JP2015049795A - Image processor, image processing system, and program - Google Patents

Abstract

The data size is reduced while preventing the contents of image data including non-character images from being unrecognizable. By analyzing image data generated by an image reading apparatus and representing target image data, a character region that is a region representing characters and a non-character image that is an image other than characters are represented. A non-character area that is an area is detected. Compressed character image data representing characters is generated by compressing a portion representing the character region of the target image data. By using the target image data, non-character image data representing a non-character image in the non-character region is acquired, and the acquired non-character image data is stored in the storage unit. Output image data including compressed character image data and storage destination data representing storage destination information, which is information representing a storage destination of non-character image data, and not including non-character image data is generated. [Selection] Figure 2

Description

  The present invention relates to processing of image data generated by an image reading apparatus.

  Conventionally, image data generated by an image reading device (for example, a scanner) has been used. For example, a technique for storing image data representing an image read by a scanner in an HTML (HyperText Markup Language) format has been proposed. Specifically, a file name is set for the image data representing the read image, the image data is stored with the file name, and HTML format data is created from information such as the storage location of the file.

JP 2004-171178 A

A technique for creating data including image data representing a read image is also known. However, the size of the image data representing the read image may increase. there,
It is conceivable to reduce the size of the image data by compressing the read image. However, if the size of image data is reduced by reducing the resolution of a non-character image (for example, a photograph or a line drawing), the contents of the image may not be recognized.

  The main advantage of the present invention is to reduce the data size while preventing the contents of image data including non-character images from being unrecognizable.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples.

[Application Example 1]
An image processing apparatus,
By analyzing the target image data representing the target image, which is the image data generated by the image reading device, the character region that represents the character and the non-character image that is a non-character image that is a non-character image A detection unit for detecting a character area;
A character compression unit that generates compressed character image data representing the character by compressing a portion representing the character region of the target image data;
By using the target image data, a non-character image data representing the non-character image of the non-character region is acquired, and a storage unit that stores the acquired non-character image data in a storage unit;
Data that generates output image data that includes the compressed character image data and storage destination data that represents storage destination information that is information indicating the storage destination of the non-character image data, and does not include the non-character image data. A generator,
An image processing apparatus comprising:

  According to this configuration, it is possible to use a non-character image by using the storage destination information, express characters in the character area by using the output image data, and the size of the output image data to be generated Compared with image data, it can be made smaller.

[Application Example 2]
The image processing apparatus according to Application Example 1,
A non-character compression unit that generates compressed non-character image data representing the non-character image by compressing a portion representing the non-character area of the target image data;
The data generation unit generates the output image data including the compressed non-character image data;
Image processing device.

  According to this configuration, the size of the output image data representing the non-character image can be made smaller than the target image data.

[Application Example 3]
An image processing apparatus according to Application Example 2,
The data generator is
Evaluate the degree of image quality degradation due to the compression of the non-character image,
When the result of the evaluation is within an allowable range, the output image data including the compressed character image data and the compressed non-character image data and not including the storage destination data is generated. ,
When the result of the evaluation is outside the allowable range, the output image data including the compressed character image data, the compressed non-character image data, and the storage destination data is generated.
Image processing device.

  According to this configuration, when the evaluation result of the degree of image quality degradation due to the compression of the non-character image is within the allowable range, the non-character image can be used by using the compressed non-character image data, The data size of the output image data can be reduced. If the evaluation result is out of the allowable range, the non-character image data specified by the storage destination information is used, the non-character image can be used, and the compressed non-character image data is used for output. The data size of the image data can be reduced.

[Application Example 4]
The image processing apparatus according to any one of Application Examples 1 to 3,
The image processing apparatus, wherein the storage destination information is a symbol image representing the encoded storage destination.

  According to this configuration, the image size of the image used as the storage destination information can be reduced.

[Application Example 5]
The image processing apparatus according to any one of Application Examples 1 to 4,
The image processing apparatus, wherein the storage destination information is an image representing the storage destination, and is arranged at a position where at least a part of the storage destination information overlaps an area corresponding to the non-character area.

  According to this configuration, the difference between the target image and the image represented by the output image data is reduced as compared with the case where the storage destination information is arranged at a position away from the area corresponding to the non-character area. can do.

[Application Example 6]
An image reading device for generating the target image data;
The image processing device according to any one of Application Examples 1 to 5,
An image processing system comprising:

[Application Example 7]
A computer program,
By analyzing the target image data representing the target image, which is the image data generated by the image reading device, the character region that represents the character and the non-character image that is a non-character image that is a non-character image A detection function for detecting a character area;
A character compression function for generating compressed character image data representing the character by compressing a portion representing the character region of the target image data;
By using the target image data, a non-character image data representing the non-character image of the non-character region is acquired, and a storage function for storing the acquired non-character image data in a storage unit;
Data that generates output image data that includes the compressed character image data and storage destination data that represents storage destination information that is information indicating the storage destination of the non-character image data, and does not include the non-character image data. Generation function,
A program that makes a computer realize.

  The present invention can be realized in various forms, for example, an image processing method and an image processing apparatus, a computer program for realizing the function of the method or apparatus, and a recording in which the computer program is recorded. It can be realized in the form of a medium (for example, a recording medium that is not temporary).

It is explanatory drawing which shows the network system as one Example of this invention. It is a flowchart of an image process. It is the schematic of image processing. It is a flowchart of the production | generation process of storage destination data. It is a flowchart which shows another Example of an image process.

A. First embodiment:
FIG. 1 is an explanatory diagram showing a network system as an embodiment of the present invention. The network system 1000 includes a network 900, an image processing system 800 connected to the network 900, and a server 400 connected to the network 900. The image processing system 800 includes an image processing apparatus 100 connected to a network 900 and a scanner 300 connected to the image processing apparatus 100.

  The image processing apparatus 100 is, for example, a so-called personal computer. The image processing apparatus 100 includes a CPU 110, a volatile storage device 120, a nonvolatile storage device 130, a display unit 140, an operation unit 150, a device interface 160, and a communication interface 170.

  The volatile storage device 120 is, for example, a so-called DRAM, and the nonvolatile storage device 130 is, for example, a so-called flash memory. The non-volatile storage device 130 stores a program 132 executed by the CPU 110. The CPU 110 implements various functions by executing the program 132. In the present embodiment, the CPU 110 includes a target data acquisition unit 210, a detection unit 220, a character compression unit 230, a non-character compression unit 240, a non-character storage unit 250, an output data generation unit 260, and a scanner control unit. 270 and the functions of the respective processing units. Details of each processing unit will be described later. In addition, the CPU 110 temporarily stores various intermediate data used for executing the program (for example, the program 132) in a storage device (for example, the volatile storage device 120 or the nonvolatile storage device 130). .

  The display unit 140 is a device that displays an image, and is, for example, a liquid crystal display. The operation unit 150 is a device that accepts an operation by a user, and is, for example, a touch panel arranged on the display unit 140. The user can input various instructions such as an image processing instruction by operating the operation unit 150. The device interface 160 is an interface for communicating with another device different from the image processing device 100, and is, for example, a USB interface. A scanner 300 is connected to the device interface 160. The communication interface 170 is an interface for connecting to a network, and is, for example, a wireless interface according to the IEEE802.11a / b / g / n standard. The communication interface 170 is connected to the network 900.

  The scanner 300 is an apparatus that generates image data (also referred to as “scan data”) representing an object by optically reading the object such as a document. The scanner 300 includes a control device 310 and a reading mechanism 320 that optically reads an object and generates scan data. The control device 310 is a computer having a CPU, a volatile storage device, a nonvolatile storage device, and a device interface (not shown). The control device 310 is connected to the device interface 160 of the image processing device 100. The control device 310 controls the operation of the scanner 300 by executing a program stored in the volatile storage device. For example, the control device 310 receives an instruction from the image processing apparatus 100, controls the reading mechanism 320 according to the received instruction, generates scan data, and supplies the generated scan data to the image processing apparatus 100.

  The server 400 includes a control device 410, a nonvolatile storage device 430, and a communication interface 470. The nonvolatile storage device 430 is, for example, a hard disk drive. The communication interface 470 is an interface for connecting to a network, and is, for example, a wired interface conforming to the IEEE 802.3 standard. The communication interface 470 is connected to the network 900. The control device 410 is a computer having a CPU, a volatile storage device, and a nonvolatile storage device (not shown). The control device 410 controls the operation of the server 400 by executing a program stored in a non-volatile storage device (not shown). For example, the control device 410 stores data received from the image processing device 100 in the nonvolatile storage device 430. In response to a request received via the network 900, the control device 410 provides the data stored in the nonvolatile storage device 430 to the requesting device.

  FIG. 2 is a flowchart of image processing. In this image processing, output image data having a smaller size is generated using the scan data generated by the scanner 300. In this embodiment, PDF (Portable Document Format) data is generated as output image data. This image processing is started by the CPU 110 of the image processing apparatus 100 when, for example, the user instructs the image processing apparatus 100 to start image processing. In this embodiment, the user can input an image processing start instruction by operating the operation unit 150.

  In first step S <b> 100, the scanner control unit 270 (FIG. 1) transmits a scan processing execution instruction to the scanner 300. It is assumed that the user has set a scanning object on a document table (for example, a flat bed) (not shown) of the scanner 300 in advance.

  The control device 310 of the scanner 300 drives the reading mechanism 320 in accordance with the instruction, and generates scan data representing the object. The generated scan data is, for example, RGB bitmap data. The control device 310 transmits the generated scan data to the image processing device 100, and the scanner control unit 270 of the image processing device 100 receives the scan data. The target data acquisition unit 210 acquires scan data as target image data for image processing through the scanner control unit 270. Hereinafter, an image represented by target image data (that is, scan data) is also referred to as a “target image”.

  FIG. 3 is a schematic diagram of image processing. In the figure, an outline of processing for generating an output image OI1 from the target image TI1 according to the procedure of FIG. 2 is shown. In the example of FIG. 3, the target image TI1 represents a photographic image Op1 and four character string images Ot1 to Ot4. In FIG. 3, processes corresponding to the processes shown in FIG. For example, the process denoted by “S110” in FIG. 3 corresponds to the process of step S110 in FIG.

  In the next step S110 of FIG. 2, the detection unit 220 analyzes the target image data to obtain a character region that is a region representing characters and a non-character image that is an image other than characters (for example, a photograph or a line drawing). A non-character region that is a region to represent is detected. In the example of FIG. 3, a photographic area Op1a representing the photographic image Op1 and four character areas Ot1a to Ot4a representing the four character string images Ot1 to Ot4, respectively, are detected.

  As a method for detecting a character area and a non-character area from the target image, various known methods can be employed. For example, the target image is divided into a plurality of processing regions (for example, rectangular regions of a predetermined size), the variance of pixel values (for example, luminance values) is calculated for each processing region, and the processing region has a variance smaller than a predetermined threshold Are classified into character processing areas, and processing areas whose variance is greater than or equal to a threshold are classified as non-character processing areas. Then, one continuous area constituted by continuous processing areas of the same type is extracted as one area (that is, a character area or a non-character area). Note that the detection of the area is not limited to the dispersion, and various other information (for example, the number of colors used in each processing area) can be employed. Further, the detection unit 220 may detect a character region by using a character recognition process used in a known OCR (Optical Character Recognition) technique. The detection unit 220 may detect a character area and a non-character area by combining a plurality of pieces of information.

  In the next step S120 in FIG. 2, the output data generation unit 260 selects an unprocessed non-character area as a target area from the areas detected in step S110. In the next step S130, the non-character storage unit 250 extracts a portion representing the target area (here, the non-character area) from the target image data, and uses the extracted image data to represent the image data representing the non-character area. A file is generated (hereinafter also referred to as “non-character image file”). In the present embodiment, the non-character storage unit 250 acquires compressed image data by compressing the extracted image data (for example, JPEG compression), and generates an image data file including the acquired compressed image data. . Instead, the non-character storage unit 250 may generate an image data file that directly includes the extracted image data.

  In the next step S <b> 140, the non-character storage unit 250 transmits the generated non-character image file to the server 400 and stores it in the nonvolatile storage device 430 of the server 400. The control device 410 of the server 400 stores the received non-character image file in the nonvolatile storage device 430 (FIG. 1: non-character image file 434). Note that the storage destination of the non-character image file (for example, URL) is determined by the non-character storage unit 250. The control device 410 of the server 400 stores the non-character image file in the nonvolatile storage device 430 according to the storage destination specified by the non-character storage unit 250. Instead, the control device 410 of the server 400 may determine the storage destination.

  In the next step S150, storage destination data representing a storage destination image that is an image representing the storage destination of the non-character image file 434 stored in the nonvolatile storage device 430 of the server 400 is generated. FIG. 4 is a flowchart of storage destination data generation processing. In the first step S300, the output data generation unit 260 acquires the storage destination of the non-character image file. In this embodiment, a URL is used as the storage destination. The output data generation unit 260 acquires the storage destination from the non-character storage unit 250. When the storage destination is determined by the control device 410 of the server 400, the output data generation unit 260 acquires the storage destination from the control device 410.

  In the next step S310, the output data generation unit 260 generates storage destination data that represents a storage destination image that represents the acquired storage destination. In the present embodiment, the storage destination data represents a QR code (“QR code” is a registered trademark) representing the encoded storage destination. When the generation of the storage destination data is completed, the process of FIG. 4 ends.

  In the next step S160 of FIG. 2, the output data generation unit 260 incorporates the generated storage destination data into the output image data. FIG. 3 shows an example of the output image OI1 represented by the output image data. As illustrated, the output image OI1 is an image having the same size and shape as the target image TI1. The output image OI1 includes regions Op1ax and Ot1ax to Ot4ax corresponding to the regions Op1a and Ot1a to Ot4a detected from the target image TI1. The size, position, and shape of each region Op1ax, Ot1ax to Ot4ax are the same as those of the original region Op1a, Ot1a to Ot4a. The image in each area of the output image OI1 can be corrected from the image in the corresponding area of the target image TI1. For example, a QR code Si1 represented by storage destination data is arranged in the photographic area Op1ax of the output image OI1. This QR code Si1 represents a URL for accessing a non-character image file stored in the server 400, that is, image data representing the photo image Op1 arranged in the corresponding photo area Op1a in the target image TI1. Yes.

  In the next step S170 in FIG. 2, the non-character compressing unit 240 extracts a portion representing the target area (here, the non-character area) from the target image data, and compresses the extracted image data to compress the extracted image data. Non-character image data is generated. In this embodiment, as shown in FIG. 3, the non-character compression unit 240 generates compressed non-character image data by performing JPEG compression and further performing Flate compression.

  In this step S170, the image data is compressed at a higher compression rate than in step S130. Therefore, the data size of the compressed non-character image data generated in step S170 is smaller than the data size of the image data (non-character image file) generated in step S130.

  In the next step S180 of FIG. 2, the output data generation unit 260 incorporates the compressed non-character image data generated in step S170 into the output image data. As shown in FIG. 3, a photographic image Op1x represented by compressed non-character image data is arranged in the photographic area Op1ax of the output image OI1. This photographic image Op1x is approximately the same as the original photographic image Op1 (the photographic image Op1x may contain noise due to data compression). The QR code Si1 is disposed on the photographic image Op1x. That is, a part of the photographic image Op1x is hidden in the QR code Si1.

  In the next step S190 in FIG. 2, the output data generation unit 260 determines whether or not the processing for all the non-character areas has been completed. If an unprocessed non-character area remains (S190: No), the process returns to step S120. When the processing for all the non-character areas is completed (S190: Yes), the processing moves to step S200.

  In step S200, the character compression unit 230 extracts a portion representing a character region from the target image data, and generates compressed character image data by compressing the extracted image data. In the present embodiment, as shown in FIG. 3, the character compression unit 230 performs binarization processing, and further performs binary compression (for example, MMR (Modified Modified Read) compression (also referred to as FAXG4 method)). By doing so, compressed character image data is generated. Various known methods can be adopted as the binarization method. For example, each pixel may be binarized by calculating a luminance value from a pixel value (RGB value) included in the target image data and applying a predetermined threshold to the luminance value. Note that the generation of compressed character image data is performed for each of all character regions detected in step S110.

  In the next step S210, the output data generation unit 260 incorporates the generated compressed character image data into the output image data. As shown in FIG. 3, character string images Ot1x to Ot4x represented by compressed character image data are arranged in the character areas Ot1ax to Ot4ax of the output image OI1. The character string images Ot1x to Ot4x are approximately the same as the original character string images Ot1 to Ot4, respectively (the character string images Ot1x to Ot4x may include noise due to data compression).

  Thus, the generation of output image data is completed. In the next step S <b> 220, the output data generation unit 260 stores the generated output image data in the nonvolatile storage device 130. Thus, the image processing ends. The user can use the output image data stored in the nonvolatile storage device 130 for output such as printing and display, and for various other purposes.

  As described above, in this embodiment, the non-character storage unit 250 acquires non-character image data (non-character image file image data) representing a non-character image in a non-character area by using the target image data. (FIG. 2: S130), the acquired non-character image data is stored in the nonvolatile storage device 430 of the server 400 (FIG. 2: S140). On the other hand, the output data generation unit 260 includes the compressed character image data generated by the character compression unit 230 (FIG. 2: S200, S210), storage destination data representing a QR code representing the storage destination of non-character image data ( FIG. 2: 160), and output image data that does not include the non-character image data (image data of the non-character image file) is generated. Accordingly, it is possible to use a non-character image (for example, photographic image Op1) by using a QR code (for example, recognition of the contents of the non-character image), and to express a character string in a character region by using output image data. Furthermore, the size of the output image data can be reduced as compared with the target image data. For example, the user can easily use the non-character image file 434 stored in the nonvolatile storage device 430 of the server 400 by photographing the output image OI1 using a mobile phone having a function of analyzing a QR code. Can do.

  Further, the non-character compressing unit 240 generates compressed non-character image data by compressing a portion representing the non-character area in the target image data (FIG. 2: S170), and the output data generating unit 260 Output image data including compressed non-character image data is generated (FIG. 2: S180). Therefore, the data size of the output image data representing the non-character image can be made smaller than the target image data. Further, the user can recognize the non-character image by observing the output image represented by the output image data. Further, when the content of the non-character image cannot be sufficiently visually recognized, the non-character image stored in the non-volatile storage device 430 of the server 400 is less deteriorated than the non-character image represented by the output image data by using the QR code. A character image file may be used.

  Further, in step S310 of FIG. 4, the encoded QR code representing the storage destination is generated as an image representing the storage destination. Therefore, the image size of the storage destination image can be reduced as compared with the case where the storage destination is expressed by a character string. As a result, the storage destination image (here, the QR code) can be easily arranged in the corresponding non-character region in the output image. For example, as shown in FIG. 3, the storage destination image (QR code Si1) can be arranged in the photographic area Op1ax. As a result, the difference between the target image and the output image can be reduced as compared with the case where the storage destination image is arranged outside the corresponding non-character region. Further, the user can easily understand the correspondence between the storage destination image and the non-character image by observing the output image. Even when the output image is output by printing, the non-character image file stored in the nonvolatile storage device 430 of the server 400 can be easily used by using the storage destination image.

B. Second embodiment:
FIG. 5 is a flowchart showing another embodiment of image processing. The process of FIG. 5 is used instead of the process of FIG. In the second embodiment, whether to save the non-character image file in the nonvolatile storage device 430 of the server 400 is determined according to the evaluation result of the degree of image quality degradation when the non-character image is compressed. In FIG. 5, the same steps as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted. The configuration of the network system used for executing the image processing is the same as the configuration of the network system 1000 shown in FIG.

  Steps S100 to S130 are the same as steps S100 to S130 of FIG. In the next step S132, the output data generation unit 260 (FIG. 1) evaluates the degree of deterioration in image quality of the non-character image due to data compression by the non-character compression unit 240. In the present embodiment, the output data generation unit 260 calculates the edge amount at each pixel position of the non-character image, and calculates the average value of the obtained edge amounts as an evaluation value representing the degree of image quality degradation. The edge amount is obtained by calculating a luminance value from a pixel value (RGB value) included in the target image data and applying a known sobel filter to the luminance value. In addition, not only a Sobel filter but various edge extraction filters, such as a Prewitt filter and a Roberts filter, can be used.

  A small average edge amount indicates that a change in pixel value with respect to a change in pixel position in the non-character image is small. When the change in pixel value is small, noise due to data compression is often small. On the other hand, a large average edge amount indicates a large change in pixel value with respect to a change in pixel position in the non-character image. When the change in the pixel value is large, noise due to data compression is often large. As described above, the smaller the average edge amount, the smaller the degree of image quality degradation.

  In the next step S134 in FIG. 5, the output data generation unit 260 determines whether or not the average edge amount is larger than a predetermined threshold value. In the present embodiment, a range that is equal to or smaller than a predetermined threshold corresponds to an allowable range. When the average edge amount is outside the allowable range, that is, when the average edge amount is larger than the predetermined threshold (S134: Yes), the processes of steps S140 to S160 are executed. Steps S140 to S160 are the same as steps S140 to S160 in FIG. Specifically, the non-character image file is stored in the nonvolatile storage device 430 of the server 400, and the storage destination data is incorporated into the output image data. Then, the process proceeds to step S170. On the other hand, when the average edge amount is within the allowable range (S134: No), the processes in steps S140 to S160 are omitted, and the process proceeds to step S170. The processes after step S170 (S170 to S220) are performed in the same manner as in FIG.

  As described above, when the average edge amount is within the allowable range, the output data generation unit 260 includes the compressed character image data (S200, S210), the compressed non-character image data (S170, S180), And output image data including no storage destination data. Therefore, by using the compressed non-character image data, the data size of the output image data can be reduced while making the non-character image available. In addition, since the storage of the non-character image file in the nonvolatile storage device 430 of the server 400 is omitted, the capacity of the nonvolatile storage device 430 can be saved. Further, since the output image does not include the save destination image, the non-character image area is not disturbed by the save destination image. On the other hand, when the average edge amount is outside the allowable range, the output data generation unit 260 outputs the compressed character image data (S200, S210) and the compressed non-character image data (S170, S210). Output image data including S180) and storage destination data (S150, S160) is generated. Therefore, by using the non-character image data specified by the save destination image (here, the non-character image file specified by the QR code), it is possible to use the non-character image in which the deterioration of the image quality is suppressed, and the compression. By using the finished non-character image data, the data size of the output image data can be reduced. Further, the user can easily know whether or not the non-character image file is stored in the nonvolatile storage device 430 of the server 400 based on whether or not the output destination image includes the storage destination image.

C. Variation:
(1) The method of compressing image data representing characters by the character compression unit 230 is not limited to binarization and MMR, and various methods can be employed. For example, only one of binarization and MMR may be employed. Further, JPEG compression may be adopted. Further, a process for reducing the resolution (pixel density) may be employed. In general, any processing that reduces the data size of the original image data can be employed under the condition that the characters expressed by the image data can be recognized.

(2) The method of compressing image data representing a non-character image by the non-character compression unit 240 is not limited to JPEG compression and Flate compression, and various methods can be employed. For example, only one of JPEG compression and Flate compression may be employed. Further, a process for reducing the resolution (pixel density) may be employed. In general, any process for reducing the data size of the original image data can be employed under the condition that a non-character image represented by the image data can be recognized.

(3) The symbol image representing the encoded storage destination is not limited to the QR code, and various images can be employed. For example, a one-dimensional barcode can be adopted. Further, the storage destination image representing the storage destination is not limited to the symbol image representing the encoded storage destination, and various other types of images can be employed. For example, a character string representing a storage destination can be adopted. Further, the compressed non-character image may be handled as the storage destination image by adding a hyperlink to the compressed non-character image. In this case, the storage destination data and the compressed non-character image data are the same data, and are data in which a hyperlink is embedded as information indicating the storage destination in the compressed non-character image.

  In the output image, the portion of the storage destination image that overlaps the corresponding non-character area may be a part of the storage destination image. In general, if at least a part of the save destination image overlaps with the corresponding non-character area, the save destination image is not between the target image and the output image as compared with the case where the save destination image is separated from the corresponding non-character area. The difference can be reduced. In addition, the user can easily understand the correspondence between the storage destination image and the non-character image. The storage destination image may be arranged at a position away from the non-character area. For example, the storage destination image may be arranged at a predetermined position in the output image.

  In any case, the output data generation unit 260 may generate compressed data as storage destination data representing a storage destination image (for example, JPEG data). As the compression method, for example, the same method as the image data compression method by the character compression unit 230 can be employed. Instead, uncompressed data may be generated as storage destination data (for example, bitmap data).

(4) In the embodiment of FIG. 5, as a method for evaluating the degree of image quality deterioration, a value obtained by using the edge amount as an evaluation value of the degree of image quality deterioration (for example, not only the average edge amount but the total edge amount) For example, it is possible to adopt various methods without being limited to the method of calculating whether or not the calculated evaluation value is within the allowable range. For example, the output data generation unit 260 calculates a difference between pixel values (for example, luminance values) at the same pixel position between the compressed image data and the original image data, and calculates the total value of the obtained differences. You may compare with a predetermined threshold value. In this case, the smaller the total difference, the smaller the degree of image quality degradation. Thus, an evaluation value obtained by using a difference in pixel values at the same pixel position between the compressed image data and the original image data (for example, a representative representing a difference in pixel values such as a total difference or an average difference). Value) and determining whether or not the calculated evaluation value is within an allowable range may be employed. In either case, as the allowable range of the evaluation result, a range indicating that the degree of image quality deterioration is smaller than a predetermined standard can be employed. Such an allowable range can be experimentally determined using various target images.

(5) The procedure of image processing is not limited to the procedure shown in FIGS. 2 and 5, and various procedures can be adopted. For example, steps S170 and S180 may be omitted. In this case, the storage destination image is arranged in the non-character area, and the non-character image is omitted. For example, the QR code Si1 is arranged in the photographic region Op1ax of the output image OI1 in FIG. 3, and the photographic image Op1x is omitted. Steps S120 to S190 may be executed after step S210.

(6) The format of the output image data is not limited to the PDF format, and any other format can be adopted. For example, a PDL (Page Description Language) format such as PostScript (registered trademark) or PDF format can be adopted. Further, not only the PDL format but also other formats such as a bitmap format may be adopted. Further, as the format of the target image data, any format that can be generated by the scanner 300 can be adopted.

(7) The image reading apparatus is not limited to the scanner 300, and various apparatuses that optically read an image can be used. For example, a digital camera can be employed as the image reading device.

(8) The storage destination of the non-character image data by the non-character storage unit 250 is not limited to a storage device that can communicate through the network 900 (for example, the nonvolatile storage device 430 of the server 400), and various storage devices can be adopted. It is. For example, a removable memory (not shown, for example, a USB flash memory) connected to the image processing apparatus 100 may be employed. In this case, a path name representing the storage location of the non-character image data can be adopted as the storage destination.

(9) The configuration of the image processing system is not limited to the configuration shown in FIG. 1, and various configurations can be employed. For example, the image processing apparatus 100 and the scanner 300 may be incorporated into one apparatus (for example, a multifunction peripheral).

(10) Functions for image processing (for example, the processing units 210 to 270 in FIG. 1) may be realized by a device of a different type from a personal computer (for example, a digital camera, a scanner, a mobile phone, or a multifunction device). Good. Further, the scanner and the image processing apparatus may be connected via a network. The network may be wired regardless of wireless, and may be a local area network or a wide area network. In addition, a plurality of devices (for example, computers) that can communicate with each other via a network may share a part of the function for image processing and provide the function for image processing as a whole ( A system including these devices corresponds to an image processing device).

  In each of the above embodiments, a part of the configuration realized by hardware may be replaced with software, and conversely, part or all of the configuration realized by software may be replaced with hardware. Also good. For example, the function of the character compression unit 230 in FIG. 1 may be realized by a dedicated hardware circuit having a logic circuit.

  When a part or all of the functions of the present invention are realized by a computer program, the program is provided in a form stored in a computer-readable recording medium (for example, a non-temporary recording medium). be able to. The program can be used in a state where it is stored in the same or different recording medium (computer-readable recording medium) as provided. The “computer-readable recording medium” is not limited to a portable recording medium such as a memory card or a CD-ROM, but is connected to an internal storage device in a computer such as various ROMs or a computer such as a hard disk drive. It also includes an external storage device.

  As mentioned above, although this invention was demonstrated based on the Example and the modification, Embodiment mentioned above is for making an understanding of this invention easy, and does not limit this invention. The present invention can be changed and improved without departing from the spirit and scope of the claims, and equivalents thereof are included in the present invention.

DESCRIPTION OF SYMBOLS 100 ... Image processing apparatus, 110 ... CPU, 120 ... Volatile storage device, 130 ... Nonvolatile storage device, 132 ... Program, 140 ... Display part, 150 ... Operation , 160 ... device interface, 170 ... communication interface, 210 ... target data acquisition unit, 220 ... detection unit, 230 ... character compression unit, 240 ... non-character compression unit, 250 ... non-character storage unit, 260 ... output data generation unit, 270 ... scanner control unit, 300 ... scanner, 310 ... control device, 320 ... reading mechanism, 400 ... server , 410 ... Control device, 430 ... Non-volatile storage device, 434 ... Non-character image file, 470 ... Communication interface, 800 ... Image processing system, 900 ... Network, 1000 .. Network system

Claims (7)

An image processing apparatus,
By analyzing the target image data representing the target image, which is the image data generated by the image reading device, the character region that represents the character and the non-character image that is a non-character image that is a non-character image A detection unit for detecting a character area;
A character compression unit that generates compressed character image data representing the character by compressing a portion representing the character region of the target image data;
By using the target image data, a non-character image data representing the non-character image of the non-character region is acquired, and a storage unit that stores the acquired non-character image data in a storage unit;
Data that generates output image data that includes the compressed character image data and storage destination data that represents storage destination information that is information indicating the storage destination of the non-character image data, and does not include the non-character image data. A generator,
An image processing apparatus comprising: The image processing apparatus according to claim 1, further comprising:
A non-character compression unit that generates compressed non-character image data representing the non-character image by compressing a portion representing the non-character area of the target image data;
The data generation unit generates the output image data including the compressed non-character image data;
Image processing device. The image processing apparatus according to claim 2,
The data generator is
Evaluate the degree of image quality degradation due to the compression of the non-character image,
When the result of the evaluation is within an allowable range, the output image data including the compressed character image data and the compressed non-character image data and not including the storage destination data is generated. ,
When the result of the evaluation is outside the allowable range, the output image data including the compressed character image data, the compressed non-character image data, and the storage destination data is generated.
Image processing device. The image processing apparatus according to any one of claims 1 to 3,
The image processing apparatus, wherein the storage destination information is a symbol image representing the encoded storage destination. The image processing apparatus according to any one of claims 1 to 4,
The image processing apparatus, wherein the storage destination information is an image representing the storage destination, and is arranged at a position where at least a part of the storage destination information overlaps an area corresponding to the non-character area. An image reading device for generating the target image data;
An image processing apparatus according to any one of claims 1 to 5,
An image processing system comprising: A computer program,
By analyzing the target image data representing the target image, which is the image data generated by the image reading device, the character region that represents the character and the non-character image that is a non-character image that is a non-character image A detection function for detecting a character area;
A character compression function for generating compressed character image data representing the character by compressing a portion representing the character region of the target image data;
By using the target image data, a non-character image data representing the non-character image of the non-character region is acquired, and a storage function for storing the acquired non-character image data in a storage unit;
Data that generates output image data that includes the compressed character image data and storage destination data that represents storage destination information that is information indicating the storage destination of the non-character image data, and does not include the non-character image data. Generation function,
A program that makes a computer realize.

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