JP4923914B2 - Image processing apparatus and image processing program - Google Patents

Description

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

  Conventionally, as a technique for specifying a location to be added to a predetermined document such as a form, Japanese Patent Application Laid-Open Publication No. 2003-28259 discloses that after pre-addition image and post-addition image alignment, before-addition image data and post-addition image There has been disclosed a technique for extracting a postscript portion by performing monochromatic / binarization of data and subtracting the pre-write image data from the post-write image data obtained thereby.

Further, in Patent Document 2, the images before and after the additional recording are divided into a predetermined number, the images are aligned for each divided region, and then the image before the additional recording is expanded, and the image data before the additional recording and the image data after the additional recording are added. A technique for extracting a postscript location by calculating an exclusive OR for each pixel of the above is disclosed.
JP 2004-80601 A JP 2004-341914 A

  The present invention has been made in the technical background as described above, and provides an image processing apparatus and an image processing program capable of specifying with high accuracy the location of additional writing performed on a halftone image. Objective.

In order to achieve the above object, an image processing apparatus according to a first aspect of the present invention provides first image information indicating an image of a document before additional writing and a first image indicating the image of the original after additional recording is performed. Acquisition means for acquiring two-image information as each pixel information composed of a plurality of bits, and for each pixel corresponding to the first image information and the second image information acquired by the acquisition means Deriving means for deriving third image information by performing subtraction or division of pixel information, and the third image information in the HLS color space indicated by hue H, luminance L, and saturation S. Obtained by a conversion means for converting into four image information, a reception means for receiving range information indicating a range of at least one of hue H, luminance L, and saturation S including the color of the additional recording, and the conversion means Said fourth image information Definitive, and a, a specifying means for specifying a location as location where the additional recording is performed to be within the scope indicated by the range information received by the receiving unit.

According to a second aspect of the present invention, in the first aspect of the present invention, the specifying unit is configured to determine a location where the additional recording is performed on a location where the luminance L is greater than a predetermined value in the fourth image information. Excluded from specific targets.

Furthermore, the invention described in claim 3 is a limitation in which the pixel information indicated by the third image information is limited to a value within a predetermined range in the invention described in claim 1 or claim 2. Means are further provided.

On the other hand, in order to achieve the above object, an image processing program according to claim 4 includes first image information indicating an image of a document before additional recording and an image of the document after additional recording are performed. An acquisition step of acquiring the second image information shown as each pixel information is composed of a plurality of bits, and pixels corresponding to the first image information and the second image information acquired by the acquisition step A derivation step of deriving third image information by subtracting or dividing pixel information for each pixel , and an HLS color space represented by hue H, luminance L, and saturation S. A conversion step for converting to the fourth image information; a reception step for receiving range information indicating a range of at least one of hue H, luminance L, and saturation S including the additional color; and the conversion step Run in the fourth image information obtained by-up, and a specifying step of specifying a location as location where the additional recording is performed to be within the scope indicated by the range information received by the reception step to the computer It is something to be made.

According to the first and fourth aspects of the invention, there is an effect that it is possible to specify the location of additional writing performed on the halftone image with high accuracy.
In addition, according to the invention of claim 1 and claim 4, it is possible to specify the location of additional writing with higher accuracy than when specifying the location of additional writing on a color space having no hue. The effect is obtained.
Furthermore, according to invention of Claim 1 and Claim 4, as a result of being able to narrow down the location where the additional writing was performed according to the color of additional writing, the location of additional writing can be specified more accurately. An effect is obtained.

According to the second aspect of the present invention, in the case of specifying the location where the additional writing is performed on the white document, it is possible to narrow down the location where the additional writing has been performed. The effect that a location can be specified is obtained.

Further, according to the third aspect of the present invention, the results can be enhanced versatility of the third image information, it is possible to improve convenience, effect is obtained that.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a configuration example of an image processing system 10 to which the present invention is applied. As shown in the figure, the image processing system 10 according to the present embodiment includes an image processing device 20 such as a personal computer and an image reading device 30 such as a scanner. The image processing device 20 and the image reading device 30 are electrically connected, and the image processing device 20 can acquire image data obtained by reading by the image reading device 30 from the image reading device 30.

  The image processing system 10 according to the present embodiment includes a document before additional writing by handwriting or stamping (hereinafter referred to as “original document before adding”) and a document after the additional writing (hereinafter referred to as “original document”). , “Added document”) is read by the image reading device 30, and based on the two image data obtained by this, the image processing device 20 identifies the location where the additional recording has been performed, and appends from the identified location. The extracted image portion is extracted. In the following, image data obtained by reading a document before appending is referred to as “image data before appending”, and image data obtained by reading a document after appending is referred to as “image data after appending”.

  The image reading device 30 according to the present embodiment acquires image data obtained by reading as each pixel value (pixel information) is composed of a plurality of bits (8 bits in the present embodiment). ing. In the image processing system 10 according to the present embodiment, the image reading apparatus 30 separates and reads an image of a document to be read into three primary colors R (red), G (green), and B (blue). A color scanner is applied.

  Next, with reference to FIG. 2, the main configuration of the electrical system of the image processing apparatus 20 having a particularly important role in the image processing system 10 will be described.

  As shown in the figure, the image processing apparatus 20 according to the present embodiment includes a CPU (central processing unit) 20A that controls the operation of the entire image processing apparatus 20, and a work area when the CPU 20A executes various processing programs. A RAM (Random Access Memory) 20B, a ROM (Read Only Memory) 20C in which various control programs, various parameters, and the like are stored in advance, a hard disk 20D that is a storage means used for storing various information, and various types A keyboard 20E used for inputting information, a display 20F used for displaying various types of information, and an input / output interface (I / F) 20G for exchanging various types of information with external devices are provided. These units are electrically connected to each other by a system bus BUS. Here, the image reading device 30 described above is connected to the input / output interface 20G.

  Accordingly, the CPU 20A accesses the RAM 20B, ROM 20C and hard disk 20D, acquires various input information via the keyboard 20E, displays various information on the display 20F, and various information with the image reading device 30 via the input / output interface 20G. Can be exchanged.

  FIG. 3 is a functional block diagram showing a functional configuration of the image processing apparatus 20 according to the present embodiment. As shown in the figure, the image processing apparatus 20 according to the present embodiment includes a calculation unit 22, a restriction unit 24, a write-once specifying unit 26 having a conversion unit 26A and a specifying unit 26B, and a storage unit 28. I have.

  The calculation unit 22 performs a subtraction operation on a pixel value for each corresponding pixel in the pre-addition image data and the post-addition image data acquired by the image reading device 30, or performs a division operation to obtain the result. The obtained image data (hereinafter referred to as “calculation result image data”) is output. In the image processing system 10 according to the present embodiment, color image data composed of R, G, and B is applied as image data to be processed. Therefore, the arithmetic unit 22 performs the subtraction operation or the division operation. Are performed separately for each of R, G, and B.

  Here, when the calculation unit 22 performs the subtraction calculation, assuming that the pixel value of the pre-recording image data is AV and the pixel value of the post-recording image data at the corresponding position is BV, the following equation (1) is used. The pixel value RV constituting the calculation result image data can be obtained.

RV = (255−BV) − (255−AV)
= AV-BV (1)
By the way, the subtraction result by the equation (1) is that the portion without additional writing is generally 0 (zero), and the additional writing portion has a value within the range of 1 to 255. An image is obtained using the calculation result image data obtained thereby. In the case of display or printing, an inverted image (negative image) is shown. Therefore, in this case, the subtraction result obtained by the expression (1) may be subtracted from the pixel value 255 corresponding to the white background. That is, by applying the following equation (2), it is possible to prevent an image when displayed or printed from being an inverted image.

RV = 255-{(255-BV)-(255-AV)}
= BV-AV + 255 (2)
FIG. 4A shows an example of the image before the additional recording indicated by the image data before the additional recording obtained by reading the portion where the halftone image is formed in the document before the additional recording by the image reading device 30. 4B, the post-recording image indicated by the post-recording image data obtained by reading the part of the halftone image after the additional recording is performed so as to overlap the halftone image. An example is shown.

  On the other hand, FIG. 5A shows pixel values in the A1-A2 cross section of the pre-append image shown in FIG. 4A, with R as an example, and the vertical axis is 255-Red (R pixels). Value). FIG. 5B shows the pixel value in the A1-A2 cross section of the post-recording image shown in FIG. 4B by taking R as an example, and the vertical axis is the same as in FIG. Is 255-Red (R pixel value). Further, FIG. 5C is calculated by inputting the pre-recording image data indicating the pre-recording image data shown in FIG. 4A and the post-recording image data indicating the post-recording image data shown in FIG. 7 shows pixel values of an A1-A2 cross section in an image indicated by calculation result image data output from the unit 22.

  As shown in FIG. 5C, since the pixel value hardly changes between the pre-addition image and the post-addition image except for the location where the additional recording is performed, the calculation result is almost 0 (zero). In the place where the process is performed, a change in the pixel value due to the additional writing appears as a calculation result. Therefore, the portion where the change appears can be specified as the portion where the additional writing has been performed.

  The above description is for the case where the pre-recording image data and post-recording image data are RGB image data. These image data are represented by C (cyan), M (magenta), and Y (yellow). If the color image data is composed or color image data composed of the four colors C, M, Y and K (black), the calculation result image data is composed of the following equation (3). The pixel value RV to be obtained can be obtained.

RV = BV-AV (3)
On the other hand, when the calculation unit 22 performs the above division calculation, assuming that the pixel value of the image data before additional recording is AV and the pixel value of the image data after additional recording at the corresponding position is BV, the calculation is performed according to the following equation (4). A pixel value RV constituting the result image data can be obtained.

RV = BV ÷ AV (4)
By the way, as for the division result by the equation (4), the portion where there is no additional writing is approximately 1.0, and the additional writing portion becomes a value in the range of 0 or more and less than 1.0 according to the density of the additional writing. It cannot be displayed or printed as an image. Therefore, when the display or printing is performed, the division result obtained by the expression (4) may be multiplied by 255. That is, by applying the following equation (5), a value that can be displayed or printed can be obtained.

RV = 255 × (BV ÷ AV) (5)
FIG. 6A shows pixel values in the A1-A2 cross section of the pre-recording image shown in FIG. FIG. 6B shows pixel values in the A1-A2 cross section of the post-recording image shown in FIG. Further, FIG. 6C is a diagram in which the pre-recording image data indicating the pre-recording image data shown in FIG. 4A and the post-recording image data indicating the post-recording image data shown in FIG. The pixel value of the A1-A2 cross section in the image shown by the calculation result image data output from the calculating part 22 which performs a calculation is shown.

  As shown in FIG. 6C, since the pixel value hardly changes between the pre-addition image and the post-addition image except for the location where the additional recording has been performed, the calculation result is approximately 1.0. In the place where it was performed, the calculation result is a value smaller than 1.0 by the amount of change in the pixel value due to additional writing. Therefore, the portion where the change appears can be specified as the portion where the additional writing has been performed.

  The above description is for the case where the image data before additional recording and the image data after additional recording are RGB image data. However, these image data are color image data composed of C, M, and Y, or C , M, Y, and K, the pixel value RV that constitutes the operation result image data can be obtained from the equation (4) or (5).

  By the way, the value obtained by the calculation by the calculation unit 22 may be out of the normal range of the pixel value, and it is necessary to make such a pixel usable in later processing without causing an error.

  For example, when the calculation unit 22 performs the subtraction calculation according to the expression (1), when “the pixel value of the post-recording image> the pixel value of the pre-addition image”, the calculation result is a negative value, and the calculation unit 22 (2 When the subtraction calculation is performed using the formula (1), the calculation result is larger than 255 when “pixel value of post-recording image> pixel value of pre-recording image”.

  Therefore, the limiting unit 24 limits each pixel value in the calculation result image data to a value within a predetermined range. In the image processing system 10 according to the present embodiment, an 8-bit configuration is used as the image data, and therefore a range from 0 to 255 is applied as the predetermined range. That is, the limiting unit 24 sets the pixel value that is less than 0 among the pixel values of the calculation result image data input from the calculation unit 22 to 0, and sets the pixel value that is greater than 255 to 255. It is supposed to be.

  By the way, the inventors of the present invention, color image data composed of R, G, B, color image data composed of C, M, Y, or color composed of C, M, Y, K. After the calculation result image data output from the calculation unit 22 using the image data as input data is converted into image data in the HLS color space, the portion overlapping the halftone image of the additional recording portion of the same color and the halftone image are overlapped. As a result of comparison with the non-existing portion, it was found that although there was a large difference in luminance L and saturation S, the difference in hue H was extremely small.

  That is, the inventors of the present invention firstly, as schematically shown in FIG. 7A as an example, a background area a and a write-on area when a red writing tool is used to write a portion where the background is green. When hue H was measured at a plurality of locations in three areas of b and the overlapping area c where the additional writing overlapped with the background, and the distribution thereof was examined, it was as shown in FIG. 7B as an example. Further, as schematically shown in FIG. 8A as an example, the background region d, the additional recording region e, and the additional recording overlap when the additional writing is performed with the red writing tool on the portion where the background is blue. When the hue H was measured for a plurality of locations in the three regions of the overlapping region f and the distribution thereof was examined, it was as shown in FIG. 8B as an example.

  Next, the inventors of the present invention input the pre-recording image data and post-recording image data in the image shown in FIG. 7A as an example, and the calculation result image data output from the calculation unit 22 is converted to HLS color. After conversion to spatial image data, the hue H was measured at a plurality of locations in the three areas of the background area a, the additional recording area b, and the overlapping area c, and the distribution thereof was examined. As an example, FIG. It became a thing. FIG. 9A schematically shows an image indicated by the calculation result image data in this case. Further, as an example, after inputting pre-recording image data and post-recording image data in the image shown in FIG. 8A and converting the calculation result image data output from the calculation unit 22 into image data in the HLS color space, The hue H was measured at a plurality of locations in the three areas of the background area d, the additional recording area e, and the overlapping area f, and the distribution thereof was examined. The distribution was as shown in FIG. 10B as an example. FIG. 10A schematically shows an image indicated by the calculation result image data in this case.

  Comparing FIG. 7B and FIG. 9B, the distribution area of the hue H in the overlapping area c moves in the direction of the distribution area of the hue H in the additional recording area b, so that the distribution area of the additional recording area b is significantly different. You can see that they are approaching. Further, when FIG. 8B is compared with FIG. 10B, the distribution area of the hue H of the overlapping area f moves in the direction of the distribution area of the hue H of the additional recording area f, and the distribution area of the additional recording area f is compared. It turns out that it is approaching remarkably.

  On the other hand, with respect to the luminance L and the saturation S, the approach of the distribution region such as the hue H was not observed. This tendency was also observed for color image data composed of C, M, Y and color image data composed of C, M, Y, K.

  Therefore, the conversion unit 26A converts the calculation result image data output from the restriction unit 24 into converted image data that is image data of a predetermined color space (HLS color space in the present embodiment) having a hue H. Convert to

  Then, the specifying unit 26B specifies the location where the additional recording has been performed based on the converted image data obtained by the conversion unit 26A, and stores the information indicating the location where the additional recording has been performed in the storage unit 28. In the image processing system 10 according to the present embodiment, range information indicating a range of at least one of the hue H, the luminance L, and the saturation S including the color of additional writing is received, and the specifying unit 26 In the converted image data, the position of the pixel included in the range indicated by the range information is specified as the location where the additional writing has been performed.

  In addition, the process by each component (the calculating part 22, the restriction | limiting part 24, the conversion part 26A, the specific | specification part 26B) of the image processing apparatus 20 comprised as mentioned above uses a computer by running a program. It can be realized by a software configuration. In this case, the program includes the image processing program of the present invention. However, the present invention is not limited to realization by a software configuration, and needless to say, it can also be realized by a hardware configuration or a combination of a hardware configuration and a software configuration.

  Hereinafter, a description will be given of a case where the image processing system 10 according to the present embodiment is configured to realize processing by each of the above-described components by executing the above-described program (hereinafter referred to as “image processing program”). To do. In this case, the image processing program is installed in the image processing apparatus 20 in advance, provided in a state stored in a computer-readable recording medium, or distributed via wired or wireless communication means. Forms and the like can be applied.

  Next, the operation of the image processing system 10 according to the present embodiment will be described with reference to FIG. FIG. 11 is a flowchart showing the flow of processing of the image processing program executed by the CPU 20A of the image processing apparatus 20. Also, here, in order to avoid complications, the color of the additional writing to be specified is set to four colors of black, red, green, and blue, and the range information corresponding to these colors is input via the keyboard 20E. A case where the data is stored in advance in a predetermined area of the hard disk 20D will be described. In this case, the keyboard 20E corresponds to the receiving means of the present invention. Furthermore, here, in order to avoid complications, the pre-recording image data and post-recording image data to be processed are input from the image reading apparatus 30 as indicating the same size original document image, and are previously stored in a predetermined area of the hard disk 20D. The case where it is stored will be described.

  In step 100 of the figure, the pre-addition image data and post-addition image data to be processed are acquired by reading from the hard disk 20D, and in the next step 102, the width of the image indicated by each read image data (here, The number of pixels in the horizontal direction of the image is substituted into the variable W, and the height of the image (here, the number of pixels in the vertical direction of the image) is substituted into the variable T.

  In the next step 104, 0 is substituted for the variable i. In the next step 106, 0 is substituted for the variable k. In the next step 108, the height direction position in the pre-addition image data and the post-addition image data is displayed. Is subtracted for each R, G, B pixel value using the pixel value at the position indicated by the value of variable i and the position in the width direction indicated by the value of variable k. . As described above, in the image processing program according to the present embodiment, the subtraction operation according to the equation (1) is performed in this step 108. However, the present invention is not limited to this. For example, the subtraction operation according to the equation (2) Needless to say, it is possible to perform a division operation according to the equations (4) and (5). Note that the pre-additional image indicated by the pre-additional image data and the post-additional image indicated by the post-additional image data are caused by a difference in inclination angle between the pre-addition original and the post-addition original when the image reader 30 reads the image. Since the corresponding pixels may be misaligned, it is preferable to align each image data using a conventionally known technique prior to the execution of the subtraction operation. The process of step 108 corresponds to the process of the calculation unit 22.

  In the next step 110, the values obtained by the calculation in the above step 108 (pixel values for each of R, G, and B, hereinafter referred to as “calculated values”) are within a predetermined range (in the present embodiment, In the range of 0 or more and 255 or less), and if a negative determination is made, the process proceeds to step 112 to clamp the calculated value within the predetermined range (in the present embodiment, the above If the calculated value is less than 0, the value is 0. If the calculated value is greater than 255, the value is set to 255.) After that, the process proceeds to step 114. Then, the process proceeds to step 114 without executing the process of step 112 described above. The processing from step 110 to step 112 corresponds to the processing of the restriction unit 24.

  In step 114, the calculated value is converted into a value in the HLS color space (hereinafter referred to as "conversion value"). The process of step 114 corresponds to the process of the conversion unit 26A.

  In the next step 116, is the luminance L in the converted value larger than a first threshold value (for example, 240) stored in a predetermined area of the hard disk 20D in advance as a lower limit value of the luminance L of the background color of the postscript document? If the determination is negative and the determination is affirmative, the routine proceeds to step 134 described later, whereas if the determination is negative, the routine proceeds to step 118.

  In step 118, information indicating the range including the black additional writing in the range information (in this embodiment, the luminance L is less than the second threshold (10 as an example), or the saturation S is the third threshold (as an example). 15) is read from the hard disk 20D, and it is determined whether or not the converted value is included in the range indicated by the information. If the determination is affirmative, the process proceeds to step 120. After storing the information indicating that the position of the pixel corresponding to the conversion value is the additional writing location in black, the process proceeds to step 134. On the other hand, if the determination in step 118 is negative, the process proceeds to step 122.

  In step 122, information indicating the range including the red addition in the range information (in this embodiment, the hue H is equal to or higher than the fourth threshold value (as an example, 236 degrees), or the fifth threshold value (as an example, 20 degrees). ) The following information is read from the hard disk 20D, and it is determined whether or not the converted value is included in the range indicated by the information. After storing the information indicating that the position of the pixel corresponding to is a postscript location in red, the process proceeds to step 134. On the other hand, if the determination in step 122 is negative, the process proceeds to step 126.

  In step 126, information indicating a range in which the additional information of green is included in the range information (in this embodiment, the hue H is equal to or greater than the sixth threshold value (as an example, 65 degrees) and the seventh threshold value (as an example, 105 Degree) The following information is read from the hard disk 20D, and it is determined whether or not the conversion value is included in the range indicated by the information. After storing the information indicating that the position of the pixel corresponding to the value is the additional writing location in green, the process proceeds to step 134. On the other hand, if the determination in step 126 is negative, the process proceeds to step 130.

  In step 130, information indicating the range including the blue additional writing in the range information (in this embodiment, the hue H is equal to or higher than the eighth threshold value (as an example, 150 degrees) and the ninth threshold value (as an example, 190). Degree) The following information is read from the hard disk 20D, and it is determined whether or not the conversion value is included in the range indicated by the information. After storing the information indicating that the position of the pixel corresponding to the value is a place to be additionally written in blue, the process proceeds to step 134. On the other hand, if the determination in step 130 is negative, the process in step 132 is executed. Then, the process proceeds to step 134.

  In step 134, the value of the variable k is incremented by 1. In the next step 136, it is determined whether or not the value of the variable k is less than the value of the variable W (value indicating the width of the image). If the determination is affirmative, the process returns to step 108, and the processing after step 108 is executed again. On the other hand, if the determination is negative, the process proceeds to step 138.

  In step 138, the value of the variable i is incremented by 1. In the next step 140, it is determined whether or not the value of the variable i is less than the value of the variable T (value indicating the height of the image). If the determination is affirmative, the process returns to step 106, and the processing subsequent to step 106 is executed again. If the determination is negative, the image processing program is terminated. The processing from step 116 to step 132 corresponds to the processing of the specifying unit 26B.

  It should be noted that information indicating that the position of the pixel corresponding to the converted value is an additional write location in each of the steps 120, 124, 128, and 132 is stored in the image processing according to the present embodiment. In the program, image data indicating a white image having a width indicated by a variable W and a height indicated by a variable T is prepared in advance for each type of additional recording color, and for each additional recording color, the corresponding image data is provided. However, the conversion is performed by replacing the corresponding pixel value with the conversion value of the corresponding color. However, the present invention is not limited to this, and for each additional recording color, a position indicating the conversion value and the position of the conversion value on the image. Other forms such as a form for storing information in association with each other, and a case in which a conversion value is not required in subsequent processing, such as a form for storing only the position information for each additional color Can it is needless to say.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various modifications or improvements can be added to the above-described embodiment without departing from the gist of the invention, and embodiments to which such modifications or improvements are added are also included in the technical scope of the present invention.

  The above embodiments do not limit the invention according to the claims (claims), and all the combinations of features described in the embodiments are essential for the solution of the invention. Is not limited. The above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. Even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, as long as an effect is obtained, a configuration from which these some constituent requirements are deleted can be extracted as an invention.

  For example, in the above embodiment, the case where the image processing is realized by the software configuration has been described. However, the present invention is not limited to this, and for example, the image processing is realized by the hardware configuration. You can also. As an example of the form in this case, for example, a functional device that executes the same processing as each component (calculating unit 22, limiting unit 24, converting unit 26A, specifying unit 26B) of the image processing apparatus 20 shown in FIG. Examples of forms that are created and used are illustrated. In this case, the image processing can be speeded up as compared with the above embodiment.

  In the above embodiment, the case where the HLS color space is applied as the color space having the hue of the present invention has been described. However, the present invention is not limited to this, and for example, the hue such as the HSV color space is used. It can also be set as the form which applies the other color space which has. In this case as well, the same effects as in the above embodiment can be obtained.

  In addition, the configurations (see FIGS. 1 to 3) of the image processing system 10 and the image processing apparatus 20 described in the above embodiment are merely examples, and unnecessary portions are deleted without departing from the gist of the present invention. Needless to say, you can add new parts.

  Further, various arithmetic expressions described in the above embodiment (see Expressions (1) to (5)) are also examples, and it goes without saying that changes can be made without departing from the gist of the present invention.

  Furthermore, the processing flow of the image processing program described in the above embodiment (see FIG. 11) is also an example, and unnecessary steps are deleted or new steps are added without departing from the gist of the present invention. Needless to say, the processing order can be changed.

1 is a block diagram illustrating a configuration of an image processing system according to an embodiment. It is a block diagram which shows the principal part structure of the electric system of the image processing apparatus which concerns on embodiment. It is a functional block diagram which shows the functional structure of the image processing apparatus which concerns on embodiment. It is a figure with which it uses for description of the calculation by the calculating part which concerns on embodiment, and is a top view which shows an example of the image before additional recording and the image after additional recording. It is a figure with which it uses for description of the said calculation in case the calculating part which concerns on embodiment performs a subtraction calculation. It is a figure with which it uses for description of the said calculation in case the calculating part which concerns on embodiment performs a division operation. It is a schematic diagram with which it uses for description of the conversion part and specific part which concern on embodiment. It is another schematic diagram with which it uses for description of the conversion part which concerns on embodiment, and a specific part. It is another schematic diagram with which it uses for description of the conversion part which concerns on embodiment, and a specific part. It is another schematic diagram with which it uses for description of the conversion part which concerns on embodiment, and a specific part. It is a flowchart which shows the flow of a process of the image processing program which concerns on embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image processing system 20 Image processing apparatus 20A CPU
20D hard disk 20E keyboard (accepting means)
22 Calculation unit (derivation means)
24 Restriction part (restriction means)
26 appending specification part 26A conversion part (conversion means)
26B identification part (identification means)
28 storage unit 30 image reading device (acquisition means)

Claims (4)

The first image information indicating the image of the document before the additional recording is performed and the second image information indicating the image of the document after the additional recording are performed, each pixel information is composed of a plurality of bits. Acquisition means for acquiring;
Deriving means for deriving third image information by subtracting or dividing pixel information for each corresponding pixel of the first image information and the second image information obtained by the obtaining means;
Conversion means for converting the third image information into fourth image information in an HLS color space indicated by hue H, luminance L, and saturation S;
Receiving means for receiving range information indicating a range of at least one of hue H, luminance L, and saturation S including the color of the additional writing;
In the fourth image information obtained by the converting means, a specifying means for specifying a place included in the range indicated by the range information received by the receiving means as a place where the additional writing is performed,
An image processing apparatus. The specifying unit excludes a portion where the luminance L is larger than a predetermined value in the fourth image information from a specifying target of the portion where the additional recording is performed.
The image processing apparatus according to claim 1 . The image processing apparatus of the pixel information, further claim 1 or claim 2, wherein comprising a limiting means for limiting to a value within a predetermined range indicated by the third image information. The first image information indicating the image of the document before the additional recording is performed and the second image information indicating the image of the document after the additional recording are performed, each pixel information is composed of a plurality of bits. An acquisition step to acquire;
Deriving step of deriving third image information by subtracting or dividing pixel information for each corresponding pixel of the first image information and second image information acquired by the acquiring step;
A conversion step of converting the third image information into fourth image information of an HLS color space indicated by hue H, luminance L, and saturation S;
A receiving step for receiving range information indicating a range of at least one of hue H, luminance L, and saturation S including the color of the additional writing;
In the fourth image information obtained by the conversion step, a specifying step for specifying a location included in the range indicated by the range information received by the receiving step as a location where the additional writing has been performed,
An image processing program for causing a computer to execute.

Images