JP2016048828A - Information processing device, information processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processing device, an information processing method, and a program capable of correcting the distribution of the brightness of pixels included in a color image.SOLUTION: The information processing device comprises: a brightness image generator which generates a brightness image on the basis of a color image; a brightness image corrector which corrects the pixel values of pixels included in the generated brightness image; and a color image corrector which corrects the color component of pixels included in the color image, on the basis of a result of the correction by the brightness image corrector.SELECTED DRAWING: Figure 9

Description

  The present invention relates to an information processing apparatus, an information processing method, and a program.

  Conventionally, various techniques for correcting the image quality of image data read by an image pickup device such as a CCD (Charge Coupled Device) have been developed.

  For example, Patent Document 1 discloses that the density of the background color of a form is detected based on the frequency distribution of the luminance of the pixel for grayscale image data of the form read by the CCD sensor, and the detected form of the form is detected. A technique for correcting the luminance of each pixel so that the density of the ground color matches the reference luminance is described.

  Further, in Patent Document 2, in order to correct an error due to shading distortion of a pixel signal by each CCD element constituting the CCD, correction is made so that the black level and the white level of the pixel signal by each CCD element are uniform. The technology is described.

  Japanese Patent Application Laid-Open No. 2004-228561 describes a technique for matching each average value of output voltages of RGB channels output from a CCD line sensor to a predetermined voltage.

JP 2002-15313 A Japanese Patent Laid-Open No. 8-18779 JP-A-9-37086

  As described above, the technique described in Patent Document 1 is a technique for correcting the distribution of pixel values of pixels included in a grayscale image. On the other hand, a color image has a plurality of color components. Therefore, the technique described in Patent Document 1 cannot be directly applied to a color image.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is a new and improved technique capable of correcting the brightness distribution of pixels included in a color image. An information processing apparatus, an information processing method, and a program are provided.

  In order to solve the above-described problem, according to an aspect of the present invention, a brightness image generation unit that generates a brightness image based on a color image, and a brightness image that corrects pixel values of pixels included in the generated brightness image An information processing apparatus is provided that includes: a correction unit; and a color image correction unit that corrects a color component of a pixel included in the color image based on a result of correction by the brightness image correction unit.

  The brightness image may be a grayscale image corresponding to a pixel value of a pixel included in the color image.

  The pixel value of the first pixel included in the brightness image may be a pixel value of a color component having the largest pixel value among a plurality of color components of the pixel corresponding to the first pixel in the color image. .

  The color image correction unit is configured to generate the color based on a ratio between a pixel value of a first pixel included in the generated brightness image and a pixel value of the first pixel corrected by the brightness image correction unit. The color component of the pixel corresponding to the first pixel in the image may be corrected.

  The color image correction unit corresponds to a ratio of a pixel value of the first pixel after correction to a pixel value of the first pixel included in the generated brightness image, corresponding to the first pixel in the color image. The color component of the pixel corresponding to the first pixel in the color image may be corrected by multiplying the color component of the pixel to be corrected.

  The brightness image correction unit may correct the pixel values of the first pixels included in the generated brightness image based on the pixel values of a plurality of pixels around the first pixels.

  The brightness image correction unit may further correct the pixel value of the first pixel based on distances between a plurality of pixels around the first pixel.

  The color components of the pixels included in the color image may be RGB color components of the pixels included in the color image.

  In order to solve the above problem, according to another aspect of the present invention, a step of generating a brightness image based on a color image, and a step of correcting pixel values of pixels included in the generated brightness image, And a step of correcting a color component of a pixel included in the color image based on the result of the correction.

  In order to solve the above-described problem, according to another aspect of the present invention, a computer includes a brightness image generation unit that generates a brightness image based on a color image, and pixels of pixels included in the generated brightness image. A program is provided for functioning as a brightness image correction unit that corrects a value, and a color image correction unit that corrects a color component of a pixel included in the color image based on a correction result by the brightness image correction unit. Is done.

  As described above, according to the present invention, the distribution of brightness of pixels included in a color image can be corrected.

It is explanatory drawing which showed the structural example of the information processing system by embodiment of this invention. It is a functional block diagram showing the composition of information processor 10 by the embodiment. It is explanatory drawing which showed the generation example of the brightness image by the same embodiment. It is the graph which showed an example of the frequency distribution of the pixel value of the brightness image before correction by the embodiment. It is the graph which showed an example of frequency distribution of the pixel value of the brightness image after amendment by the embodiment. It is explanatory drawing which showed the example of correction | amendment of the pixel value of the brightness image by the embodiment. It is explanatory drawing which showed the structural example of the block image table by the embodiment. It is explanatory drawing which showed the example of correction | amendment of the pixel value of the color image by the embodiment. It is the flowchart which showed the operation | movement by the embodiment. It is explanatory drawing which showed the hardware constitutions of the information processing apparatus 10 by the embodiment.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  In the present specification and drawings, a plurality of components having substantially the same functional configuration may be distinguished by adding different alphabets after the same reference numeral. For example, a plurality of configurations having substantially the same functional configuration are distinguished as pixel 300a and pixel 300b as necessary. However, when it is not necessary to particularly distinguish each of a plurality of constituent elements having substantially the same functional configuration, only the same reference numerals are given. For example, when it is not necessary to distinguish between the pixel 300a and the pixel 300b, they are simply referred to as the pixel 300.

Further, the “DETAILED DESCRIPTION OF THE INVENTION” will be described according to the following item order.
1. Background 2 2. Detailed description of embodiments 2-1. Information processing system 2-2. Configuration 2-3. Operation 2-4. Effect 3. Hardware configuration Modified example

<< 1. Background >>
The present invention can be implemented in various forms as will be described in detail in “2. Detailed Description of Embodiments” as an example. First, in order to clearly show the features of the present invention, the background that led to the creation of the information processing apparatus according to the present invention will be described.

  Conventionally, various techniques for correcting pixel values of pixels included in a grayscale image have been developed. For example, a technique has been developed in which shadow correction is performed on an area where the brightness of pixels included in image data is low based on the pixel values of pixels in the surrounding area. The pixel value is a value obtained by quantizing light intensity such as reflected light from an object at the position of each pixel by the image sensor. The pixel value is expressed in 256 levels from 0 to 255, for example.

  By the way, the gray scale image has only one color component, whereas the color image has a plurality of color components such as RGB. Therefore, the above-described shadow correction technique cannot be directly applied to a color image. Therefore, in order to apply the above-described shadow correction technique, it is necessary to convert a plurality of color components into one component. As an example of the conversion method, for example, a conversion method by calculating an average value of a plurality of color components, or a conversion method by calculating an average value of a maximum value and a minimum value among a plurality of color components can be considered. .

  However, if these conversion methods are applied to a color image and shadow correction is performed, the corrected value of any color component is larger than an upper limit value such as 255, that is, saturated. There is a risk that.

  Therefore, the information processing apparatus according to the present invention has been created by focusing on the above circumstances. The information processing apparatus according to the present invention can appropriately correct the distribution of brightness of pixels included in a color image. Hereinafter, such embodiments of the present invention will be sequentially described in detail.

<< 2. Detailed Description of Embodiment >>
<2-1. Configuration of information processing system>
First, the configuration of the information processing system according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, the information processing system according to the present embodiment includes an information processing apparatus 10, a scanner 20, and a communication network 22.

[2-1-1. Information processing apparatus 10]
The information processing apparatus 10 is an apparatus for performing image processing on a color image. For example, the information processing apparatus 10 can perform a shadow correction process on a color image received from a scanner 20 described later. Further, the information processing apparatus 10 can recognize characters included in an image by OCR (Optical Character Recognition). The information processing apparatus 10 may be, for example, a PC (Personal Computer) or a server.

[2-1-2. Scanner 20]
The scanner 20 is an apparatus for optically reading a paper medium and recording it as a digital still image. For example, the scanner 20 records the paper medium as a digital image by shining light on the paper medium and converting the reflected light into an electrical signal by the image sensor. As shown in FIG. 1, the scanner 20 may be a non-contact type, for example.

[2-1-3. Communication network 22]
The communication network 22 is a wired or wireless transmission path for information transmitted from a device connected to the communication network 22. For example, the communication network 22 includes a public line network such as a telephone line network, the Internet, and a satellite communication network, various LANs (Local Area Network) including Ethernet (registered trademark), a WAN (Wide Area Network), and the like. The communication network 22 may include a dedicated line network such as an IP-VPN (Internet Protocol-Virtual Private Network).

<2-2. Configuration>
The configuration of the information processing system according to this embodiment has been described above. Next, the configuration of the information processing apparatus 10 according to the present embodiment will be described with reference to FIG. As illustrated in FIG. 2, the information processing apparatus 10 includes a control unit 100, a communication unit 120, and a storage unit 122.

[2-2-1. Control unit 100]
The control unit 100 generally controls the operation of the information processing apparatus 10 using hardware such as a CPU (Central Processing Unit) 150 and a RAM (Random Access Memory) 154, which will be described later, built in the information processing apparatus 10. To do. As shown in FIG. 2, the control unit 100 includes a brightness image generation unit 102, a brightness image correction unit 104, a color image correction unit 106, an OCR image generation unit 108, and an OCR processing unit 110.

[2-2-2. Lightness image generation unit 102]
The lightness image generation unit 102 generates a grayscale lightness image based on a color image received by the communication unit 120 described later. Here, the brightness is an index indicating the brightness of the color of each pixel, and may be synonymous with the brightness defined in the Munsell color system, for example. The brightness is expressed in 256 levels from 0 to 255, for example.

  More specifically, for each pixel of the color image, the brightness image generation unit 102 sets a value corresponding to the pixel value of each RGB component of the pixel to the pixel value of the pixel at the same position in the brightness image. Thus, a brightness image is generated. For example, the brightness image generation unit 102 sets, for each pixel of the color image, the largest pixel value among the pixel values of the RGB color components of the pixel as the pixel value of the pixel at the same position in the brightness image. Generate a brightness image.

  Here, the above function will be described in more detail with reference to FIG. FIG. 3 is an explanatory view showing an example of generation of a brightness image by the brightness image generation unit 102. In FIG. 3, an example in which the color image 30 includes only four pixels 300 is simply illustrated. In FIG. 3, the pixel values of the RGB color components of each pixel 300 are indicated by numerals. For example, the pixel value of the R component in the pixel 300a is “100”, the pixel value of the G component is “20”, and the pixel value of the B component is “80”.

  As illustrated in FIG. 3, the lightness image generation unit 102 sets “100”, which is the largest pixel value among the pixel values of the RGB color components in the pixel 300 a, to a pixel (position is the same) in the lightness image 40. The pixel value is set to 400a.

[2-2-3. Brightness Image Correction Unit 104]
The lightness image correction unit 104 performs pixel value correction processing on the lightness image generated by the lightness image generation unit 102. More specifically, the lightness image correction unit 104 corrects the pixel value of each pixel of the generated lightness image based on the pixel values of a plurality of pixels around the pixel. For example, the lightness image correction unit 104 corrects the pixel value of each pixel of the generated lightness image by a method substantially similar to the method described in JP-A-2002-15313 as described below.

(2-2-3-1. Correction Example 1)
For example, the lightness image correction unit 104 detects the pixel value of the ground color of the form (hereinafter also referred to as P) based on the frequency distribution of pixel values in the generated lightness image, and the pixel value of each pixel and P The pixel value of each pixel is corrected based on the ratio.

  Here, the above function will be described in more detail. FIG. 4 is a graph showing a frequency distribution of pixel values of each pixel included in the brightness image before correction. As shown in FIG. 4, the lightness image correction unit 104 first detects as P a pixel value that is close to the white level and has the highest frequency. Then, the lightness image correction unit 104 corrects the pixel value (hereinafter also referred to as k) of each pixel as follows according to the size of the pixel value of each pixel of the lightness image before correction.

When -k ≦ P When the value of k is included in the above range, the brightness image correction unit 104 first sets the ratio of k and P (= k / P) for each pixel, for example, linear correction or Convert by gamma correction. Then, the lightness image correcting unit 104 corrects the value of k by multiplying the converted value by a reference pixel value (hereinafter also referred to as M). Note that M is a predetermined value such as “230”.

When −P <k ≦ 255−M + P Also, when the value of k is included in the above range, the lightness image correction unit 104 adds (M−P) to k, so that k Correct the value. That is, when the pixel value of each pixel after correction is set to K, the brightness image correction unit 104 performs correction according to the following mathematical formula.
K = k + MP

-K> 255-M + P When the value of k is included in the above range, the lightness image correction unit 104 corrects the value of k uniformly to “255”, that is, the upper limit value.

  According to this correction example 1, the frequency distribution of the pixel values of the brightness image shown in FIG. 4 is set so that the pixel value of a pixel whose pixel value is P is M, for example, as in the graph shown in FIG. It is corrected. That is, the pixel value distribution of the brightness image can be corrected to be increased to a predetermined level.

(2-2-3-2. Correction Example 2)
Alternatively, the brightness image correction unit 104, for each pixel in the brightness image before correction, based on the pixel values of the plurality of pixels around the pixel and the distance between the pixel and each of the plurality of pixels. The pixel value of the pixel is corrected.

  For example, the lightness image correction unit 104 first divides the generated lightness image into rectangular image blocks each having m (for example, 100) pixels and n (for example, 100) pixels. Then, the brightness image correction unit 104 associates the maximum pixel value among the pixel values of the pixels included in each divided image block with the center coordinates (X, Y) of each image block, and a block image described later. Record in table 124. Thereby, the maximum pixel value among the pixel values of the pixels included in each image block is set as the pixel value of the center coordinates of each image block.

  Then, the brightness image correction unit 104 sets, for each pixel in the brightness image before correction, for example, center coordinates P1, P2, P3, and P4 of four image blocks surrounding the pixel as shown in FIG. Based on the calculated pixel value and the ratio of the distance between the pixel and each of these four points, the pixel value of the pixel is corrected by, for example, Equation 1 below.

  As shown in FIG. 6, Xa in Equation 1 above is the x coordinate value of P1 and P2, Xb is the x coordinate value of P3 and P4, and Ya is the y coordinate value of P1 and P3. Yb is the y coordinate value of P2 and P4.

  FIG. 7 is an explanatory diagram showing a configuration example of the block image table 124. As shown in FIG. 7, in the block image table 124, for example, block No. 1240, center coordinates 1242, and pixel value 1244 are recorded in association with each other. Here, in block No. 1240, an identification number for distinguishing each image block divided from the brightness image is recorded. In the center coordinate 1242, the coordinate value of the center of the image block corresponding to the block No. 1240 is recorded. In the pixel value 1244, the maximum pixel value among the pixel values of the pixels included in the image block corresponding to the block No. 1240 is recorded. Note that, as described above, the pixel value 1244 is set as the pixel value of the pixel having the coordinate value of the center coordinate 1242.

  According to this correction example 2, the pixels included in each image block are pixels with a correction amount corresponding to the distance between the image blocks around the pixel and the (maximum) pixel value difference between the image blocks. The value is corrected. For this reason, for example, a local shadow can be smoothly corrected so as to be natural to the eye.

  As a modification, the lightness image correction unit 104 can correct each pixel of the generated lightness image by combining the correction example 1 and the correction example 2. For example, the lightness image correction unit 104 may first correct each pixel of the generated lightness image according to the correction example 2, and then further correct the lightness image after correction according to the correction example 1. .

[2-2-4. Color image correction unit 106]
For each pixel of the received color image, the color image correction unit 106 has the pixel value of the same pixel in the brightness image generated by the brightness image generation unit 102 and the pixel value of the pixel corrected by the brightness image correction unit 104. Based on the ratio, the pixel values of the RGB color components of the pixel in the color image are corrected. For example, the color image correction unit 106 calculates, for each pixel of the color image, the ratio of the pixel value of the pixel in the lightness image after correction to the pixel value of the same pixel in the lightness image before correction, as shown in Equation 2 below. The pixel value of each color component of each pixel is corrected by multiplying the pixel value of each color component of the pixel in the color image.

  In the above formula, the pixel value of each RGB color component of the pixel (i, j) in the color image before correction is described as “R”, “G”, or “B”, and the color after correction The pixel value of each RGB color component of the pixel (i, j) in the image is described as “R ′”, “G ′”, or “B ′”.

  Here, the above function will be described in more detail with reference to FIG. FIG. 8 is an explanatory diagram showing an example of color image correction by the color image correction unit 106. As shown by the pixel 320a in FIG. 8, the color image correction unit 106 sets the pixel value of the R component included in the pixel 300a in the color image 30 before correction to “100 (R component of the pixel 300a) × 120 (correction). "120" is corrected by "pixel value of the pixel 420a of the subsequent brightness image 42) / 100 (pixel value of the pixel 400a of the brightness image 40 before correction)". Similarly, the color image correction unit 106 sets the pixel value of the G component of the pixel 300a to “20 (G component of the pixel 300a) × 120 (pixel value of the pixel 420a) / 100 (pixel value of the pixel 400a)”. 24 ”is corrected. Further, the color image correction unit 106 sets the pixel value of the B component of the pixel 300a to “96 (B component of the pixel 300a) × 120 (pixel value of the pixel 420a) / 100 (pixel value of the pixel 400a)”. To correct.

[2-2-5. OCR image generation unit 108]
The OCR image generation unit 108 generates an OCR image that is a binary image based on the color image corrected by the color image correction unit 106.

  More specifically, the OCR image generation unit 108 first generates a grayscale image based on the color image corrected by the color image correction unit 106. For example, for each pixel of the color image corrected by the color image correction unit 106, the OCR image generation unit 108 calculates the luminance (hereinafter referred to as “Y”) from the RGB color components included in the pixel, for example, as in Equation 3 below. And the calculated luminance is set to the pixel value of the pixel in the grayscale image, thereby generating a grayscale image.

  Then, the OCR image generation unit 108 generates an OCR image by binarizing the generated grayscale image using a predetermined threshold, for example.

[2-2-6. OCR processing unit 110]
The OCR processing unit 110 performs character recognition on the OCR image generated by the OCR image generation unit 108.

[2-2-7. Communication unit 120]
The communication unit 120 transmits / receives information to / from other devices via the communication network 22. For example, the communication unit 120 receives a color image read by the scanner 20 from the scanner 20.

[2-2-8. Storage unit 122]
The storage unit 122 can store various data such as a brightness image generated by the brightness image generation unit 102 and a color image corrected by the color image correction unit 106.

  Note that the configuration of the information processing apparatus 10 according to the present embodiment is not limited to the configuration described above. For example, the information processing apparatus 10 may include a liquid crystal display (LCD) apparatus and the like, and may further include a display unit that displays a display screen. In addition, the information processing apparatus 10 may include a keyboard, a mouse, and the like, and further include an input unit that receives an input from the user. The information processing apparatus 10 may not include the OCR image generation unit 108 and the OCR processing unit 110.

<2-3. Operation>
The configuration according to this embodiment has been described above. Subsequently, an operation according to the present embodiment will be described.

  FIG. 9 is a flowchart showing the operation according to the present embodiment. As shown in FIG. 9, first, the communication unit 120 of the information processing apparatus 10 receives a color image read by the scanner 20 from the scanner 20 (S101).

  Subsequently, the brightness image generation unit 102 sets, for each pixel of the color image, the largest pixel value among the pixel values of the RGB color components of the pixel as the pixel value of the pixel at the same position in the brightness image. Then, a brightness image is generated (S102).

  Subsequently, the brightness image correction unit 104 performs a shadow correction process on the brightness image generated in S102 by, for example, a method substantially similar to the method described in JP-A-2002-15313 (S103).

  Subsequently, for each pixel of the color image received in S101, the color image correction unit 106 calculates the ratio of the pixel value of the pixel corrected in S103 to the pixel value of the same pixel in the brightness image generated in S102. By multiplying the pixel values of the RGB color components of the pixel in the color image, the pixel values of the RGB color components of the pixels of the color image are corrected (S104).

  Subsequently, the OCR image generation unit 108 generates a grayscale image based on the color image corrected in S104 (S105). Then, the OCR image generation unit 108 generates an OCR image by binarizing the generated grayscale image (S106).

  Thereafter, the OCR processing unit 110 performs character recognition on the OCR image generated in S106 (S107).

<2-4. Effect>
As described above, for example, as described with reference to FIGS. 2 and 9, the information processing apparatus 10 according to the present embodiment generates a grayscale brightness image based on a color image, and each of the generated brightness images. The pixel value of the pixel is corrected, and each color component of each pixel of the color image is corrected based on the correction result for the brightness image. Therefore, the result of correction performed on the brightness image indicating the brightness of each pixel of the color image is directly reflected in each color component of each pixel of the color image, so that the brightness distribution of each pixel of the color image is corrected. can do.

  For example, the information processing apparatus 10 sets the largest pixel value among the pixel values of the RGB color components of each pixel of the color image as the pixel value of each pixel in the brightness image. Then, for each pixel of the color image, the information processing apparatus 10 calculates the ratio of the pixel value of the pixel in the lightness image after correction to the pixel value of the same pixel in the lightness image before correction, for each color component of the pixel in the color image. Each color component of each pixel of the color image is corrected by multiplying the pixel value of.

  For this reason, the pixel value of each color component of RGB of each pixel of the color image after correction becomes equal to or lower than the upper limit value and does not become saturated. Therefore, no color shift occurs due to the correction, and the hue does not change from the color image before the correction.

  The information processing apparatus 10 can correct the dynamic shadow included in the color image with high accuracy by performing the above-described shadow correction processing on the brightness image. In general, when the scanner 20 is a non-contact type as shown in FIG. 1, the upper portion is not covered with a lid or the like, and when the user scans a paper medium, for example, a shadow of a hand or the like. Dynamic shadows are easy to enter. This is particularly effective when the color image is an image taken by the non-contact type scanner 20.

  As described above, according to the present embodiment, it is possible to correct the shadow included in the color image with high accuracy while maintaining the color tone in the color image before correction, so that the visibility of the color image can be improved. For the same reason, for example, the character recognition rate in the OCR processing can be improved as compared with the case where the OCR processing is performed based on the color image before correction.

<< 3. Hardware configuration >>
Next, the hardware configuration of the information processing apparatus 10 according to the present embodiment will be described with reference to FIG. As illustrated in FIG. 10, the information processing apparatus 10 includes a CPU 150, a ROM (Read Only Memory) 152, a RAM 154, an internal bus 156, an input / output interface 158, an HDD (Hard Disk Drive) 160, and a network interface 162.

<3-1. CPU 150>
The CPU 150 functions as an arithmetic processing device and a control device, and controls the overall operation in the information processing device 10 according to various programs. Further, the CPU 150 realizes the function of the control unit 100 in the information processing apparatus 10. The CPU 150 is configured by a processor such as a microprocessor.

<3-2. ROM152>
The ROM 152 stores programs used by the CPU 150, calculation parameters, and the like.

<3-3. RAM154>
The RAM 154 temporarily stores programs used in the execution of the CPU 150, parameters that change as appropriate during the execution, and the like.

<3-4. Internal bus 156>
The internal bus 156 is composed of a CPU bus and the like. The internal bus 156 connects the CPU 150, the ROM 152, and the RAM 154 to each other.

<3-5. Input / output interface 158>
The input / output interface 158 connects the HDD 160 and the network interface 162 to the internal bus 156. For example, the HDD 160 exchanges data with the RAM 154 or the like via the input / output interface 158 and the internal bus 156.

<3-6. HDD 160>
The HDD 160 is a data storage device that functions as the storage unit 122. The HDD 160 includes, for example, a storage medium, a recording device that records data on the storage medium, a reading device that reads data from the storage medium, and a deletion device that deletes data recorded on the storage medium. The HDD 160 stores programs executed by the CPU 150 and various data.

<3-7. Network Interface 162>
The network interface 162 is a communication interface configured by a communication device for connecting to a communication network such as the Internet, for example. This network interface 162 functions as the communication unit 120. The network interface 162 may be a wireless LAN compatible communication device, a LTE (Long Term Evolution) compatible communication device, or a wire communication device that performs wired communication.

<< 4. Modification >>
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

<4-1. Modification 1>
For example, in the above description, the color image correction unit 106 has been described mainly with respect to an example in which the pixel values of all the color components included in each pixel of the color image are corrected. However, the present invention is not limited to such an example. For example, the color image correction unit 106 can correct only one or only two of the RGB color components of each pixel of the color image.

<4-2. Modification 2>
In the above description, an example in which the color image in the present invention is an image taken by the scanner 20 has been described. However, the present invention is not limited to such an example. For example, the color image in the present invention may be an image obtained by photographing a subject such as a white board with a digital camera.

<4-3. Modification 3>
Further, when the scanner 20 has all the components included in the control unit 100 described above, the information processing apparatus according to the present invention may be the scanner 20. In this modification, the information processing apparatus 10 does not necessarily have to be provided.

<4-4. Modification 4>
In addition, according to the present embodiment, it is possible to provide a computer program for causing hardware such as the CPU 150, the ROM 152, and the RAM 154 to perform the same functions as the components of the information processing apparatus 10 described above. A recording medium on which the computer program is recorded is also provided.

DESCRIPTION OF SYMBOLS 10 Information processing apparatus 20 Scanner 22 Communication network 100 Control part 102 Lightness image generation part 104 Lightness image correction part 106 Color image correction part 108 OCR image generation part 110 OCR processing part 120 Communication part 122 Storage part 150 CPU
152 ROM
154 RAM
156 Internal bus 158 I / O interface 160 HDD
162 Network interface

Claims (10)

A brightness image generation unit that generates a brightness image based on a color image;
A brightness image correction unit that corrects pixel values of pixels included in the generated brightness image;
A color image correction unit that corrects a color component of a pixel included in the color image based on a result of correction by the brightness image correction unit;
An information processing apparatus comprising:   The information processing apparatus according to claim 1, wherein the brightness image is a grayscale image corresponding to a pixel value of a pixel included in the color image.   The pixel value of the first pixel included in the brightness image is a pixel value of a color component having the largest pixel value among a plurality of color components of the pixel corresponding to the first pixel in the color image. 2. The information processing apparatus according to 2.   The color image correction unit is configured to generate the color based on a ratio between a pixel value of a first pixel included in the generated brightness image and a pixel value of the first pixel corrected by the brightness image correction unit. The information processing apparatus according to claim 1, wherein a color component of a pixel corresponding to the first pixel is corrected in an image.   The color image correction unit corresponds to a ratio of a pixel value of the first pixel after correction to a pixel value of the first pixel included in the generated brightness image, corresponding to the first pixel in the color image. The information processing apparatus according to claim 4, wherein the color component of the pixel corresponding to the first pixel in the color image is corrected by multiplying the color component of the pixel to be corrected.   The brightness image correction unit corrects the pixel values of the first pixels included in the generated brightness image based on the pixel values of a plurality of pixels around the first pixels. The information processing apparatus according to claim 1.   The information processing apparatus according to claim 6, wherein the brightness image correction unit further corrects a pixel value of the first pixel based on distances between a plurality of pixels around the first pixel. .   The information processing apparatus according to claim 1, wherein color components of pixels included in the color image are RGB color components of pixels included in the color image. Generating a brightness image based on the color image;
Correcting the pixel values of the pixels included in the generated brightness image;
Correcting a color component of a pixel included in the color image based on the result of the correction;
An information processing method comprising: Computer
A brightness image generation unit that generates a brightness image based on a color image;
A brightness image correction unit that corrects pixel values of pixels included in the generated brightness image;
A color image correction unit that corrects a color component of a pixel included in the color image based on a result of the correction by the brightness image correction unit;
Program to function as

Images