JP5600973B2 - Image processing apparatus and image processing method - Google Patents

Description

  The present invention relates to an image processing apparatus and an image processing method.

  Conventionally, there are image processing apparatuses that add image codes such as barcodes. This barcode includes bibliographic information such as a user name, output date and time, and a management number. As a result, when an image to which a barcode is added is read and printed by a scanner or the like, the barcode can be detected and decoded information can be used for the printing process.

  By the way, when a bar code is added, image information of the added area is lost. Therefore, there is a technique such as an image processing apparatus that embeds information on an image at a position where a barcode is added as an electronic watermark in the image to which the barcode is added.

  For example, Japanese Patent No. 3554753 (Patent Document 1) discloses an invention of an image processing apparatus or the like that embeds a watermark after compressing an image of a region that is missing with a barcode.

  However, in the invention such as the image processing apparatus disclosed in Patent Document 1, the amount of image information in the area to which the barcode is added is not considered. Thus, for example, when there is a lot of image information in the added area, it may not be embedded in an image to be processed as a digital watermark.

  The present invention has been invented in order to solve these problems in view of the above points, and has as its object to provide an image processing apparatus and an image processing method that prevent loss of information due to addition of image codes. Yes.

In order to achieve the above object, the image processing apparatus of the present invention employs the following configuration. An image processing apparatus according to the present invention is an image processing apparatus for adding an image code to a processed image, the image code acquiring means for acquiring the image code, and a region image for each small region obtained by dividing the processed image A feature acquisition unit that acquires the feature of the region, a region selection unit that selects, as the additional region, one or more regions to which an image code is added among the small regions based on the feature, and information on the region image of the additional region. Watermark embedding means for embedding in the processed image as a digital watermark; a synthesis mode for combining the acquired image code with the processed image according to the processed image; an erasing mode for erasing the image code included in the processed image; Or it can be set as the structure which has an image synthetic | combination means which performs the rewriting mode which rewrites the image code contained in the said processed image .

  Accordingly, it is possible to provide an image processing apparatus that prevents information loss due to addition of an image code.

  In order to solve the above problem, the present invention may be an image processing method in the image processing apparatus.

  According to the image processing apparatus and the image processing method of the present invention, it is possible to provide an image processing apparatus and an image processing method in the image processing apparatus that prevent loss of information due to addition of an image code.

FIG. 1 is a diagram showing an outline of a configuration of an image processing apparatus 1 according to the present embodiment. FIG. 2 is a diagram for explaining an image processed by a job executed by the image processing apparatus 1 (part 1). FIG. 3 is a second diagram illustrating an image processed by a job executed by the image processing apparatus 1. FIG. 4 is a diagram (part 3) for explaining an image processed by a job executed by the image processing apparatus 1. FIG. 5 is a diagram illustrating an example of the configuration of the scanner control unit 12. FIG. 6 is a diagram for explaining divided areas where the feature extraction unit 26 extracts features. FIG. 7 is a flowchart for explaining processing for determining a region to which a barcode is added by feature extraction. FIG. 8 is a diagram illustrating an example in which a region to which no barcode is added is provided in the processed image. FIG. 9 is a diagram illustrating an example of the configuration of the plotter control unit 19. FIG. 10 is a diagram illustrating a process for synthesizing a barcode. FIG. 11 is a diagram illustrating a process for deleting a barcode. FIG. 12 is a diagram for explaining a barcode replacement process.

  Hereinafter, the present embodiment will be described with reference to the drawings. In the following embodiments, “interface” is abbreviated as “I / F”, and “DMA controller” is abbreviated as “DMAC”.

[Embodiment]
FIG. 1 is a diagram showing an outline of a configuration of an image processing apparatus 1 according to the present embodiment. The image processing apparatus 1 in FIG. 1 includes a scanner device 11, a scanner control unit 12, a bus control unit 13, a CPU 14, a RAM 15, a ROM 16, an HDD 17, a plotter device 18, and a plotter control unit 19.

  The scanner device 11 optically reads an image and outputs image data. The scanner control unit 12 controls the scanner device 11 and performs image processing including correction for image data output from the scanner device 11.

  The bus control unit 13 controls a bus that connects each unit included in the image processing apparatus 1. The CPU 14 controls each part of the image processing apparatus 1 and controls jobs executed by the image processing apparatus 1 by executing a computer program.

  The RAM 15 is a work memory when the CPU 14 executes a computer program. The RAM 15 is also used for DMA processing executed by the scanner control unit 12 and the plotter control unit 19.

  The ROM 16 stores various data. The ROM 16 stores a computer program executed by the CPU 14. The HDD 17 stores image data processed by the image processing apparatus 1, job history, and the like.

  The plotter control unit 19 controls the plotter device 18. The plotter control unit 19 performs color space conversion, correction, gradation processing, and the like on the image data output from the plotter device 18. The plotter device 18 forms and outputs an image on a medium.

  2 to 4 are diagrams for explaining an image processed by a job executed by the image processing apparatus 1. FIG. 2 shows an example in which an image without a barcode is read from the scanner device 11, the barcodes are combined, and output from the plotter device 18. FIG. 3 shows an example in which an image combined with a barcode is read from the scanner device 11, the barcode is erased and output from the plotter device 18. FIG. 4 shows an example in which an image combined with a barcode is read from the scanner device 11, a new barcode is synthesized, and output from the plotter device 18.

  FIG. 5 is a diagram illustrating an example of the configuration of the scanner control unit 12. The scanner control unit 12 includes a scanner device I / F 21, a scanner image processing unit 22, a scanner input DMAC 23, a bus I / F 24, a barcode detection unit 25, a feature extraction unit 26, a digital watermark decoding unit 27, and a code DMAC 28. .

  The scanner apparatus I / F 21 is an interface with the scanner apparatus 11 and receives read image data. The scanner image processing unit 22 performs image processing such as background removal and shading correction on the image data read by the scanner device 11.

  The scanner input DMAC 23 implements a DMA process in which image data processed by the scanner image processing unit 22 is input / output from the bus I / F 24 and written to the RAM 15. The bus I / F 24 is an interface to the bus control unit 13 and performs input / output of image data, input of control signals, and the like.

  The barcode detection unit 25 detects a barcode from the image data processed by the scanner image processing unit 22 and acquires information included in the barcode. The barcode detection unit 25 includes a detection processing unit 251, a position register 252, a size register 253, and a code register 254.

  The detection processing unit 251 detects the barcode by detecting a predetermined feature of the barcode from the image data. The detection processing unit 251 acquires information on the position of the barcode image data, information on the size of the barcode, and information on the barcode code itself.

  The position register 252 stores information on the barcode position acquired by the detection processing unit 251. The size register 253 stores barcode size information acquired by the detection processing unit 251. The code register 254 stores information on the barcode code itself.

  The feature extraction unit 26 includes a feature extraction processing unit 261. The feature extraction unit 26 further includes a plurality of region score registers 262. The feature extraction unit 26 divides the image of the image data processed by the scanner image processing unit 22 into a plurality of regions, and extracts features for each region. The features extracted by the feature extraction processing unit 261 are, for example, the amount of data after compression (code amount) when compressing the image of the region for each region, the amount related to the edge included in each region, and the This is the amount related to the histogram for each region.

  When the feature extraction processing unit 261 extracts the compressed data amount as a feature, for example, a variable length encoding process is performed for each region, and each code amount is acquired. In a region where the density is constant and a region where there is little local change, the code amount is small. Therefore, the code amount of the image in the area to be overwritten by adding the barcode is determined by determining the position of the barcode when adding the barcode and the size of the barcode using the information of the code amount. Can be small. Thereby, it is possible to reduce the amount of code when embedding the code of the area as a digital watermark, and it is possible to prevent the code amount from being embedded and not being embedded as a digital watermark.

  When the feature extraction processing unit 261 extracts an amount related to an edge as a feature, for example, the feature extraction processing unit 261 performs edge extraction processing for each region, and totals the number of pixels determined to be pixels related to the edge. As the density change in the region is more severe, the number of edges increases and the number of pixels related to the edges increases. When the density in the region is uniform, the number of pixels related to the edge becomes small. As the density is constant, the amount of code of a code generated when coding the area is reduced, so that it is possible to prevent the code of the area from being embedded as a digital watermark.

  When the feature extraction processing unit 261 extracts the amount related to the histogram as the feature, for example, the number of pixels having the most concentrated density is extracted from the density histogram for each region. The greater the density change in the region, the wider the density distribution and the smaller the number of pixels with a specific density. On the other hand, the smaller the density change in the region, the smaller the density distribution and the greater the number of pixels with a specific density. As a result, an area with little change in density is selected and a barcode is added, so when an image in that area is encoded and embedded as a digital watermark, the amount of code can be reduced, preventing the electronic watermark from being embedded. can do.

  The region score register 262 has a plurality of registers. These registers hold the extracted features for each divided region processed by the feature extraction unit 26. These registers may be, for example, an area 1 score register, an area 2 score register,..., An area n score register, and numbers corresponding to each area.

  The digital watermark decoding unit 27 acquires and decodes the digital watermark embedded in the image data processed by the scanner image processing unit 22 and acquires the information. This information is obtained by encoding image information of an area to which a barcode is added. The code DMAC 28 inputs / outputs a code obtained by decoding to the RAM 15 via the bus I / F 24 when the digital watermark decoding unit 27 performs decoding processing of the digital watermark. This process is a DMA transfer.

  FIG. 6 is a diagram for explaining divided areas where the feature extraction unit 26 extracts features. In FIG. 6, the processed image p1 is divided into vertical n and horizontal m, and feature extraction is performed for each of the n × m regions. In the raster order from the upper left of FIG. 6, area 0, area 1,. This number may correspond to the number assigned to a plurality of registers included in the region score register 262.

  Note that the size of each area shown in FIG. 6 is smaller than the size of the barcode. Therefore, in the present embodiment, an area extending over a plurality of areas is set as an area to which a barcode is added. The feature extraction processing unit 261 performs feature extraction for each region, and stores the score in the region score register 262.

  FIG. 7 is a flowchart for explaining processing for determining a region to which a barcode is added by feature extraction. The processing in FIG. 7 is realized by the barcode generation unit 95. In step S1 of FIG. 7, the initial value of SCNUM, which is the minimum score, is determined.

  When the feature is a code amount, the initial value of SCNUM is (embeddable code amount + 1). The code amount that can be embedded may be a predetermined amount that is determined in advance, and may be, for example, the maximum amount when an electronic watermark is embedded in the entire processed image. Moreover, the quantity of a predetermined ratio may be sufficient with respect to the maximum quantity.

  When the feature is the number of pixels related to the edge, the initial value of SCNUM is the number of all pixels in the area. When the feature is an amount related to the histogram, the initial value of SCNUM is set to zero.

  Progressing to step S2 following step S1, an area corresponding to the barcode size is selected. The area corresponding to the barcode size is an area in which one or more areas shown in FIG. 6 are combined. In the process of FIG. 7, one area is processed every time step S <b> 2 is passed.

  Progressing to step S3 following step S2, the score of the feature of the area selected in step S2 is calculated. This feature is, for example, a code amount after compression, an amount related to an edge, or an amount related to a histogram. These values are calculated in advance for each area shown in FIG. 6 and stored in the area score register 262. That is, the feature for each area is acquired by adding the value of the feature for each region included in the area.

  Progressing to step S4 following step S3, it is determined whether or not the feature value acquired in step S3 has a predetermined relationship with SCNUM. When the feature is a code amount, the predetermined relationship is “feature value is smaller than SCNUM”. If the feature is an amount related to an edge, the predetermined relationship is “feature value is greater than SCNUM”. When the feature is an amount related to the histogram, the predetermined relationship is “feature value is smaller than SCNUM”. If the predetermined relationship is satisfied, the process proceeds to step S5, and if not, the process proceeds to step S6.

  In step S5 following step S4, the SCNUM value is set as the score obtained in step S3, and the area candidate to which the barcode is added is set as the current area.

  In step S6 following step S4 or step S5, the area from which features are acquired is shifted to the right. In the case of the right end, it shifts downward and returns to the left end.

  Progressing to step S7 following step S6, it is determined whether or not the processing has been completed up to the final area. If the process has been completed, the process proceeds to step S8. If the process has not been completed, the process returns to step S2 to repeat the process.

  In step S8 following step S7, it is determined whether or not the SCNUM value calculated up to step S7 satisfies a predetermined condition. When the feature is a code amount, the predetermined condition is whether or not SCNUM is smaller than a predetermined value. When the feature is a pixel related to an edge, the predetermined condition is, for example, that SCNUM is 0. That is, an area that does not include an edge is selected. When the feature is an amount related to the histogram, the predetermined condition is that SCNUM is a value of the total number of pixels in the area. That is, an area where the density of pixels in the area is uniform is selected.

  If the SCNUM satisfies a predetermined condition, the process proceeds to step S9. If the SCNUM does not satisfy the predetermined condition, the process proceeds to step S10.

  In step S9 following step S8, the area to which the barcode is added is determined. In step S9, the barcode size is further determined. On the other hand, in step S10 following step S8, the barcode size is set small, and the initial value of the area is set to 0 (upper left position).

  FIG. 8 is a diagram illustrating an example in which a region to which no barcode is added is provided in the processed image. In FIG. 8, a region a1 to which no barcode is added is provided in the image p1 shown in FIG. The region a1 is a region that is not subject to feature extraction processing.

  FIG. 9 is a diagram illustrating an example of the configuration of the plotter control unit 19. The plotter control unit 19 includes a bus I / F 91, a plotter output DMAC 92, a barcode area extraction unit 931, a variable length encoding unit 932, a digital watermark generation unit 933, a barcode area deletion unit 941, a digital watermark removal unit 942, a barcode. A generation unit 95, a code DMAC 96, a code decoding unit 97, and an image synthesis unit 98 are included.

  The bus I / F 91 is an interface to the bus managed by the bus control unit 13. When the plotter output DMAC 92 prints and outputs an image from the plotter device 18, the plotter output DMAC 92 acquires the image data stored in the RAM 15 by DMA transfer, and performs processing such as barcode addition.

  The barcode area extraction unit 931, the variable length encoding unit 932, and the digital watermark generation unit 933 extract the image of the area to which the barcode is added, perform variable length encoding, and embed it in the processed image as a digital watermark . The barcode area extraction unit 931 extracts an image of an area to which a barcode is added. The area to which the barcode is added is determined by the CPU 14 executing the process of FIG.

  The variable length coding unit 932 performs variable length coding on the image of the area to which the barcode extracted by the barcode region extraction unit 931 is added. The digital watermark generation unit 933 converts the variable length code generated by the variable length encoding unit 932 into data to be embedded as a digital watermark.

  The barcode area erasing unit 941 erases the barcode included in the image data input from the bus I / F 91 from the image data. The bar code position and size are detected by the bar code detector 25. When the barcode removal is realized by overwriting the image, the process by the barcode area erasing unit 941 does not have to be performed. The digital watermark removing unit 942 erases the digital watermark information acquired by the digital watermark decoding unit 27 from the image data.

  The barcode generation unit 95 generates a barcode. The barcode generation unit 95 includes a barcode image generation unit 951, a position register 952, a size register 953, and a code register 954. The barcode image generation unit 951 encodes information to be added as a barcode and generates a barcode image.

  The position register 952 and the size register 953 hold the position information of the area to which the barcode is added and the barcode size information, respectively. The code register 954 holds the barcode information itself.

  The barcode image generated by the barcode image generation unit 951 and information on the position and size of the barcode are input to the image composition unit 98.

  The code DMAC 96 reads the code obtained by the digital watermark decoding unit 27 decoding the digital watermark from the RAM 15 and outputs the code to the code decoding unit 97. The code DMAC 96 realizes this processing by DMA transfer.

  The code decoding unit 97 decodes the code read from the RAM 15 by the code DMAC 96, and decodes the image of the area to which the barcode is added. The image data of the decoded area is input to the image composition unit 98.

  The image composition unit 98 generates image data to be printed out by the plotter device 18. The image synthesis unit 98 synthesizes data output from the digital watermark generation unit 933, the digital watermark removal unit 942, the barcode generation unit 95, and the code decoding unit 97 to generate one image data.

  The image composition unit 98 includes a path selector 981, a composition processing unit 982, and a mode register 983. The path selector 981 selects data input to the image composition unit 98. Thereby, the data included in the output image data is switched. The composition processing unit 982 composes data input by switching by the path selector 981 to generate one image data.

  The mode register 983 holds mode information when the path selector 981 performs switching. The modes include “bar code synthesis mode”, “bar code erasing mode”, and “bar code rewriting mode”. In the “barcode synthesis mode”, the barcode image generated by the barcode generation unit 95 is combined with the input image data.

  In the “barcode synthesis mode”, processing is mainly executed by the digital watermark removing unit 942 and the code decoding unit 97.

  FIG. 10 is a diagram illustrating a process for synthesizing a barcode. An image P21 in FIG. 10 is an image of image data read from the RAM 15 by the plotter output DMAC 92. The image P22 is an image of an area extracted by the barcode area extraction unit 931. The image data of this image is variable-length encoded and becomes a digital watermark.

  An image P23 in FIG. 10 is a barcode image generated by the barcode generation unit 95. This barcode image is added to the area where the image is extracted by the barcode area extraction unit 931. The image P24 is an image in which the barcode image P24 is added to the image P21 and a digital watermark based on the image P22 is embedded.

  “Barcode erasure mode” is an area where the barcode is added to the image generated from the code obtained by erasing the barcode image included in the input image data and decoding the digital watermark. To draw. In the “barcode erasure mode”, the barcode erasure process is performed on the image data from which the digital watermark information has been erased.

  In the “barcode erasure mode”, processing is mainly executed by the barcode area extraction unit 931, the variable length encoding unit 932, the digital watermark generation unit 933, and the barcode generation unit 95.

  FIG. 11 is a diagram illustrating a process for deleting a barcode. An image P32 in FIG. 11 is an image of image data read from the RAM 15 by the plotter output DMAC 92. This image includes a barcode image in advance. An image P32 in FIG. 11 is an image obtained by removing the barcode image from the image P31 by the barcode area erasing unit 941.

  An image P33 in FIG. 11 is an image obtained by decoding information embedded as a digital watermark by the code decoding unit 97. The image P34 is an image obtained by adding the image decoded by the code decoding unit 97 to the image P32.

  In the “barcode rewriting mode”, the barcode image is deleted and a newly generated barcode image is added. In the “barcode rewriting mode”, when the area to which the barcode is added is changed, the embedded digital watermark is removed and the image information in the area to which the barcode is newly added is handled. Embed a digital watermark.

  In the “barcode rewriting mode”, processing is mainly executed by the barcode area extraction unit 931, the variable length coding unit 932, the digital watermark generation unit 933, the digital watermark removal unit 942, the code DMAC 96, and the code decoding unit 97. Is done.

  FIG. 12 is a diagram for explaining a barcode replacement process. An image P41 in FIG. 12 is an image of image data read from the RAM 15 by the plotter output DMAC 92. A bar code is added to the image P41 in advance, and the code of the image of the area to which the bar code is added is embedded as a digital watermark.

  The image P42 is an image obtained by erasing the barcode image of the area previously added by the barcode area erasing unit 941. The image P43 is a barcode image generated by the barcode generation unit 95.

  The image P44 is an image in which the barcode image P43 is added to the image P42. The image P44 has the same position as the image P41 where the barcode image is added. Therefore, the digital watermark embedded in the image P41 is not removed and is included in the image P44.

  Although the best mode for carrying out the invention has been described above, the present invention is not limited to the embodiment described in the best mode. Modifications can be made without departing from the spirit of the present invention.

  As described above, the image processing apparatus according to the present invention is useful for associating images with bibliographic information, and is particularly suitable for a copying machine.

DESCRIPTION OF SYMBOLS 1 Image processing apparatus 11 Scanner apparatus 12 Scanner control part 13 Bus control part 18 Plotter apparatus 19 Plotter control part 22 Scanner image processing part 23 Scanner input DMAC
25 Barcode detection unit 26 Feature extraction unit 27 Digital watermark decoding unit 28 Code DMAC
92 Plotter output DMAC
95 Barcode generator 96 Code DMAC
97 Code decoding section 98 Image composition section 251 Detection processing section 252 Position register 253 Size register 254 Code register 261 Feature extraction processing section 262 Area score register 931 Barcode area extraction section 932 Variable length encoding section 933 Digital watermark generation section 941 Bar code Area deletion unit 942 Digital watermark 1-removal unit 951 Barcode image generation unit 952 Position register 953 Size register 954 Code register 981 Path selector 982 Compositing processing unit 983 Mode register

Japanese Patent No. 3554753

Claims (7)

An image processing apparatus for adding an image code to a processed image,
Image code acquisition means for acquiring the image code;
A feature acquisition means for acquiring a feature of a region image for each small region obtained by dividing the processed image;
An area selecting means for selecting one or more areas to which an image code is added as the additional area based on the characteristics;
Watermark embedding means for embedding information of the area image of the additional area into the processed image as a digital watermark;
In accordance with the processed image, a synthesis mode for combining the acquired image code with the processed image, an erasing mode for erasing the image code included in the processed image, or a rewriting mode for rewriting the image code included in the processed image And image composing means for executing
An image processing apparatus comprising: The image processing apparatus according to claim 1, wherein the image synthesizing unit executes the synthesis mode for synthesizing the acquired image code and the digital watermark with the processed image that does not include an image code. 2. The image synthesizing unit according to claim 1, wherein the image synthesizing unit erases the image code from the processed image including the image code, and executes the erasing mode in which the area image corresponding to the digital watermark is drawn in the additional area. Image processing device. The image synthesis means deletes the image code from the processed image including the image code and the digital watermark, and adds a newly generated image code to the position of the deleted image code in the processed image, thereby The image processing apparatus according to claim 1, wherein the rewriting mode for rewriting an image code included in a processed image is executed. The image code acquisition means changes the size of the image code to be smaller when the data amount of the area image information of the additional area exceeds a predetermined value,
The image processing apparatus according to claim 1, wherein the region selection unit selects one or more small regions corresponding to the changed size of the image code.   The feature is any one of a code amount when compressing the region image, an amount related to an edge included in the region image, and an amount related to a histogram of the region image. The image processing apparatus according to claim 1 or 2. An image processing method for adding an image code to a processed image,
An image code obtaining step for obtaining the image code;
A feature acquisition step of acquiring features of a region image for each small region obtained by dividing the processed image;
An area selection step of selecting one or more areas to which an image code is added as the additional area based on the characteristics,
A watermark embedding step of embedding information of the area image of the additional area into the processed image as a digital watermark;
In accordance with the processed image, a synthesis mode for combining the acquired image code with the processed image, an erasing mode for erasing the image code included in the processed image, or a rewriting mode for rewriting the image code included in the processed image Performing the steps, and
An image processing method comprising:

Images