold is calculated by the computer (1) according to quantized differences in resolution.

10. according to the described in any item methods of preceding claims,

It is characterized in that,

The method is applied multiple times, iteratively to identify all existing deviations (9).

Technical field

The present invention relates to a kind of methods of the deviation between image output for going out different render process for identification.

Technical field of the invention belongs to print last stage (Druckvorstufe).

Background technique

When handling print job, usually correspondingly located in advance in the so-called print last stage by the Workflow system of printing house Manage the data of the print job of client.This means that: the text and/or figure for constituting print job are printing the last stage in workflow It is pre-processed in this wise in system, so that print job can be directly passed to one or more printing machines, to complete the printing Task.Here, it is not important that: the processing for printing the last stage is directly to carry out in printing house, still for example in network printing (Web-to-Print) it receives in scope in central task and is carried out on server.

Here, print job be delivered to printing machine (or plate exposure machine is delivered in the case where offset printing) it Before, user (the printing personnel of processor or printing house namely at the end of the print last stage) checks: the number of print job According to whether correctly having been pre-processed by Workflow system.This usually passes through the corresponding print job data of preview and carries out.Here, by Workflow system generates a preview image (in most cases in the form of pdf document), which provides pass to user In the overview of the print job data of preprocessed completion.According to the preview image, user may recognize that preprocessed , the appearance of data that printing machine (or plate exposure machine) will be sent to.Whether user can identify data by just as a result, It really pre-processes, or whether may still need to further correct.However, the preview so generated corresponds only to the printing number of script According to, but it is not completely the same with them.Otherwise there is no need to previews by people, but can directly go to check printing machine to be sent to The script printed data of (or plate exposure machine).These script printed datas are in most cases with unpressed format (for example bitmap) generates, this is because the picture format (for example JPEG) of compression is usually associated with corresponding quality loss.Therewith On the contrary, very inefficient: showing this kind of bitmap in preview with correspondingly high memory space requirements.Therefore, preview when The compressed format reduced with resolution ratio is used on display.Used rendering when preview in Heidelberg Prinect software Engine (Rendering-Engine) with for generating identical (the Adobe PDF Print Engine) of printed data.Only join Number is different, especially resolution ratio.In addition, using Adobe InDesign or Adobe Acrobat production (or processing) PDF text When part, in order to check pdf document, other rendering engine (for example Adobe PDF Library) is in most cases used.Out In these differences, these preview images usually with it is inconsistent in the script printed data of bitmap form.In order to avoid user this When by difference be considered pre-process printed data in mistake and mistakenly carry out meaningless correction, must then identify in time This kind of deviation.In turn the case where, is even more important.If preview image about client be intended to aspect and be shown as be it is correct, But printed data includes deviation, then this point must all identify in advance anyway.

U.S. Patent application US 2004/0086156A1 is related to the known prior art about the theme.The patent Application discloses a kind of method for carrying out printing plate monitoring in the print last stage, wherein grating image processor production is in the First printing image of one resolution ratio, and the second printing image of non-rasterizing is then generated, store the print of the two rasterizings Map brushing picture, and it is then compared the printing image of the two rasterizings, so that thus, it is possible to assess the quality of grid processor.

10 218068A1 of German patent application DE is the prior art known to another kind.The patent application disclose one kind Method for exchanging the information about print last stage, printing stage and tone value and color value between the quality control stage. The basic task of this application is: improving print last stage, printing stage and the cooperation between the quality control stage.This pass through by CMYK visual texture data and the control image in the quality control stage of current color measuring instrument are compared and are achieved.Cause This, in the first step, by the way that the picture point of higher resolution image is summarized (Zusammenfassung), to make The two information reach consistent resolution ratio.If this differences in resolution is not integer relation, it is this summarize pushed away by interior Method is realized.Next, analyzing this printing image and searching for the image-region for being suitable for required analysis.

Summary of the invention

As a result, the task of the present invention is to provide a kind of method of print review for printing process, this method can be use up It may truly preview printed data to be produced.

The task is by a kind of for identifying the figure of different render process in the workflow of printing process by computer As the method for the deviation between output is addressed, wherein the pdf document based on the print last stage in the first render process generates First image, and the second image is generated based on the pdf document in the second render process, this method comprises the following steps: The first image and the second image are converted into gray level image by the computer, and by the gray level image with larger resolution ratio Scale (herunterskalieren) is reduced into the size for the image for being respectively provided with small in resolution；Compare metric according to image, Quantify the influence of this differences in resolution by the computer；The first gray level image and second are calculated by the computer Differential image between gray level image, and binarization (Binarisierung) is realized according to first threshold；Pass through the meter Calculation machine uses average filter to the differential image of binarization, to obtain the pixel of strong deviation around each pixel Proportionate share (Anteil)；By the computer by binarization, realized average value filtering differential image In around its own the proportionate share of the pixel of strong deviation be set to 0 less than those of 0.5 pixel；It will by the computer Binarization, realized that remaining pixel carries out subregion (Segmentierung) in the differential image of average value filtering；Pass through The computer seeks out the section greater than previously given second threshold and exports these sections as content variation；Consider To content variation obtained between the first image and the second image, printing process is corrected.Here, according to the method for the present invention Core is: operation (Manipulation) described differential image, so that being only left content variation as far as possible.What it was realized Mode is: will meet as far as possible the side of reality corresponding to the second image of printing image originally to be generated with high-resolution Formula (wirklichkeitsgenauen) reduces scale into the first image for corresponding to print review image with low resolution Resolution ratio.It based on this, is then acquired with multiple method and steps: wherein being existed between the first printing image and the second printing image Difference.Then, these differences are correspondingly showed into user, so that user learns: the first figure with low resolution Picture and the mistake in the difference or preparation printed data that are found between the second image with high-resolution, so it is necessary Correction.In turn, it is also possible for having the fact that wrong but printed data is correct in preview, and according to the present invention Method avoided.As a result, user can for it is made, be sent to related printing machine (or plate exposure machine) Printed data executes corrective measure, and need not worry to ignore mistake or corrected to be not present in the printed image data generated originally Spurious error.That is, having been corrected between preview image and practical printed data according to the method for the present invention by resolution ratio institute Difference that is caused, may result in printing process misspecification.

This method advantageous and it is therefore preferable that specification of the improvement project by dependent claims and with attached drawing obtains Out.

Here, a kind of preferred improvement project according to the method for the present invention is, and after acquiring these sections, these areas Section is marked in the first image according to bounding box (Begrenzungsboxen) by the computer.It is a kind of effectively to give display User before device shows that the mode of the deviation found between the first image and the second image is: by these deviations by side Boundary's frame is marked.Herein it is also feasible that: when clicking each bounding box for showing corresponding deviation, to using on this position Person shows based on the part of corresponding high-resolution bitmap (i.e. the second image), is used for visual comparison.User can be accurate as a result, Identify the difference between the first image with low resolution and the second image with high-resolution in ground.

Here, the preferred improvement project of another kind according to the method for the present invention is: after acquiring these sections, by institute State the quantity that computer exports obtained content variation.It is additional to or is alternatively to required by being shown over the display by bounding box The deviation obtained, can also show the quantity of content variation between the first image and the second image to user.For example, if only asked The deviation of very little or absolutely not deviation in the ideal case, then the difference caused by user need not check by resolution ratio And the assessment carried out to the first image script can be immediately continued with.

Here, the preferred improvement project of another kind according to the method for the present invention is that the first image is related to for printing The preview image of process, and the second image is related to the bitmap for executing printing process, wherein the resolution ratio of preview image Significantly lower than bitmap.The core of entire method is: there is very big inferior image resolution between the first image and the second image It is different, as a result, in the different render process for making the two images, it is equally possible to these content variations occur.In order to borrow Help preview image to assess made printing image, relative in existing inclined for the script of bitmap form printing image Difference certainly must be correspondingly small.At least user must be expressly understood that existing difference, that is to say, that he have to know that preview Particular error in image is not true mistake, and is only as caused by differences in resolution and different render process 's.

Here, the preferred improvement project of another kind according to the method for the present invention is, in the workflow for being directed to printing process It is middle to use pdf document, and the first render process and the second render process use the different rendering engines based on PDF standard. Because corresponding pdf document or JDF are using the PDF dedicated developed specifically for printing industry in workflow process Formula, thus the rendering engine based on PDF standard is also used, for making the preview being equally produced as pdf document.Equally make With PDF rendering engine, for during grid production be in bitmap form the second image.Usually Adobe PDF Print Engine.However, the use of the different engines based on PDF standard being also feasible.In case of such case, then this is equally possible It can be the reason of there are deviations between the first printing image and the second printing image (namely preview image and printing bitmap).

Here, the preferred improvement project of another kind according to the method for the present invention is those of only to correct in the first image The mistake in the second image is existed in, to correct printing process.Meaning according to the method for the present invention is: should use up can The mistake in bitmap (namely script printed data) can be found always, even if they are in preview image due to image resolution ratio And/or render process difference and do not occur.It those of should also be as in discovery preview image being not present in false positive in bitmap Mistake.Certainly, this kind of false positive mistake should not be also corrected, but should only correct and exist in bitmap in preview image Reflect those of true mistake mistake in turn in data.It is necessary, of course, to correct these true mistakes in bitmap data always Accidentally, even if they are not present in preview image again.Therefore, when comparing two image (i.e. bitmaps and preview image), always Show all difference.

Here, the preferred improvement project of another kind according to the method for the present invention is, to binarization, realized it is flat It is by line coincidence method that residual pixel in the differential image of mean value filtering, which carries out subregion, (Zeilenkoinzidenzverfahren) it realizes.Subregion in penultimate method and step (will be required by this subregion The content variation of taking-up is determined position) it can most preferably be carried out by line coincidence method.However, in principle, Qi Tafen Area's method is also feasible.

Here, the preferred improvement project of another kind according to the method for the present invention is, previously given first threshold and pre- First given second threshold is consistent.Experience have shown that: it can obtain making us full using same threshold value for the first and second threshold values The result of meaning.However, also it is possible that selecting different values (for example to consider the resolution of the two images for second threshold Rate).

Here, the preferred improvement project of another kind according to the method for the present invention is that first threshold is based on by computer Quantized differences in resolution is calculated.Present method be advantageous in that the threshold value or parameter without stringent rigidity need hand It adjusts and sets dynamicly, because these threshold values are determined in a dynamic fashion according to image quality metric.

Here, the preferred improvement project of another kind according to the method for the present invention is that the method is applied multiple times, to repeatedly Identify to generation all existing deviations.It is thus coarse inclined because being to select these threshold values according to the whole difference of image Difference also has an impact to it.Therefore, the generally recognized less than lesser deviation in there is the very image of large deviation.This is one and asks Topic.Nevertheless, after eliminating coarse deviation in the first round (Durchgang) according to the method for the present invention, still This method is used for multiple times in subsequent iterative step, then also reliably to seek out lesser deviation, this is proved to be A kind of good means.Here, take second place heel row except coarse deviation in the first round, this be by operate made PDF and By the way that the made PDF for correspondingly continuing to apply to be subsequently operated according to the method for the present invention is achieved.

Detailed description of the invention

At least one preferred embodiment, which is based on, with reference next to attached drawing further describes such invention and the invention Structure and/or functionally it is advantageously improved scheme.In the accompanying drawings, mutual corresponding element is respectively with identical appended drawing reference table Show.

Attached drawing is shown:

Fig. 1: the example of ink jet printer system structure；

Fig. 2: the example of the deviation based on rendering；

Fig. 3: in the example of the printing image (gray level image) of bitmap form；

Fig. 4: in the example of the printing image of preview image form；

Fig. 5: the example of differential image；

Fig. 6: the example of the deviation of subregion；

Fig. 7: there is the example of the printing image of the preview image form of labeled deviation；

Fig. 8: schematic flow according to the method for the present invention.

Specific embodiment

The ink-jet printer 3 being used in particular workflow system according to the method for the present invention.Such workflow Exemplary system it is shown in FIG. 1.The Workflow system is in one or more computers 1 for handling corresponding print job 5 Upper operation.Here, the print job 5 that should be printed on ink-jet printer 3 is by 2 rasterizing of grating image processor, and this The printing image 4 of rasterizing is passed to ink-jet printer 3 from this and carries out corresponding formal printing a bit.

Preferred implementation modification according to the method for the present invention in fig. 8 referring to single method step again schematically It shows.

These method and steps include following main points:

1) by the resolution ratio of higher gray level image I (x, y) the reduction scale of resolution ratio to preview image J (x, y).In bitmap The gray level image of 7 forms is shown in FIG. 3, and preview image 8 is shown in FIG. 4.

2) structural similarity index SSIM (I, J) is calculated

3) calculate differential image 10D (x, y)=| I (x, y) J (x, y) |

Binarization: D (x, y)=0, if D (x, y) < 255* (1SSIM (I, J))

1, otherwise } (referring to Fig. 5)

4) use size for the average filter of 7x7: S (x, y)=mean_7x7 (D (x, y))

5) binarization: S (x, y)=0, if S (x, y) < 0.5

1, otherwise }

6) subregion (referring to Fig. 6) is carried out to image by line coincidence method

7) area (pixel quantity) of these sections is determined, and

Area is less than to the section zero setting of 255* (1-SSIM (I, J))

8) remaining section 11 in preview image 12 is marked with bounding box.This is sketched out in Fig. 5, herein can be well See the deviation 13 for detecting and being marked.In addition, when clicking bounding box, being shown in particularly preferred expansion modification Part in high-resolution bitmap 7 is with making comparisons.

Hereafter, user can execute PDF based on the deviation 9 that is shown or renderer tune set in change and eliminate deviation. Then, which ensure that: mistake is excluded before printing process rather than after printing process, when thus significantly having saved Between and cost.

This important explanation is: in Fig. 3 it can be seen that spike, as the deviation 9 of bitmap 7 be the deviation 6 based on rendering Example and generated by oblique angle connection (Miter-Join), two lines to meet connect in the oblique angle junction.In addition, This shows again in Fig. 2.If the angle between these lines is very sharp, the tip of this oblique angle connection can be grown very much. In order to avoid this point, (Miter-Limit) is limited the quantity equipped with the so-called oblique angle for limiting this length.That is, passing through choosing Lesser oblique angle limitation is selected, or the angle between the line segment by making vector form is not excessively sharp, and can eliminate Fig. 3 image In spike.

Disclosed method preferably recognizes coarse content variation 9, example than in the prior art according to the method for the present invention Such as strong deformation or the object of disappearance.In addition, the quantity for being wrongly recognized into the image-region of dependent deviation is seldom.By according to According to image quality metricAutomatically determine threshold value, this also enables this method to compare It is used for greater flexibility for for example other methods used in the prior art.

However, because being to select these threshold values according to the whole difference of these images 7,8, thus coarse deviation 9 Have an impact to it.Therefore, in having the very image 7,8 of large deviation 9, often identification is less than lesser deviation 9.In order to avoid this A bit, in the implementation modification of another kind supplement, by being applied multiple times after operating PDF to eliminate coarse deviation 9 according to this The method of invention knows all deviations 9 iteratively to debate.In addition, this method (is in threshold value shape in other implementation modification Formula) parameter can manually be adapted to.This can for example be carried out in user interface.Identification susceptibility may be selected in user as a result,.

In addition to this, can theoretically be compared by the parameter of analysis pdf document and rendering engine to bypass image.So And because periodically use new version renderer, thus solution must be periodically adapted to.By using structural similarity index Parameter is selected in (SSIM, Structural Similarity Index) automation, this gives satisfactory knot in an experiment Thus fruit only just needs manually to adjust setting parameter under special circumstances.

Reference signs list

1 computer

2 grating image processors (RIP)

3 printing machines

The printing image of 4 rasterizings

5 print jobs

6 deviations based on rendering

7 bitmaps

8 preview images

Deviation between 9 bitmaps and preview image

Differential image between 10 bitmaps and preview image

11 detected and institute's subregion deviations

12 have the preview image of deviation marked, detected

The 13 detected and deviations that are marked