JP4479731B2 - Image reading apparatus and image reading processing program - Google Patents

Description

  The present invention relates to an image reading apparatus and an image reading processing program, and more particularly, to an image reading apparatus and an image reading processing program that can output at an appropriate density according to the type of document.

  When an image drawn on a document is read and printed, a darkly drawn portion can be identified, but a thinly drawn portion may be difficult or impossible to identify. In addition, when a color image is printed as a monochrome image, or when a color image is received by facsimile and printed as a monochrome image, an image that can be identified with a color image may become unidentifiable with a monochrome image or become unclear. Sometimes. In particular, when a paper image copied using carbon paper is scanned and the image is printed as a monochrome image, the density of characters and the like transferred by the carbon paper is thin, and is not printed clearly.

In Japanese Patent Application Laid-Open No. 8-44818 (Patent Document 1), when carbon paper can be used to write characters on a plurality of papers at a time, the paper overlapped below becomes thinner. A technique is disclosed in which an identification mark for identifying the number of sheets from above is added to a sheet in advance, and the density of the image is changed by determining the identification mark.
JP-A-8-44818

  However, in the technique described in Patent Document 1, when copying a manuscript copied using carbon paper (hereinafter referred to as carbon copy), the number of sheets from the top is identified in advance. When the identification mark is added, the density can be adjusted. However, when the identification mark is not added to the paper, the density cannot be adjusted.

  SUMMARY An advantage of some aspects of the invention is that it provides an image reading apparatus and an image reading processing program capable of outputting an appropriate density according to the type of document.

In order to achieve this object, an image reading apparatus according to claim 1 includes an image reading unit that reads at least a monochrome image, and a moving unit that relatively moves the image reading unit and the document. A determination for determining the type of the original, which is provided on one end side of the original in the moving direction by the moving means, and repeats the reading operation by the image reading means and the moving operation by the moving means. A determination range processing unit that reads a range as a monochrome image using the image reading unit, and detects a lightness value of a monochrome image in the determination range read by the determination range processing unit, and a lightness value of a pixel in the determination range and brightness detecting means for calculating the average brightness value by averaging the average brightness value calculated by the brightness detecting means is within a predetermined range A determination unit that determines that the document is a special document; and when the determination unit determines that the document is a special document, each pixel constituting the monochrome image read by the image reading unit Output means for changing the density value so as to increase the density.

The image reading apparatus according to claim 2, further comprising: an image reading unit that reads a document as a color image or a monochrome image; and a moving unit that relatively moves the image reading unit and the document. And the moving operation by the moving means are repeated to read the original, provided on one end side of the original in the moving direction by the moving means, and a determination range for determining the type of the original is the image reading means A determination range processing unit that reads a color image using the image, and detects a brightness value and a saturation value of the color image in the determination range read by the determination range processing unit, and the brightness value of the pixels in the determination range and and color information detecting means for calculating a mean brightness value and the average saturation value by averaging the saturation value, respectively, calculated by the color information detecting unit The average brightness value is within a predetermined range, and when the average saturation value included in a predetermined range, and determination means for the document is determined to be a special document, the document is a special document by the determining means If it is determined that there is, output means for changing the density value of each pixel constituting the monochrome image read by the image reading means so as to increase the density is provided.

According to a third aspect of the present invention, there is provided the image reading apparatus according to the first or second aspect , further comprising an edge detecting unit that detects one end of the document, and the determination range processing unit is detected by the edge detecting unit. Further, the image is read with a band-like range inside the width of about 3 mm from one end of the document to the other end side and along the one end detected by the edge detecting means as the determination range.

The image reading apparatus according to claim 4 is the image reading apparatus according to any one of claims 1 to 3 , wherein the output unit determines that the original is a special original when the determination unit determines that the original is a special original. Of the monochrome image read by the image reading means, the density value of each pixel constituting the image excluding the determination range is changed and output so that the density is high.

6. The image reading apparatus according to claim 5 , further comprising an image reading unit that reads at least a monochrome image of a document, a prescan processing unit that reads the entire range of the document as a monochrome image by the image reading unit, and a press thereof. Edge detection means for detecting a plurality of edges of the document based on the monochrome image read by the can processing means, and a band-like range inside the document along the plurality of edges detected by the edge detection means as a determination range, and brightness detecting means for calculating the average brightness value by its brightness value of the determination range is detected based on the monochromatic image read by the prescan processing means averages the brightness values of the pixels in the determination range, the If the average brightness value calculated by the brightness detecting means is within a predetermined range, it determines that the original is the special original And a main scanning processing unit that reads the original again as a monochrome image by the image reading unit, and the determination unit determines that the original is a special original. In such a case, there is provided output means for changing the density value of each pixel constituting the monochrome image read by the main scan processing means so as to increase the density.

The image reading apparatus according to claim 6 includes an image reading unit that reads a document as a color image or a monochrome image, and a prescan processing unit that reads the entire range of the document as a color image by the image reading unit; Edge detection means for detecting a plurality of edges of the document based on the color image read by the pre-scan processing means, and a determination range for the belt-like area inside the document along the plurality of edges detected by the edge detection means by the by, detected on the basis of the color image read by the prescan processing means the lightness and saturation values of the determination range, the average brightness value and the saturation value of the pixels in the determination range, respectively Tokoro and color information detecting means for calculating a mean brightness value and the average saturation value, the average brightness value calculated by the color information detecting means Within the scope of, and when the average saturation value included in a predetermined range, and determination means for the document is determined to be a special document, after reading a color image by the prescan processing unit, the image A main scanning processing unit that reads the original again as a monochrome image by the reading unit, and each of the monochrome images that are read by the main scanning processing unit when the determination unit determines that the original is a special original. Output means for changing and outputting the density value of the pixel so that the density becomes high.

Billing an image reading apparatus in claim 7, wherein, in the image reading apparatus according to claim 5, wherein said lightness detection means, from the detected edge by the edge detecting means, a substantially 3mm toward the edge side opposite to that edge The lightness value of the determination range is detected using a band-shaped range inside the width and along the edge detected by the edge detection means as a determination range.

An image reading apparatus according to an eighth aspect of the present invention is the image reading apparatus according to the sixth aspect , wherein the color information detecting means is approximately 3 mm from the edge detected by the edge detecting means toward an edge facing the edge. The lightness value and the saturation value of the determination range are detected using the band-like range along the edge detected by the edge detection means as the determination range.

An image reading apparatus according to claim 9 is an image storing the image of the entire range of the document read at a predetermined resolution by the prescan processing means in the image reading apparatus according to any one of claims 5 to 8. An information storage means, wherein the edge detection means detects a plurality of edges of the document based on the image stored by the image information storage means, and the main scan processing means is based on the reading resolution of the prescan processing means. A monochrome image is acquired by the image reading means at a high resolution.

11. The image reading device according to claim 10, wherein the image reading device according to claim 1 or 5 detects a white pixel having a lightness value of a pixel constituting an image read by the image reading means greater than a predetermined lightness value. White pixel detection means for removing the white pixels detected by the white pixel detection means from the pixels constituting the image of the determination range, and then calculating the brightness values of the pixels in the determination range. you calculate the average brightness values averaged is also of a.

The image reading apparatus according to claim 11, wherein, in the image reading apparatus according to claim 1 or 5, comprising a ground color detecting means for detecting a background color based on the image read by the image reading means, said lightness detection means, after excluding the pixels of the detected background color by the background color detecting means from the pixels constituting the image of the determination range, that to calculate the average brightness value obtained by averaging the brightness values of the pixels in the determination range It is also of the.

The image reading device according to claim 12 is the image reading device according to any one of claims 2, 6 , and 8 , wherein a lightness value of a pixel constituting the color image read by the image reading unit is a predetermined lightness value. White pixel detection means for detecting a larger white pixel, wherein the color information detection means excludes the white pixel detected by the white pixel detection means from pixels constituting the image of the determination range, and then performs the determination it calculates the range of the mean brightness value and the average saturation value of the brightness value and the saturation value by averaging each pixel also of the a.

The image reading device according to claim 13 is the image reading device according to any one of claims 2, 6 and 8 , based on a saturation value of a pixel constituting a color image read by the image reading means. Achromatic color pixel detecting means for detecting achromatic color pixels, wherein the color information detecting means excludes the achromatic color pixels detected by the achromatic color pixel detecting means from the pixels constituting the image of the determination range; , you calculate the average brightness value and the average saturation lightness values and chroma values were averaged each pixel of the determination range is also the in is.

The image reading device according to claim 14 is the image reading device according to any one of claims 2, 6 , and 8 , wherein a ground color detecting unit detects a ground color based on a color image read by the image reading unit. The color information detecting means removes the ground color pixels detected by the ground color detecting means from the pixels constituting the image of the judgment range, and then the brightness value and saturation of the pixels of the judgment range you calculate the average brightness value a value obtained by averaging each and average saturation is also of a.

The image reading device according to claim 15 is the image reading device according to any one of claims 12 to 14 , wherein the color information detecting means has a hue value of a pixel constituting the image in the determination range within a predetermined range. A certain pixel is extracted, and the lightness value or saturation value of the extracted pixel is averaged to calculate the average lightness value or average saturation value.

17. The image reading processing program according to claim 16 , comprising image reading means capable of reading a document at least as a monochrome image, and moving means for relatively moving the image reading means and the document. Is performed in the image reading apparatus that reads the original by repeatedly performing the reading operation by the moving means and the moving operation by the moving means, and is provided on one end side of the original in the moving direction by the moving means, and determines the type of the original A determination range processing step of reading a determination range for performing a monochrome image using the image reading unit, and detecting a brightness value of the monochrome image of the determination range read by the determination range processing step , and brightness detecting step of calculating the average brightness value by averaging the brightness values of the pixels, the lightness detection step Ri when the average brightness value calculated is within a predetermined range, a judgment step in which the document is judged to be the special original, if the original by said determining step is determined to be a special document, the An output step of changing the density value of each pixel constituting the monochrome image read by the image reading means so as to increase the density.

The image reading processing program according to claim 17 comprises an image reading means for reading a document as a color image or a monochrome image, and a moving means for relatively moving the image reading means and the document, and reading by the image reading means. An image reading apparatus that reads the document by repeatedly performing an operation and a moving operation by the moving unit, and is provided on one end side of the document in the moving direction by the moving unit to determine the type of the document. A determination range processing step of reading the determination range as a color image using the image reading means, and a lightness value and a saturation value of the color image in the determination range read by the determination range processing step , and the determination color for calculating an average brightness value and an average saturation value by averaging the brightness values and saturation values of the pixels within each A broadcast detecting step, the average brightness value calculated by the color information detecting step is within a predetermined range, and when the average saturation value included in a predetermined range, the document is determined to be a special document When the determination step and the determination step determine that the original is a special original, the density value of each pixel constituting the monochrome image read by the image reading unit is changed so as to increase the density. And an output step for outputting.

An image reading processing program according to claim 18 is executed in an image reading apparatus including an image reading unit capable of reading at least a monochrome image of an original, and the entire range of the original is read by the image reading unit. A prescan processing step for reading with a monochrome image, an edge detection step for detecting a plurality of edges of the document based on the monochrome image read by the prescan processing step, and a plurality of edges detected by the edge detection step the inside of the strip in the range of the original and the determination range, by the detected based on the monochromatic image read by the lightness value of the determination range the prescan processing means averages the brightness values of the pixels in the determination range and brightness detecting step of calculating the mean brightness value, calculated by the brightness detection step If the average brightness value is within a predetermined range, a judgment step in which the document is determined to be a special document, after reading the manuscript by the prescan processing step, the original by the image reading unit again When the original scan processing step for reading with a monochrome image and the determination step determine that the original is a special original, the density value of each pixel constituting the monochrome image read by the main scan processing means is And an output step for changing the output to be darker.

The image reading processing program according to claim 19 is executed in an image reading apparatus including an image reading unit that reads a document as a color image or a monochrome image, and the entire range of the document is read by the image reading unit as a color image. A pre-scan processing step that is read in step 1, an edge detection step that detects a plurality of edges of the document based on the color image that is read in the pre-scan processing step, An inner band-shaped range is set as a determination range, and the brightness value and the saturation value of the determination range are detected based on the color image read by the prescan processing unit, and the brightness value and the saturation of the pixels in the determination range are detected. color information detection for calculating an average brightness value and an average saturation value by averaging degrees value, respectively Determining step of the step, the average brightness value calculated by the color information detecting step is within a predetermined range, and when the average saturation value included in a predetermined range, the document is determined to be a special document And after the color image is read by the pre-scan processing step, the original scanning process step of reading the original document again as a monochrome image by the image reading unit, and the determination step determines that the original document is a special original document. Includes an output step of changing the density value of each pixel constituting the monochrome image read by the main scan processing step so as to increase the density.

  For example, a special manuscript (hereinafter referred to as “special manuscript”) that is copied via carbon paper often has carbon paper ink attached near the edges of the manuscript. Since the density of the ink is higher than the density of the background color of the document, if the ink is attached to the document, the brightness of the portion to which the ink is attached becomes low. Therefore, an image near the edge of the document is read, the brightness of the read image is detected, and whether the document is a special document can be determined based on whether the brightness is within a predetermined range.

According to the image processing apparatus of the first aspect, the determination range for determining the type of document is provided on one end side in a direction perpendicular to the moving direction of the image reading means, and an image in the determination range is displayed. Ru is read by determining the range processing means. When the determination unit determines that the document is a special document, the output unit changes the density value of each pixel constituting the read monochrome image so as to increase the density.

  The image formed on the special document is often a thin image. However, according to claim 1, since this thin image is output by the output means so that the density is increased, it is output according to the type of the document. There is an effect that it is possible to output at an appropriate density. Since the image is output at an appropriate density according to the type of document, the user does not need to manually set the apparatus to correct the density according to the type of document, which is convenient. Further, since it is determined that the document is a special document based on the image in the determination range provided on one end side of the document, the determination process is performed as compared with the case where the document is determined to be a special document based on the image of the entire document. There is also an effect that it can be performed at high speed.

According to the image reading apparatus of the present invention, the determination range for determining the type of document is provided on one end side in a direction perpendicular to the moving direction of the reading unit, and the color image in the determination range is displayed. It is read by the determination range processing means . Near the end of the special original, the ink such as carbon paper is deposited, the ink has a color such as blue or red, lightness value and a chroma value representing the color is detected. Since only the brightness (luminance) is obtained from the monochrome image, but not be this transgression identifying a chromatic color of the image and the achromatic image, such as chroma values and the hue is obtained from the color image, by its saturation value, and achromatic image and chromatic color image can identification be Rukoto. Since the determination unit performs the determination based on the average brightness value and the average saturation value, it can determine whether the document is a special document with higher accuracy than when determining whether the document is a special document based on the brightness. There is an effect.

  When the determination unit determines that the document is a special document, the output unit changes the density value of each pixel constituting the read monochrome image so as to increase the density. The image formed on the special document is often a thin image. However, according to claim 2, the thin image is output so that the density is increased by the output means. There is an effect that it is possible to output at an appropriate density. Since the image is output at an appropriate density according to the type of document, the user does not need to manually set the apparatus to correct the density according to the type of document, which is convenient. Further, since it is determined that the document is a special document based on the image in the determination range provided on one end side of the document, the determination process is performed as compared with the case where the document is determined to be a special document based on the image of the entire document. There is also an effect that it can be performed at high speed.

According to the image reading apparatus of the third aspect , in addition to the effect produced by the image reading apparatus of the first or second aspect , the edge detection unit detects one end of the document, and the determination range processing unit detects the detection. The image is read with a band-shaped range inside the width of about 3 mm from one end of the original to the other end side along the detected one end as a determination range. Then, based on the read image, it is determined whether the document is a special document. Ink of carbon paper or the like adheres to the inside of the special document along a width of about 3 mm, and it can be determined whether the document is a special document by reading only an image in this range. Since this approximately 3 mm width is a very narrow range compared to the entire document, the determination process can be performed at a higher speed than when determining whether the document is a special document based on the image of the entire document. effective.

According to the image reading apparatus of the fourth aspect , in addition to the effect produced by the image reading apparatus according to any one of the first to third aspects, when the determination means determines that the original is a special original, the output means Then, the density value of each pixel constituting the image excluding the determination range in the read monochrome image is changed so as to increase the density and output. When the determination unit determines that the document is a special document, for example, ink is attached to the determination range, and an image with the ink attached is read. When the density of the image to which the ink is attached is increased, for example, printing is performed, the portion to which the ink is attached is printed darkly and is difficult to see, but this portion is not changed so as to increase the density. Therefore, there is an effect that a beautiful image can be formed.

According to the image reading apparatus of the fifth aspect, the monochrome image of the entire range of the document is read by the pre-scan processing unit, and a plurality of edges of the document are detected by the edge detection unit based on the monochrome image. The lightness detection means detects the lightness value of the determination range using the band-like range inside the document along the detected plurality of edges as the determination range. A special document is generally rectangular and has four sides, and ink such as carbon paper is often attached in the vicinity of one of the four sides. In the case where it is detected whether or not ink is attached to only one side of the document, it may not be detected. However, in claim 5 , since detection is made for a plurality of sides, it can be detected with higher accuracy. There is an effect. The determination unit determines that the document is a special document when the average brightness value calculated by the brightness detection unit is included in a predetermined range. Since the density of the ink is higher than the density of the background color of the original, if the ink is attached to the original, the brightness of the image of the portion where the ink is attached is lowered. Therefore, it is possible to determine whether or not the ink is attached by detecting the brightness value of the read image, and the determination unit determines that the original is a special document when the ink is attached.

The main scan processing unit reads the original document again as a monochrome image, and when the determination unit determines that the original document is a special document, the output unit determines the density of each pixel constituting the monochrome image read by the main scan processing unit. Change the value to increase the density and output. The image formed on the special document is often a thin image. However, according to claim 5 , the thin image is output so that the density is increased by the output means, so that it is output according to the type of the document. There is an effect that it is possible to output at an appropriate density. Since the image is output at an appropriate density according to the type of document, the user does not need to manually set the apparatus to correct the density according to the type of document, which is convenient.

According to the image reading apparatus of the sixth aspect, the color image of the entire range of the document is read by the pre-scan processing unit, and a plurality of edges of the document are detected by the edge detection unit based on the color image . Special document generally have a by four sides rectangular, often ink adheres to the vicinity of one of the sides of its four sides. Therefore, when the only one side of the document ink to detect whether or not attached, but might not ink even prohibited document is detected, since the detection for a plurality of sides in claim 6, more precisely There is an effect that it can be detected well. In the special document, ink is attached near the edge of the document, and the ink has a color such as blue or red, and the lightness value and the saturation value representing the color are detected by the color information detecting means . Mode since Nokuro from the image only lightness (luminance) is obtained, but not be this transgression identifying a chromatic color of the image and the achromatic image, such as saturation or hue is obtained from the color image, the average the saturation value, and the achromatic color of the image and the chromatic color of the image can identification be Rukoto. Since the determination unit performs the determination based on the average brightness value and the average saturation value, it can determine whether the document is a special document with higher accuracy than when determining whether the document is a special document based on the brightness. There is an effect.

The main scanning processing unit reads the original again as a monochrome image. If the determination unit determines that the document is a special document, the output unit changes the density value of each pixel constituting the monochrome image read by the scan processing unit so that the density is increased and outputs the changed value. To do. The image formed on the special document is often a thin image. However, according to the sixth aspect , the thin image is output after being changed so that the density is increased by the output means. There is an effect that it is possible to output at an appropriate density. Since the image is output at an appropriate density according to the type of document, the user does not need to manually set the apparatus to correct the density according to the type of document, which is convenient.

According to the image reading apparatus of the seventh aspect , in addition to the effect produced by the image reading apparatus of the fifth aspect , the brightness detection means is directed from the edge detected by the edge detection means to the edge side facing the edge. Then, the lightness value of the determination range is detected with the band-shaped range inside the width of about 3 mm and along the detected edge as the determination range. Then, based on the detected brightness value , it is determined whether the document is a special document. A special document often has ink such as carbon paper attached to the inside of a width of about 3 mm along one end of the document. By using an image in this range, it can be determined whether the document is a special document. Since this approximately 3 mm width is a very narrow range compared to the entire document, the determination process can be performed at a higher speed than when determining whether the document is a special document based on the image of the entire document. effective.

According to the image reading apparatus of the eighth aspect , in addition to the effect achieved by the image reading apparatus of the sixth aspect , the color information detecting means moves from the edge detected by the edge detecting means to the edge side facing the edge. The lightness value and the saturation value of the determination range are detected using the band-shaped range along the detected edge as the determination range inside the width of about 3 mm. Then, based on the detected brightness value and saturation value, it is determined whether or not the document is a special document. A special manuscript is often attached with ink such as carbon paper on the inside of a width of about 3 mm along one end of the manuscript, and by using an image in this range, it can be determined whether it is a special manuscript. Since this approximately 3 mm width is a very narrow range compared to the entire document, the determination process can be performed at a higher speed than when determining whether the document is a special document based on the image of the entire document. effective.

According to the image reading apparatus of the ninth aspect , in addition to the effect exhibited by the image reading apparatus according to any one of the fifth to eighth aspects, the pre-scan processing unit reads an image of the entire range of the document with a predetermined resolution. The image information storage means stores an image of the entire range of the document read by the prescan processing means. The edge detection unit detects a plurality of edges of the document based on the image stored by the image information storage unit, and the determination unit determines whether the document is a special document based on the image in the determination range along the detected edge. Judging. The main scan processing unit acquires a monochrome image by the image reading unit at a resolution higher than the reading resolution of the pre-scan processing unit. That is, since the pre-scan processing unit reads an image at a lower resolution than the main scan processing unit, it is possible to reduce the storage capacity of the image information storage unit and to perform reading at high speed. On the other hand, since the scan processing unit reads an image with a high resolution, it can output high-quality image information.

According to the image reading device of the tenth aspect , in addition to the effect produced by the image reading device according to the first or fifth aspect , the white pixel detecting means is a brightness value of the pixels constituting the image read by the image reading means. Detects white pixels that are greater than a predetermined brightness value. The lightness detection means calculates an average lightness value obtained by averaging the lightness values of the pixels in the determination range after excluding the white pixels detected by the white pixel detection means from the pixels constituting the image in the determination range . Near the edge of the special document, ink such as carbon paper is attached, but the amount thereof is very small, and most of the determination range is the ground color. Therefore, when the ground color is white, the average value of the brightness of the white pixels included in the determination range and the brightness of the portion to which the ink is attached is the average value of the brightness of the white pixels. It is difficult to determine whether or not ink is attached. According to the tenth aspect , since the average value of the brightness values of the remaining pixels excluding the white pixels among the pixels included in the determination range is calculated, the average value is different from the brightness of the white pixels. There is an effect that the special document can be accurately determined with a large value.

According to the image reading device of the eleventh aspect , in addition to the effect produced by the image reading device according to the first or fifth aspect , the ground color detecting means detects the ground color based on the image read by the image reading means. Then, the lightness detection means calculates an average lightness value obtained by averaging the lightness values of the pixels in the determination range after excluding the ground color pixels detected by the ground color detection means from the pixels constituting the image in the determination range. . Near the edge of the special document, ink such as carbon paper is attached, but the amount thereof is very small, and most of the determination range is the ground color. Therefore, most of the pixels in the determination range are pixels of the ground color, and when the lightness of the ground color and the lightness of the portion where the ink is attached are averaged, the average value is the value of the lightness of the ground color. It is difficult to determine whether or not ink is attached. According to the eleventh aspect , since the average value of the brightness of the pixels excluding the ground color pixels among the pixels included in the determination range is calculated, the average value is a value having a large difference from the brightness of the ground color. There is an effect that a special document can be accurately determined.

According to the image reading device of the twelfth aspect , in addition to the effect produced by the image reading device according to any one of the second, sixth , and eighth aspects, the white pixel detecting means can detect the color image read by the image reading means. A white pixel having a lightness value of a constituent pixel larger than a predetermined lightness value is detected. The color information detecting means removes the white pixels detected from the pixels constituting the image of the determination range, and then calculates an average lightness value and an average saturation value obtained by averaging the lightness value and the saturation value of the pixels in the determination range, respectively. that put out calculation. Near the edge of the special document, ink such as carbon paper is attached, but the amount thereof is very small, and most of the determination range is the ground color. Therefore, when the ground color is white, the average value of the brightness of the white pixels included in the determination range and the brightness of the portion to which the ink is attached is averaged, and the brightness value of the white pixels And the special document is difficult to judge. Similarly, when the saturation of the white pixels included in the determination range and the saturation of the portion to which the ink is attached are averaged, the difference between the average value and the saturation value of the white pixels is small. However, according to the twelfth aspect , the brightness values of the remaining pixels excluding the white pixels among the pixels in the determination range are averaged, and further white pixels are excluded. Since the saturation values of the remaining pixels are averaged, the difference between the brightness and the saturation of the white pixels is increased, and there is an effect that the determination can be made with high accuracy.

According to the image reading device of the thirteenth aspect , in addition to the effect produced by the image reading device according to any one of the second, sixth , and eighth aspects, the achromatic color pixel detecting means is a color image read by the image reading means. An achromatic pixel is detected based on the saturation value of the pixel that constitutes. The color information detecting means removes the achromatic color pixels detected by the achromatic color pixel detecting means from the pixels constituting the image of the judgment range, and then averages the brightness values and the saturation values of the pixels in the judgment range. that issue calculate the value and the average saturation value. Near the edge of the special document, ink such as carbon paper is attached, but dust or dirt may be attached, and these dust and dirt images are achromatic such as gray.

Therefore, the average value of the lightness and saturation of all the pixels included in the judgment range is the average value including the lightness and saturation of these achromatic pixels, and is the average when only ink is attached. Unlike the value, it cannot be determined with high accuracy. However, by calculating the average value of the brightness value and the saturation value of the pixels in the determination range excluding the achromatic color pixel, these dust and dirt This is advantageous in that it is possible to accurately determine whether the document is a special document.

According to the image reading apparatus according to claim 14, claim 2, in addition to the effects of the image reading apparatus according to any one of 6, 8, background color detection means, the color image read by the image reading means Based on this, the ground color is detected. If the background color of the document is a color other than white or gray and the background color is determined based on the monochrome image of the document, if the brightness is the same even if the document color and the ink color are different, the ink This pixel is also determined to be the ground color, but if it is determined based on the color image, the ground color and ink of the document can be identified.

The color information detecting means removes the ground color pixels detected by the ground color detecting means from the pixels constituting the image in the determination range, and then averages the brightness values and the saturation values of the pixels in the determination range. that issue calculate the value and the average saturation value. Near the edge of the special document, ink such as carbon paper is attached, but the amount thereof is very small, and most of the determination range is the ground color. Therefore, when the brightness of the ground color pixels included in the determination range and the brightness of the portion to which the ink is attached are averaged, the difference between the average value and the brightness value of the ground color pixels is reduced. It becomes difficult to judge special manuscripts. Similarly, the average of the saturation of the background color pixels included in the judgment range and the saturation of the portion where the ink is attached is the difference between the average value and the saturation value of the background color pixels. According to the fourteenth aspect of the present invention , the brightness values of the remaining pixels excluding the ground color pixels are averaged and further white pixels are obtained. Since the saturation values of the remaining pixels excluding the are averaged, the difference between the lightness and saturation of the ground color pixels is increased, and the determination can be made with high accuracy.

According to the image reading apparatus according to claim 15, wherein, in addition to the effects of the image reading apparatus according to any one of claims 12 to 14, the color information detecting unit, the hue values of pixels constituting an image of the determination range Pixels within a predetermined range are extracted, and the lightness value or saturation value of the extracted pixels is averaged to calculate an average lightness value or average saturation value. Near the edge of the special document, ink such as carbon paper adheres, and the color of the ink is a limited color such as blue or red. These colors can be identified by hue values. A hue range is set, and an average brightness value or an average saturation value is calculated for pixels whose hue value falls within that range. Thereby, there is an effect that it is possible to more accurately determine whether or not the ink adheres to the carbon paper.

According to the image reading processing program of the sixteenth aspect, the determination range for determining the type of document is provided on one end side in the direction perpendicular to the moving direction of the image reading means, and the image in the determination range Is read by the determination range processing step . The judgment step, when the document is determined to be a special document, the output step, the concentration of the density values of the pixels constituting the monochromatic image, and outputs the modified such that darker read.

The image formed on the special document is often a thin image. However, according to the sixteenth aspect , since this thin image is output so that the density is increased by the output step, it is output according to the type of the document. There is an effect that it is possible to output at an appropriate density. Since the image is output at an appropriate density according to the type of document, the user does not need to manually set the apparatus to correct the density according to the type of document, which is convenient. Further, since it is determined that the document is a special document based on an image in the determination range provided on one end side of the document, the determination process is performed as compared with the case where it is determined whether the document is a special document based on the image of the entire document. There is also an effect that it can be performed at high speed.

According to the image reading processing program of the seventeenth aspect, the determination range for determining the type of document is provided on one end side in a direction perpendicular to the moving direction of the reading unit, and the color image in the determination range. Is read by the determination range processing step . Special document, ink is attached near the end of the document, the ink has a color such as blue or red, and brightness value and the saturation value representing the color is detected. The determination step determines that the document is a special document when the average brightness value calculated by the color information detection step and the average saturation value are within a predetermined range. Since only the brightness (luminance) is obtained from the monochrome image, but not be this transgression identifying a chromatic color of the image and the achromatic image, saturation or hue is obtained from the color image, the saturation value allows the achromatic image and chromatic color image can identification be Rukoto. The determination means makes a determination based on the average brightness value and the average saturation value, and can determine whether the document is a special document with higher accuracy than when determining whether the document is a special document based on the brightness. effective.

If it is determined in the determination step that the document is a special document, the output step changes the density value of each pixel constituting the read monochrome image so as to increase the density. The image formed on the special document is often a thin image. However, according to claim 17 , since this thin image is output so that the density is increased by the output step, it is output according to the type of the document. There is an effect that it is possible to output at an appropriate density. Since the image is output at an appropriate density according to the type of document, the user does not need to manually set the apparatus to correct the density according to the type of document, which is convenient. Further, since it is determined that the document is a special document based on an image in the determination range provided on one end side of the document, the determination process is performed as compared with the case where it is determined whether the document is a special document based on the image of the entire document. There is also an effect that it can be performed at high speed.

According to the image reading processing program of the eighteenth aspect, a monochrome image of the entire range of the document is read by the pre-scan processing step, and a plurality of edges of the document are detected by the edge detection step based on the monochrome image. . Special document generally have a by four sides rectangular, often inks, such as carbon paper is adhered to the vicinity of one of the sides of its four sides. Therefore, in the case of detecting whether or not for only one side of the original ink is adhered, it may not be detected even special document, since the detection for a plurality of sides in claim 18, further There is an effect that detection can be performed with high accuracy. The determination step determines that the document is a special document when the average brightness value calculated by the brightness detection step is included in a predetermined range. Since the density of the ink is higher than the density of the background color of the original, if the ink is attached to the original, the brightness of the image of the portion where the ink is attached is lowered. Therefore, it is possible to determine whether or not the ink is attached by detecting the brightness value of the read image, and the determination unit determines that the original is a special document when the ink is attached.

In the main scan processing step, the original is read again as a monochrome image, and when the determination step determines that the original is a special original, the output step determines the density of each pixel constituting the monochrome image read in the main scan processing step. Change the value to increase the density and output. The image formed on the special document is often a thin image. However, according to claim 18 , since this thin image is output so that the density is increased by the output step, it is output according to the type of the document. There is an effect that it is possible to output at an appropriate density. Since the image is output at an appropriate density according to the type of document, the user does not need to manually set the apparatus to correct the density according to the type of document, which is convenient.

According to the image reading processing program of the nineteenth aspect, the color image of the entire range of the document is read by the pre-scan processing step, and a plurality of edges of the document are detected by the edge detection step based on the color image. . Special document generally have a by four sides rectangular, often ink adheres to the vicinity of one of the sides of its four sides. Therefore, when the only one side of the document ink to detect whether or not attached, but might not ink even prohibited document is detected, the claim 19, since the detection for a plurality of sides, more There is an effect that detection can be performed with high accuracy. In addition, special manuscripts are attached with ink near the edges of the manuscript, and the ink has a color such as blue or red, and the lightness value and the chroma value representing the color are detected by the color information detecting step. The The determination step determines that the document is a special document when the average brightness value and the average saturation value calculated by the color information detection step are included in a predetermined range. Since only the brightness (luminance) is obtained from the monochrome image, but not be this transgression identifying a chromatic color of the image and the achromatic image, saturation or hue is obtained from the color image, the color saturation value allows the achromatic image and chromatic color image can identification be Rukoto. The determination step makes a determination based on the average brightness value and the average saturation value, and can determine whether the document is a special document with higher accuracy than when determining whether the document is a special document based on the brightness. effective.

In the main scanning process step, the original is read again as a monochrome image. When the determination step determines that the document is a special document, the output step changes the density value of each pixel constituting the monochrome image read by the scan processing unit so that the density is increased and outputs To do. The image formed on the special document is often a thin image. However, according to the nineteenth aspect , the thin image is output so that the density is increased by the output step. There is an effect that it is possible to output at an appropriate density. Since the image is output at an appropriate density according to the type of document, the user does not need to manually set the apparatus to correct the density according to the type of document, which is convenient.

  Hereinafter, a preferred first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing an external configuration of a multifunction peripheral device (hereinafter abbreviated as “MFP (Multi Function Peripheral) or (Multi Function Printer)”) 1 according to an embodiment of the present invention. As shown in FIG. 1, the MFP 1 integrally includes a printer 2 provided at the lower part, a scanner 3 provided at the upper part, and an operation panel 4 provided on the front side of the scanner 3. A scanner function, a copy function, and a facsimile function.

  The MFP 1 is connected to a computer (not shown), and records an image or document on a recording sheet (recording medium) based on image data or document data transmitted from the computer, or an external device such as a digital camera. It is possible to record image data output from a digital camera connected to a recording sheet, or to load various storage media such as a memory card and record the image data stored in the storage medium on a recording sheet. It is.

  The scanner 3 is an original cover provided with an automatic document feeder (ADF) 7 for an original reading table 6 that functions as an FBS (Flatbed Scanner, hereinafter referred to as “FBS”). 8 is attached so that it can be opened and closed with a hinge on the back side as a fulcrum.

  The upper surface of the document reading table 6 is widely opened, and a platen glass is fitted into the opening. Inside the document reading table 6, the space for moving the image reading unit 3a (see FIG. 3), the image reading unit, and the like. A space for arranging a member for supporting 3a and a driving mechanism is secured.

  The ADF 7 transports the document from the document tray 9 to the document discharge tray 10 through the document transport path. The ADF 7 is provided with a document leading edge sensor (not shown) that detects the leading edge of the document when the document is taken in, and performs control of conveying the document with the leading edge of the document detected by the sensor as a reference position.

  The printer 2 is a so-called inkjet image recording apparatus that records an image on a recording sheet by selectively ejecting ink droplets based on image data read by the scanner 3 or image data input from the outside. (Inkjet recording apparatus). As described above, the printer 2 is disposed below the scanner 3.

  An opening 5 is formed on the front side of the MFP 1, in other words, on the front side of the printer 2. A paper feed tray 14 and a paper discharge tray 15 are provided in the opening 5 so as to be completely contained. The paper feed tray 14 and the paper discharge tray 15 are arranged in two upper and lower stages, the paper discharge tray 15 is provided in the upper stage, and the paper feed tray 14 is provided in the lower part.

  A horizontally long operation panel 4 is provided on the front side of the MFP 1 as shown in FIG. The operation panel 4 is for operating the printer 2 and the scanner 3 and includes various operation keys 40 and a liquid crystal display (LCD) 41 (hereinafter referred to as a display screen). This display screen 41 has two screens with an aspect ratio of 3: 4 arranged side by side and an aspect ratio of 3: 8.

  The user can input a desired command using the operation panel 4. When a predetermined command is input to the MFP 1, the operation of the MFP 1 is controlled based on the input information. The operation keys 40 provided on the operation panel 4 are provided with a cross key, a numeric keypad, and the like.

  A connection panel 70 is provided above the opening 5 of the printer 2. The connection panel 70 is provided with a USB terminal 71 on the left end side thereof. The USB terminal 71 is a connector terminal that communicatively connects the external device and the MFP 1 by making a USB connection with the external device. A slot portion 72 is disposed on the right end side of the connection panel 70. The slot portion 72 is provided with a plurality of card slots into which card type memories can be loaded. When a card-type memory is loaded in the card slot and image data is read from the loaded card-side memory, the read image data and information related to the image data are displayed on the display screen 41.

  FIG. 2 is a perspective view showing an appearance of the MFP 1 with the document cover 8 opened. As shown in FIG. 2, a document retainer 19 is provided on the back side of the document cover 8. The document retainer 19 is a plate-like member having at least one surface formed in white, and the white surface is fixed downward. The upper surface of the document reading table 6 is greatly opened, and a platen glass 12 is fitted into the opening. A document guide 16 is provided at one end of the upper surface of the platen glass 12 (on the left side in FIG. 2) so as to abut one side of the document when the document is placed on the upper surface of the platen glass 12.

  An image reading unit 3a (see FIG. 3) is built in the document reading table 6, and is provided so as to be reciprocally movable in the sub-scanning direction (X direction). Details of the image reading unit 3a will be described later. A direction (Y direction) perpendicular to the sub-scanning direction X is referred to as a main scanning direction.

  When the scanner 3 configured as described above is used as an FBS, the document cover 8 is opened and a document is placed on the platen glass 12, and then the document cover 8 is closed and the document is fixed. The document is fixed by being sandwiched between the platen glass 12 and the document holder 19. When a reading start command is input, the image reading unit 3a is scanned in the sub-scanning direction X along the back surface of the platen glass 12, and the image of the document is read.

  When the ADF 7 is used and the original is automatically conveyed and read, the original passes through the reading surface 13 on the original reading table 6 in the process of conveying the original by the ADF 7, moves to the lower side of the reading surface 13 and stands by. The image of the original is read by the image reading unit 3a. Such image reading by the ADF 7 is performed in a state where the document cover 8 is closed with respect to the document reading table 6.

  Next, an outline of the scanner 3 will be described with reference to FIG. FIG. 3 is a cross-sectional view schematically showing the configuration of the scanner 3 and is a front view of the MFP 1. As shown in FIG. 3, a platen glass 12 is fitted in the opening of the document reading table 6, and an image reading unit 3a is provided below the platen glass 12.

  The image reading unit 3a reads a document by the CIS method. The light source (LED) 3b for irradiating light, a light guide 3c for converging light on a reading portion of the document G, and the document G are reflected. A light guide 3d for condensing the reflected light on the image sensor 3e and an image sensor 3e for outputting a voltage according to the intensity of the received light along the main scanning direction Y. It is provided so as to be able to reciprocate in the scanning direction X.

  When the original G is placed on the upper surface of the platen glass 12 and the original reading button of the operation key 40 is pressed, the image reading unit 3a is conveyed to the reading start position of the original G, and reading of the original G is started. . First, the LED 3b is turned on and irradiated with light. The path of the light is changed by the light guide 3c, and the light is irradiated as irradiation light S toward the upper side of the image sensor 3e. Of the light reflected on the surface of the original G (platen glass 12), the reflected light R reflected toward the image sensor 3e is collected by the light guide 3d and received by the image sensor 3e. The image pickup device 3e is configured by a CMOS sensor or the like, and outputs a voltage value according to the intensity of received light. The voltage value is input to the ASIC 3f. The imaging element 3e is a plurality of elements arranged in a straight line (main scanning direction Y), and one element forms one pixel in one line of image data. When one line of the original G is read, the image reading unit 3a is conveyed by a predetermined amount in the sub-scanning direction X to read the next one line, and the next one line is read. This one-line reading and a predetermined amount of conveyance are repeated, and the entire area of the original G is read. The predetermined amount to be conveyed is set as appropriate according to the resolution set at the time of reading.

  The ASIC 3f is an integrated circuit designed to convert the voltage value input from each element of the image sensor 3e into 16-bit numerical data, and then perform various data corrections and output the data as image data. A pixel value corresponding to one element of the image sensor 3e is formed by a 16-bit numerical value. The image data output from the ASIC 3f is written into the image memory 23a of the RAM 23 (see FIG. 4) via a bus line 25 shown in FIG. 4 described later, and the image of the original G is stored as image data.

  Next, the electrical configuration of the MFP 1 will be described with reference to FIG. FIG. 4 is a block diagram showing an electrical configuration of the MFP 1. The MFP 1 includes a printer 2, a scanner 3, a CPU 21, a ROM 22, a RAM 23, a network control unit (hereinafter referred to as “NCU”) 31, a modem 32, an operation key 40, an LCD 41, a USB terminal 71, a slot unit 72, and an amplifier 73. The speaker 74 is mainly provided, and these are connected to each other via the bus line 25.

  The CPU 21 controls each unit connected by the bus line 25 according to fixed values and programs stored in the ROM 22 and RAM 23, control of each function provided in the MFP 1, and various signals transmitted / received via the NCU 31. Is. The ROM 22 stores various control programs 22a executed by the MFP 1, and a normal gamma table 22b and a gamma table 22c dedicated to carbon paper that are referred to when setting the image density by the control program 22a. It is a non-rewritable memory. As one of the control programs 22a, there is a program that reads an image of the original G by the scanner 3 and performs a copying process for printing. This copying process will be described later with reference to a flowchart shown in FIG.

  The normal gamma table 22b is a conversion table that does not change the pixel density value when printing is performed, and the carbon paper dedicated gamma table 22c is a conversion table that changes the pixel density value so that the density becomes higher. is there. Based on the image read by the scanner 3, it is determined whether or not the original G is a special carbon copied original. If it is determined that the original G is not carbon copied, a normal gamma table is used. If it is determined that the data has been converted by the carbon 22b and has been carbon-copied, the conversion is performed by the gamma table 22c dedicated to carbon paper, and printing is performed based on the converted density value of the pixel. A normal gamma table 22b and a gamma table 22c dedicated to carbon paper will be described later with reference to FIG.

  The RAM 23 is a rewritable memory for storing various data. The RAM 23 is provided with various memories such as an image memory 23a. The image memory 23 a is a memory that stores image data of a document read by the scanner 3. When determining whether or not the original G is a carbon copy, the pixel value (RGB) of the image read by the scanner 3 is stored in the image memory 23a and determined based on the pixel value. Is done.

  The NCU 31 performs operations such as sending a dial signal to a telephone network (not shown) and responding to a calling signal from the telephone network. The modem 32 modulates and demodulates image data via the NCU 31 and transmits it to a partner facsimile machine (not shown), and transmits and receives various procedure signals for transmission control. The USB terminal 71 is a known circuit for transmitting and receiving data via a computer and a USB cable (not shown). The amplifier 73 is used to ring a speaker 74 connected to the amplifier 73 and output a ringing tone or the like.

  Next, a method for detecting the original G read by the scanner 3, the image data of the read original G, and the edge of the original G will be described with reference to FIG. FIG. 5A is a plan view schematically showing the image reading unit 3 a of the scanner 3, the platen glass 12, and the document G placed on the platen glass 12. FIG. 5B is a cross-sectional view taken along line A-A ′ shown in FIG. FIG. 5C is a diagram schematically showing the entire image data read by the scanner 3.

  When the document G is read by the scanner 3, the entire area that can be read by the image reading unit 3a is read regardless of the size of the read document. Whether or not the edge of the document G is detected from the read image data, and the image in the band-like range (area) along the edge is inspected, whether or not the document G to be read is carbon-copied. Is judged.

  When the carbon-copy original G is carefully observed, in many cases, the ink transferred from the carbon paper adheres to the inside width of the original G about 3 mm from the respective edges of the four sides of the original G. . Many of the carbon papers are coated with ink such as blue or red, and inks of these colors are attached. Therefore, a band-shaped range along the edge is set as the determination range inside the edge of the document G, an image in the determination range is read, and it is determined whether ink is attached based on the image in the determination range. If the inks of these colors are attached, it is determined that the original is a carbon copied special document.

  First, a method for detecting the edge of the original G will be described. In the present embodiment, in order to make the explanation easy to understand, a case where image data for one original is temporarily stored in the image memory 23a will be described as an example.

  As shown in FIG. 5A, the document G is rectangular in the present embodiment, and is formed by the image recording portion P and a margin surrounding the image recording portion P. The document G is placed on the platen glass 12 so that the image recording portion P that is a reading surface is directed to the lower surface, and one side of the document G is parallel to the sub-scanning direction X. The document cover 8 is closed, and the document G is sandwiched and fixed between the platen glass 12 and the document presser 19. In the example of FIG. 5A, the original G is placed so that one side in the longitudinal direction thereof is parallel to the sub-scanning direction X. However, the original placed on the upper surface of the platen glass 12 is shown. In some cases, one side of the document is placed in contact with the guide 16.

  FIG. 5B is a cross-sectional view taken along the line AA ′ shown in FIG. 5A, and illustrates the case where the image reading unit 3a is moved to the positions of X0, X1, and X2. Yes. When the document reading button of the operation key 40 is pressed while the image reading unit 3a is waiting (not shown), the image reading unit 3a is conveyed to the document reading start position X0, and reading of the document G is started. Is done. At this position X0, since no document is placed on the upper part of the image sensor 3e, the light reflected by the surface of the document retainer 19 is read and stored as image data in the image memory 23a. When the image data for one line is read, the image reading unit 3a is conveyed by a predetermined amount in the sub-scanning direction X, and the next one line is read. This reading and conveyance are repeated.

  When the image reading unit 3a is conveyed in the sub-scanning direction X and conveyed to the position X1 corresponding to one edge of the original G, the image of the edge of the original G is read and stored as image data in the image memory 23a. The At this position X1, since the irradiation light S viewed from the front is angled so as to go to the upper left, the diffraction of light occurs at one end of the original G, and the reflected light R becomes stronger, and FIG. As shown at position X1, the image data is whiter than the image data of the document retainer 19 portion. Therefore, the edge of the document G can be identified by the difference in color.

  Further, when the image reading unit 3a is moved in the sub-scanning direction X of the document G and conveyed to the position X2 corresponding to the other edge of the document G, the image of the other edge of the document G is similarly read. At this position X2, since the irradiation light S is provided with an angle, light is diffracted at the edge of the original G, and the reflected light R becomes weak. As shown in the position X2 in FIG. The image data is blacker than the 19-part image data. Therefore, the edge of the document G can be identified by the difference in color.

  In addition, the direction of the irradiation light S of the image reading unit 3a shown in FIG. Therefore, when the image reading unit 3a reads the image of the original G from the position X1 to the position X2, the image corresponding to one edge (the upper side in FIG. 5) of the original G is shown in FIG. As shown in Y1 of FIG. 5, black image data is obtained, and an image corresponding to the other edge of the document G (lower side in FIG. 5) is white image data as shown in Y2 of FIG. 5C.

  Accordingly, by detecting black image data and white image data corresponding to the four edges (sides) of the original G, the four edges of the original G can be detected.

  Next, a determination range that is a detection position for detecting whether or not carbon paper ink is attached will be described with reference to FIG. The document G is rectangular, and the rectangular document G has four edges (or sides), and carbon paper ink is often attached along these edges. Therefore, a determination range is set along these four edges, an image in the determination range is read, and it is determined whether or not ink used for carbon copy is attached. However, when setting the determination range along the four edges, once the image of the entire range of the original G is read, it is determined whether or not it is a carbon copy, and then the entire range of the original G is again read. It is necessary to read and print a monochrome image. This method will be described later as a second embodiment.

  In the first embodiment, a determination range is set along only one edge of the four edges of the document G, and it is determined whether or not a carbon copy is made based on an image in the determination range. After that, when the remaining area (image area) of the original is a black-and-white image read and carbon-copied, the density is corrected with a gamma table 22c dedicated to carbon paper, and is not carbon-copied Performs a process of outputting to the printer 2 without correcting the density by the normal gamma table 22b. In this case, since the image of the original is read by one scan, the time can be shortened compared to the case of performing the scan twice.

  6, 7 and 8 are plan views showing a determination range setting method applied in the first embodiment and the second embodiment. 6 shows a reference setting method when setting the determination range in the main scanning direction Y, FIG. 7 shows a setting method of the length S in the main scanning direction Y of the determination range, and FIG. 8 shows sub-scanning. It is a top view which shows the method of setting the position of the determination range of the direction X. FIG.

  FIG. 6 shows various methods for setting the determination range in the main scanning direction Y. For the document G, the reading range is indicated by a broken line, the center line is indicated by a one-dot chain line, the sub-scanning direction is indicated by X, and the determination range is indicated by a belt-like rectangle. The length of the determination range in the main scanning direction Y is S, and the length from the reference position to the determination range is shown.

  FIG. 6A shows a method for setting the center of the reading position as a reference. The original G is placed on the scanner 3 at a predetermined position. Using the center of the original G placed at the predetermined position as a reference, as shown by a one-dot chain line in FIG. 6A, the length A is taken on both sides from the center, and the range is set as a determination range. In this method, the length S in the main scanning direction Y is set to 2 × A. This method is suitable when applied to the scanner 3 of the type in which the center of the original G in the main scanning direction Y is aligned with the center of the reading position. In the above example, the same length is set on both sides of the center, but different lengths may be set.

  FIG. 6B shows a method based on the end portion of the document guide 16 with which the document G is brought into contact. In this method, the position of the length B from the document guide 16 is one end, and the length of the determination range in the main scanning direction Y is S. This method is suitable for the scanner 3 of the type in which the document guide 16 is installed on the platen glass 12 on which the document G is placed.

  FIG. 6C shows a method for setting both sides of the reading range as a reference. The reading range is a range in the main scanning direction Y in which the image reading unit 3a can read an image. In FIG. 6C, the left end and the right end of the reading range are indicated by broken lines, the position of the length D from the reading range at the left end is the left end of the determination range, and the position of the length E from the right end of the reading range is the determination range. It is the method of making the right end of.

  FIG. 6D shows a method of detecting edges at both ends of the original G in the main scanning direction Y, and setting the determination range with reference to the centers of the detected edges at both ends. This is a method in which the range of the length F on both sides from the detected edge center is set as the determination range, and the length S in the main scanning direction Y of the determination range is set to 2 × F. In this way, the lengths may be equal on both sides or different lengths.

  FIG. 6E shows a method in which edges at both ends of the document G in the main scanning direction Y are detected and the detected edges are used as a reference. In this method, the position of the length C from the left edge of the detected original G is set as the left end of the determination range, and the position of the length H from the detected right edge of the original G is set as the right end of the determination range. Thus, the lengths from both ends may be different lengths or the same length.

  FIG. 6F shows a method of detecting the edges on both sides of the original G in the main scanning direction Y and setting the determination range when the detected edges are different from the end of the reading range. In the case of FIG. 6F, the left end of the reading range is inside the left edge of the detected document, and the right edge of the detected document is inside the right end of the reading range. Taking the center of the left edge of the document and the right edge of the document as a reference, taking the length I from the center to both sides, the range as the determination range, and the length S in the main scanning direction Y of the determination range as 2 × I Is the method. In the above example, the same length is set on both sides of the center, but different lengths may be set. In contrast to the case of FIG. 6F, when the left end of the original is inside the left end of the reading range and the right end of the reading range is inside the right end of the original, the reading is made as the left end of the original. Using the center of the right end of the range as a reference, the length of I on both the left and right sides is set as the determination range. In this way, the length may be equal on both sides from the center or different lengths.

  FIG. 6G shows the determination range in the case where edges on both sides of the original G in the main scanning direction Y are detected and the detected edges are different from the end of the reading range, as in FIG. In the case of this figure, the left end of the reading range is inside the left edge of the detected document, and the right edge of the detected document is inside the right end of the reading range. . In this case, using the left end of the reading range and the right edge of the document as a reference, the position of the length J from the left end of the reading range is set as the left end of the determination range, and the position of the length K is determined from the right edge of the document. It is a method of setting the right end of the range.

  Contrary to the case of FIG. 6G, when the left end of the original is inside the left end of the reading range and the right end of the reading range is inside the right end of the original, the left end of the original and the reading range The range length S from the position of the length J from the left end of the document to the position of the length K from the right end of the reading range is set as the determination range with the right end as a reference. Note that the lengths may be different from both sides as described above, or may be the same length.

  Next, a method for setting the range length S of the determination range in the main scanning direction Y will be described with reference to FIG. Also in FIG. 6, the size S in the main scanning direction Y of the determination range has been described, but a method other than the above will be described.

  FIG. 7A shows a method in which the same size as the width of the set paper size in the main scanning direction Y is set as the determination range. The paper size is selected by the user from standardized sizes such as A4 and B5, and the same size as the paper width is set as the range length S. In some commercially available printers and scanners, the user sets the paper size, and the length of the determination range is set according to the set size.

  FIG. 7B shows a method in which the determination range is a range narrower than the width of the set paper size in the main scanning direction Y. This is a method in which a range length S is set by a predetermined width L (eg, 2 cm) from both ends in the main scanning direction Y of the paper size set by the user. It may be set with an equal length from both ends, or may be set with a different length from each end. Alternatively, the sheet size may be set by a ratio (for example, 90%) to the width in the main scanning direction Y.

  FIG. 7C shows a method in which ear whites (for example, 3 mm) are set on both sides of the set paper size, and the inside of the ear white is used as the determination range. Some scanners 3 have a range that can be read depending on the model, in which ear whites are set on both sides of the set paper width, and the inner side of the ear white is set as a read range. It is a method to set as.

  FIG. 7D shows a method of setting the determination range further inside the reading range in the main scanning direction Y of FIG. Ear whites are set on both sides of the set paper size. In this method, the position M in length from the right end of the left ear white is the left end of the determination range, and the position N in length from the left end of the right ear white is the right end of the determination range.

  Next, a method for setting the determination range in the sub-scanning direction X will be described with reference to FIG. FIG. 8A shows a method for setting the position of the determination range based on the distance from one end of the detected original G (original front end position). This is a method in which a detected position of 3 mm from one end of the original G is set as the lower end of the determination range, and a predetermined width (1 to 2 mm) is set as a determination range from there to one end of the original G.

  When the document G is transported by the ADF 7, the determination range is set based on the leading edge of the document G detected by the document leading edge sensor provided in the ADF 7. When the document G is placed on the platen glass 12, the edge of the document is detected, and the determination range is set based on the detected edge. The lower end of the determination range is 3 mm from the leading edge of the original G, but it may be 2 to 3 mm.

  In FIG. 8B, when the document guide 16 is provided, the lower end of the determination range is set at a predetermined distance (3 mm) from one end of the document guide 16 on which the document comes into contact. A method of setting a predetermined width (1 to 2 mm) as a determination range is shown on the side. When the document guide 16 is used as a reference as in this method, if the document G is placed away from the document guide 16 by the user, the determination range may not be an appropriate position.

  Next, a method for determining whether or not the document G is copied using carbon paper based on the image in the determination range read by the scanner 3 will be described with reference to FIG.

  The image information in the determination range read by the scanner 3 is composed of an R value (red), a G value (green), and a B value (blue) for each pixel, and each value is a numerical value of 12 to 16 bits.

  The RGB values are converted into Lab values by referring to a table or the like. The L value is luminance (brightness), and the larger the L value is, the brighter it is and the smaller it is, the darker it is. Therefore, the density can be determined from the L value. Further, from the a value and the b value, the saturation value C can be obtained by the following mathematical expression (1) and the hue value H can be obtained by the following mathematical expression (2), and the hue can be determined using these values.

次に、判定を行う場合の判定対象とする画素を設定する方法について説明する。
第１の方法：読み取られた判定範囲の全ての画素を判定対象とする
明度により判定する場合は、判定範囲内に含まれる全ての画素の明度値Ｌを加算し、その和を画素の総数で除算することにより明度の平均値を求める。その明度値Ｌの平均値が、所定の範囲内であるか否かを判定する。

Next, a method for setting a pixel to be determined when performing determination will be described.
First method: All pixels in the read determination range are to be determined. When determining by lightness, the lightness values L of all pixels included in the determination range are added, and the sum is calculated as the total number of pixels. The average value of lightness is obtained by dividing. It is determined whether or not the average value of the lightness values L is within a predetermined range.

When judging by color, for each predetermined color (for example, blue or red), a range of hue values H is determined, and an average saturation value obtained by averaging the saturation values C of the pixels included in the range in each range is obtained. Ask. Then, it is determined whether or not the ink of that color is attached depending on whether or not each average saturation value is within a predetermined range set for each color.
Second method: The pixel excluding the white pixel is set as the determination target. Among the pixels in the read determination range, the white pixel having the lightness value L larger than the predetermined value is detected, and the detected pixel is excluded. The remaining pixels are determined.

  FIG. 9A schematically shows pixels in the determination range. A pixel A indicated by a white circle indicates a white pixel having a large lightness value L, and a pixel indicated by a black circle B is subjected to carbon copy. The pixel of the ink adhering to the case is shown. The white pixel A is a ground color pixel of the original whose background color is white, and as shown in this figure, the portion to which ink is attached is smaller than the ground color portion.

Therefore, the average value of the lightness values L of all the pixels included in the determination range is high, and the difference from the lightness value L of the ground color is small, so that it is difficult to determine whether ink is attached. Therefore, in the second method, the determination is made only by the pixel B indicated by a black circle except for the white pixel A having a large lightness value L among the pixels included in the determination range. When judging by the brightness value L, the brightness value L of only the pixel B excluding the white pixel A is added, and the sum is divided by the number of pixels to be judged, thereby obtaining the average value of the brightness values L. Find a certain average brightness. Whether or not the ink is adhered is determined based on whether or not the obtained average brightness value is within a predetermined range. When the number of remaining pixels excluding the white pixel A is smaller than a predetermined number, it is determined that ink is not attached, and an average value is obtained only when a predetermined number of pixels or more are targeted. You may do it.
Third Method Among the pixels in the read determination range, an achromatic color pixel having a saturation value C smaller than a predetermined value is detected, and the remaining pixels excluding the detected pixel are determined.

  FIG. 9B schematically shows the state of the pixels in the determination range. A pixel A indicated by a white circle is a ground white pixel having a large lightness value L, and a pixel D indicated by a gray circle. Indicates a pixel that is read when dust or the like adheres to the document G or sensor, and a pixel B indicated by a black circle indicates a pixel that has read the ink that has adhered when carbon copying is performed.

  Among the pixels in the determination range, pixels with a low saturation value are pixels that are read when the background color is white or gray, or pixels that are attached with dust, etc. Since it is a chromatic color, only pixels of attached ink remain when achromatic pixels are excluded.

Therefore, when an achromatic pixel having a small saturation value C of the pixel is detected and the determination is performed using the pixels excluding the detected achromatic pixel, the determination can be performed with higher accuracy. In this case as well, if the number of pixels to be determined is smaller than a predetermined number as a result of removing achromatic pixels, it is determined that no ink is attached, and a predetermined number or more of pixels are targeted. The average value may be obtained only when it becomes.
Fourth Method The background color of the original G is detected, and the pixels corresponding to the background color are excluded from the pixels in the read determination range, and the remaining pixels are set as determination targets. When the ground color is white, the determination target is set by the second method, and when the ground color is white or gray, the determination target is set by the third method. If it is other than white or gray, it is included in the determination target. Therefore, in the fourth method, the ground color is detected, and the detected ground color pixel is excluded from the determination target.

  As a method for detecting the ground color, the pixel having the highest frequency is detected as the ground color. As shown in FIG. 9C, a histogram is created with the hue value H on the horizontal axis and the number of pixels taking the hue value H for all pixels in the determination range. Then, the hue value H with the highest frequency is determined as the ground color.

  In the fourth method, the pixels having the hue value H of the ground color determined in this way are excluded, and the remaining pixels are set as determination targets. Thereby, determination can be performed with better accuracy.

  In any of the methods, when performing determination based on lightness, the lightness value L of the pixels to be determined is added, and the sum is divided by the number of pixels to be determined to average the lightness value L. Ask for. It is determined whether or not ink such as carbon paper is attached depending on whether or not the average value of the lightness values L is within a predetermined range.

  In the case of determination by color, the average saturation value obtained by adding the saturation values C of pixels whose hue value H of the pixel to be determined is a predetermined color (blue or red) and taking the average is a predetermined value. It is determined whether or not ink such as carbon paper is attached depending on whether or not it is within the range.

  When a determination range image is read as a monochrome image, the horizontal axis of the graph shown in FIG. 9C is used as the brightness value, and the histogram is created by summing up the number of pixels for each brightness value. High brightness may be the lightness of the ground color. That is, the determination range does not necessarily need to be read in color.

  Next, a method for increasing the density of image information read by the scanner 3 will be described with reference to FIG. Here, two methods will be described. First, one method is a method of increasing the density by converting the value of image information formed by multiple values (for example, 256 steps formed by 8 bits). In another method, halftone processing is performed when printing is performed, and the density is increased by controlling binary values in this halftone processing.

  First, a method for increasing the density using multiple values will be described with reference to FIGS. 10 (a) and 10 (b). The image in the determination range is determined by a color image. When printing is performed, a monochrome image is read and printing is performed based on the monochrome image. Each graph shown in FIG. 10 shows a gamma curve in which the horizontal axis represents the value of a pixel detected in the monochrome image as an input value, and the vertical axis represents an output value.

  FIG. 10A shows a gamma curve when the density is not changed, and this gamma curve is a straight line drawn on a diagonal line of the graph. This gamma curve is stored in the ROM 22 as a normal gamma table 22b.

  FIG. 10B is a gamma curve that is changed so as to increase the density as a whole. The curve is convex upward so that the density increases over almost the entire area of the straight line drawn on the diagonal line. This gamma curve is stored in the ROM 22 as a gamma table 22c dedicated to carbon paper. If it is determined that the original G is a special original copied using carbon paper, the pixel value is converted using the gamma curve shown in FIG. 10B, and printing is performed using the converted value. On the other hand, if it is determined that the original is not a special original copied using carbon paper, the pixel value is converted using the normal gamma curve shown in FIG. Printing is performed.

  Next, a method of increasing the density by binary will be described with reference to FIGS. 10 (c) and 10 (d). In an inkjet printing apparatus, an image is formed on a recording medium by controlling whether or not a small amount of ink is ejected for each pixel. In this case, the print information is multivalued, and whether to eject ink or not is set according to the value.

  The graph shown in FIG. 10C indicates that the ink is ejected when the input value is larger than A, and the ink is not ejected when the input value is smaller than A. Further, the graph shown in FIG. 10D indicates that the ink is ejected when the input value is larger than B, and the ink is not ejected when the input value is smaller than B. The value B is smaller than the value A. Since the input value is set to a small value, in the case shown in (d), ink is ejected in a wider range than in the case shown in (c), and the density becomes high.

  Next, the copying process executed by the CPU 21 will be described with reference to FIG. This copying process is described in the control program 22 a stored in the ROM 22. This processing is executed when the user instructs to print the original G on which an image is recorded in monochrome. In this process, first, the image reading unit 3a is moved to a determination range along one end of the original G, a color image in the determination range is read, and it is determined whether or not the original G is carbon copied from the color image. . After the determination is made, a monochrome image of the original G is read, and if it is determined by the determination that the original G is not carbon-copied, printing is performed as it is and it is determined that the original G is carbon-copied. In the case of printing, printing is performed with a high density.

  This will be described with reference to the flowchart shown in FIG. When the user places an original G on the opening of the original reading table 6 and operates to copy a monochrome image, first, white and black reference levels for monochrome and color are acquired. (S1). The scanner 3 includes a white reference plate. Before reading the image of the original G, the white reference plate is read by irradiating light on the white reference plate to read the image of the white reference plate. Without irradiating light, the white reference plate is read to obtain the black reference level.

  Next, the image reading unit 3a is moved to the leading end of the original G (S2). This leading edge is a position corresponding to the determination range, and in this embodiment, is a position moved approximately 1 mm inward from the leading edge of the document G. From this position, a color image having a width of 1 to 2 mm in the determination range is read while sequentially moving the image reading unit 3a (S3).

  Next, the RGB values of the pixels constituting the color image in the determination range are converted into Lab values, and the average brightness is calculated based on the brightness value L (S4). As described with reference to FIG. 9, this average brightness includes a method of averaging the brightness of all the pixels included in the determination range and a method of averaging the brightness values L of the pixels excluding the white pixels. Then, when calculated by each method, if it is a special document, a predetermined range that the average brightness value takes is preset, and it is determined whether or not the average brightness is within the predetermined range (S5). Here, the predetermined range defines a range in which the average brightness value can be obtained when the document is a special document, and is determined in advance based on experiments or the like and stored in the ROM 22.

  If the calculated average brightness is within a predetermined range (S5: Yes), the saturation value C of each pixel in the determination range is then calculated using the above equation (1), and the saturation value C The average saturation is calculated by averaging (S6). When calculating the average saturation, as described with reference to FIG. 9, a method of averaging the saturation values C of all the pixels in the determination range, or a background color pixel by detecting the background color of the document G There is a method of averaging the saturation values C of the pixels excluding.

  If there is a possibility that pixels of a plurality of types of colors exist in the document G, the hue of each pixel is acquired, and the saturation value C is averaged only for pixels in which the hue is in a predetermined range, so that the accuracy is improved. It is possible to determine whether the document is a special document. The predetermined range here also defines a range in which the hue value can be obtained when the document is a special document, and is determined in advance based on experiments or the like and stored in the ROM 22.

  For example, the original G is a carbon copy, and the ink on the carbon paper is blue, and the ink adheres to the judgment range, and the size is pressed using red vermilion, and the red vermilion adheres to the judgment range. In such a case, when the average saturation is calculated by averaging the saturation values C for the blue pixels and the red pixels, the average saturation is obtained even though the carbon paper ink is attached. May not fall within the prescribed range. Therefore, the blue pixel and the red pixel are divided by the hue value H, and the average saturation is calculated in each division. Then, a predetermined range is set for each category, and it is determined whether or not the average saturation value is within the range set for each category, and the average saturation of any category is within the predetermined range. If there is, it is determined that ink such as carbon paper is attached. By processing in this way, it is possible to determine whether or not ink such as carbon paper is attached with higher accuracy. The predetermined range here also prescribes the range that the average saturation value can take when the original is a special original, and is determined in advance based on experiments or the like and stored in the ROM 22.

  If the average saturation is calculated, it is then determined whether or not the calculated average saturation is within a predetermined range (S7). If the calculated saturation is within a predetermined range (S7: Yes) The original G is determined to be a carbon original special original, and is set to perform conversion using the gamma table 22c dedicated to carbon paper for increasing the density (S8).

  On the other hand, when the calculated average brightness is not within the predetermined range in the determination process of S5 (S5: No), or when the calculated saturation is not within the predetermined range in the determination process of S7 (S7: No), it is determined that the original G is not a carbon-copy special original, and the normal gamma table 22b whose density is not changed is set to perform conversion (S9).

  When the process of S8 or S9 is completed, the remaining area of the original G in the determination range is read as a monochrome image, the read pixel value is converted using the gamma table set in S8 or S9, and the converted pixel The printer 2 is instructed to send the value to the printer 2 for printing (S10).

  As described above, as described in the first embodiment, first, a determination range set within approximately 3 mm from one end of the original G is read as a color image, and the original G is carbon-copied based on the color image. It is determined whether the document is a document. This determination is made as a special document when the average brightness value obtained by averaging the brightness values L of the pixels in the image in the determination range and the average saturation value obtained by averaging the saturation values C are within a predetermined range, respectively. If the original is a special document, the density of the original read as a monochrome image is increased and output to the printer 2. Therefore, it can be appropriately determined that the original is a special document, and the thin original G that has been carbon-copied is printed darkly, and the printed image can be prevented from being thin and unclear.

  Next, a second embodiment will be described with reference to FIG. In the first embodiment described above, it is determined whether or not the original G is a carbon copy based on the color image in the determination range provided at one end of the original G. The remaining portion is read as a monochrome image, and the monochrome image is printed based on the read information. In the first embodiment, since determination and printing can be performed by one scan, there is an advantage that the processing time is short, but the determination is performed only on one end of the original G. Accuracy may be reduced.

  On the other hand, in the second embodiment, since the color image of the entire document G is first read and the determination range is set on the four sides of the document G to determine whether or not the carbon copy has been made, the determination accuracy is high. On the other hand, there is a disadvantage that it takes time for processing. Note that the second embodiment is different only in the copying process, and the other configuration is the same as that of the first embodiment, so that the description thereof is omitted.

  FIG. 12 is a flowchart showing a copy process in the second embodiment. The copying process will be described with reference to this flowchart. First, a pre-scan is performed. In this prescan, in order to read the color image of the original G set by the user with the scanner 3, the white reference value and the black reference value obtained by color reading are read (S11).

  Next, the color images of all the images of the original G are read, and the read image information is stored in the image memory 23a (S12). This image information is an RGB value of each pixel, and is a value normalized by the previously set white reference value and black reference value. This pre-scan is performed with a lower resolution than in the main scan. The resolution of the main scan is, for example, 600 dpi, and the resolution at the time of pre-scan is 100 dpi. By reducing the resolution, the amount of acquired image information is reduced, and the storage capacity of the memory for storing the image information can be reduced. Also, the time required for reading can be shortened.

  Next, the edge of the document G is detected based on the image data stored in the image memory 23a (S13). As described with reference to FIG. 5, since the image corresponding to the edge is a white or black straight line, the edge of the original G is detected by detecting this straight line. Next, a determination range of a band having a width of 1 to 2 mm along an edge approximately 1 mm inside from the detected edge is set (S14). This determination range setting method is one of the methods described with reference to FIGS.

  Next, the background color of the original G is detected. In this background color detection, as described with reference to FIG. 9C, for all the pixels in the determination range, the hue value H is the horizontal axis and the number of pixels having each hue value H is the vertical axis. A histogram is created, and the color indicated by the most frequently used hue value H is detected as the ground color (S15).

  Next, the pixels determined to be the ground color based on the hue value H of the pixels are excluded from all the pixels in the determination range, and the average lightness is calculated by averaging the lightness values L of the remaining pixels (S16). Next, it is determined whether or not the obtained average brightness value is within a predetermined range (S17).

  If the calculated average brightness is within the predetermined range (S17: Yes), next, the average saturation is obtained by averaging the saturation values C of the remaining pixels by removing the ground color pixels from all the pixels in the determination range. Is calculated (S18). If the average saturation is calculated, it is then determined whether or not the calculated average saturation is within a predetermined range (S19). If the calculated saturation is within a predetermined range (S19: Yes) The original G is determined to be a carbon original special original, and is set to perform conversion using the gamma table 22c dedicated to carbon paper for increasing the density (S20).

  On the other hand, when the calculated average brightness is not within the predetermined range in the determination process of S17 (S17: No), or when the calculated saturation is not within the predetermined range in the determination process of S18 (S19). : No), it is determined that the document G is not a carbon-copied special document, and the normal gamma table 22b whose density is not changed is used to perform conversion (S21).

  When the processing of S20 or S21 is completed, the monochrome white reference level and the black reference level are acquired (S22), the monochrome image of the entire original G is read again (main scan processing), and in S20 or S21 The read pixel value is converted using the set gamma table, and the printer 2 is instructed to transmit the converted pixel value to the printer 2 for printing (S23).

  As described above for the second embodiment, first, the entire color image of the document G is read at a low resolution by pre-scan processing, and the edges of the four sides of the document G are detected based on the color image. An image in a range of approximately 3 mm along the edge and inward from the edge is set as a determination range. When the average brightness and average saturation of the image in the determination range are within the predetermined ranges, it is determined that the document G is a special document. Next, a main scan is performed in which the entire original G is read again as a monochrome image. If the original is a special original, the density of the monochrome image read in the main scan is increased and output to the printer 2. The determination as to whether the document G is a special document is determined by the image in the band-shaped determination range along the inner side of the four sides of the document G, so that the determination is based on the determination range image along one side. Can be determined with high accuracy.

The determination range processing means according to each claim, the processing of the flowchart in S3 is true according to FIG. 11, the brightness detection hand stage, processing of S4 in the flowchart of described corresponds to Figure 11, the decision means Corresponds to the processing of S5 and S7 in the flowchart shown in FIG. 11, and the output means corresponds to the processing of S10 in the flowchart shown in FIG. Further, the color information detecting hand stage, processing of S6 in the flowchart correspond according to FIG. 11, the edge detection means, the processing in S13 of the flowchart described in FIG. 12 is applicable, prescan processing means, FIG. 12 The process of S12 of the flowchart described in FIG. 12 corresponds to this scan processing means, and the process of S22 of the flowchart described in FIG.

  Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications can be easily made without departing from the spirit of the present invention. It can be done.

  For example, in the above embodiment, the processing in the multi-functional peripheral device has been described. However, the processing may be performed in a single-function device such as a copying machine or a facsimile machine that includes the scanner 3.

  In the above embodiment, the image in the determination range is read as a color image, and it is determined whether the image is a special document based on the lightness, saturation, and hue of the pixels constituting the read image. Alternatively, the determination may be made based only on the luminance. In that case, the determination range may be read as a monochrome image. Further, since the determination range is highly likely to have carbon paper ink, it may be configured not to be used as print data at the time of copying.

  In the above embodiment, when calculating the average brightness value or the average saturation value, the average value of the pixels excluding the ground color pixels is calculated. However, the pixels excluding the ground color pixels are calculated. If the number is less than or equal to the predetermined number, it is not necessary to calculate the average value, and it may be determined that the document is not a special document.

  In the above embodiment, the average brightness value and the average saturation value are calculated, and it is determined whether or not the document is a special document depending on whether the value is within a predetermined range. A predetermined range is set for each of the degree C value and the hue H value, or a predetermined range is set for each of the L value, the a value, and the b value. It may be determined whether or not. In the case of carbon copying, carbon paper ink adheres, and the pixels of the image that has read the ink are considered to enter a limited area of the color space. Accordingly, when the number of pixels entering the area is large, it can be determined that the original is a special document. In the case of this method, RGB or a value representing a color space such as YCrCb may be used.

  In the above embodiment, the image information read by the scanner 3 and subjected to density adjustment is transmitted to the printer 2, but may be transmitted by facsimile or transmitted to a personal computer.

1 is a perspective view showing an external appearance of a multifunction peripheral device having an image processing device according to a first embodiment of the present invention. FIG. 3 is a perspective view showing an external appearance of a multifunction peripheral device in a state where a document cover is opened. It is sectional drawing of the front view which represented the structure of the scanner roughly. It is a block diagram which shows the electrical constitution of a multifunction peripheral device 5A is a plan view schematically showing an image reading unit and a document G placed on a platen glass, and FIG. 5B is a cross-sectional view taken along line AA ′ shown in FIG. FIG. 4C is a diagram schematically showing an image of a document read by a scanner. 4 is a plan view showing a position in a main scanning direction of a determination range set for a document G. FIG. 6 is a plan view showing a size in a main scanning direction of a determination range set for an original G. FIG. 6 is a plan view showing a position in a sub-scanning direction of a determination range set for a document G. FIG. It is a graph which shows the gamma table for changing a density | concentration. (A) And (b) is a figure explaining the pixel used as judgment object at the time of judging whether ink has adhered to the judgment range, and (c) is when detecting a ground color. This is a histogram created in It is a flowchart which shows a copy process. It is a flowchart which shows the copy process in 2nd Embodiment.

1 Multifunctional peripheral device (MFP)
2 Printer (output means)
3 Scanner 3a Image reading unit (image reading means)
21 CPU
22 ROM
23 RAM
23a Image memory (image information storage means)

Claims (19)

An image reading unit that reads at least a monochrome image; and a moving unit that relatively moves the image reading unit and the document. The reading operation by the image reading unit and the moving operation by the moving unit are repeated. In an image reading apparatus that reads a document,
A determination range processing unit that is provided on one end side of the document in the moving direction of the moving unit and that reads a determination range for determining the type of the document as a monochrome image using the image reading unit;
Brightness detection means for detecting the brightness value of the monochrome image in the determination range read by the determination range processing means and calculating the average brightness value by averaging the brightness values of the pixels in the determination range ;
A determination unit that determines that the document is a special document when the average brightness value calculated by the brightness detection unit is within a predetermined range;
When the determination unit determines that the document is a special document, an output unit that changes and outputs the density value of each pixel constituting the monochrome image read by the image reading unit so that the density is high An image reading apparatus comprising: An image reading unit that reads a document as a color image or a monochrome image, and a moving unit that relatively moves the image reading unit and the document, and the reading operation by the image reading unit and the moving operation by the moving unit are repeated. In the image reading apparatus for reading the document,
A determination range processing unit which is provided on one end side of the document in the moving direction by the moving unit and which reads a determination range for determining the type of the document with a color image using the image reading unit;
The brightness value and the saturation value of the color image in the determination range read by the determination range processing means are detected, and the average brightness value and the saturation value of the pixels in the determination range are averaged. Color information detecting means for calculating an average saturation value ;
Determining means for determining that the original is a special original when the average brightness value calculated by the color information detecting means is included in the predetermined range and the average saturation value is included in the predetermined range;
When the determination unit determines that the document is a special document, an output unit that changes and outputs the density value of each pixel constituting the monochrome image read by the image reading unit so that the density is high An image reading apparatus comprising: An edge detecting means for detecting one end of the document;
The determination range processing means has a band-like shape that is inside the width of about 3 mm from one end of the document detected by the edge detection means toward the other end side, and extends along one end detected by the edge detection means. the image reading apparatus according to claim 1 or 2, characterized in that the range is intended to read the image as the determination range. When the determination unit determines that the document is a special document, the output unit calculates the density value of each pixel constituting the image excluding the determination range from the monochrome image read by the image reading unit. the image reading apparatus according to claim 1, characterized in that the output to change to a concentration of darker 3. In an image reading apparatus provided with image reading means for reading a document at least as a monochrome image,
Pre-scan processing means for reading the entire range of the document as a monochrome image by the image reading means;
Edge detection means for detecting a plurality of edges of the document based on the monochrome image read by the pre-scan processing means;
A band-like range inside the document along a plurality of edges detected by the edge detection unit is set as a determination range, and a lightness value of the determination range is detected based on a monochrome image read by the prescan processing unit , Brightness detection means for calculating an average brightness value by averaging the brightness values of pixels within the determination range ;
Determining means for determining that the document is a special document when the average brightness value calculated by the brightness detection means is within a predetermined range;
A main scan processing unit that reads a monochrome image again by the image reading unit after the monochrome image is read by the pre-scan processing unit;
When the determination unit determines that the document is a special document, an output is output by changing the density value of each pixel constituting the monochrome image read by the main scan processing unit so as to increase the density. An image reading apparatus. In an image reading apparatus provided with image reading means for reading a document as a color image or a monochrome image,
Pre-scan processing means for reading the entire range of the original document with a color image by the image reading means;
Edge detection means for detecting a plurality of edges of the document based on the color image read by the pre-scan processing means;
Based on the color image read by the pre-scan processing unit, the band-like range inside the document along the plurality of edges detected by the edge detection unit is set as the determination range, and the brightness value and the saturation value of the determination range are determined. Color information detecting means for calculating the average brightness value and the average saturation value by averaging the brightness value and the saturation value of the pixels within the determination range ,
Determining means for determining that the original is a special original when the average brightness value calculated by the color information detecting means is included in the predetermined range and the average saturation value is included in the predetermined range;
A main scan processing unit that reads a color image by the pre-scan processing unit and then reads the original again as a monochrome image by the image reading unit;
When the determination unit determines that the document is a special document, an output is output by changing the density value of each pixel constituting the monochrome image read by the main scan processing unit so as to increase the density. An image reading apparatus. The lightness detection means is a band-shaped inner side having a width of approximately 3 mm from the edge detected by the edge detection means toward the edge facing the edge, and along the edge detected by the edge detection means. 6. The image reading apparatus according to claim 5 , wherein a brightness value of the determination range is detected using the range as a determination range. The color information detecting means is a strip-shaped inner side having a width of approximately 3 mm from the edge detected by the edge detecting means toward the edge facing the edge, and along the edge detected by the edge detecting means. The image reading apparatus according to claim 6, wherein the lightness value and the saturation value of the determination range are detected with the range as a determination range. Image information storage means for storing images of the entire range of the document read at a predetermined resolution by the prescan processing means;
The edge detection means detects a plurality of edges of the document based on the image stored by the image information storage means,
9. The image reading according to claim 5, wherein the main scanning processing unit acquires a monochrome image by the image reading unit at a resolution higher than a reading resolution of the pre-scan processing unit. apparatus. White pixel detecting means for detecting white pixels having lightness values of pixels constituting the image read by the image reading means being larger than a predetermined lightness value;
The lightness detection means calculates an average lightness value obtained by averaging the lightness values of the pixels in the determination range after excluding the white pixels detected by the white pixel detection means from the pixels constituting the image of the determination range. the image reading apparatus according to claim 1 or 5, characterized in that it also of that. A ground color detecting means for detecting a ground color based on the image read by the image reading means;
The lightness detection means removes the ground color pixels detected by the ground color detection means from the pixels constituting the image of the determination range, and then calculates an average lightness value obtained by averaging the lightness values of the pixels in the determination range. the image reading apparatus according to claim 1 or 5, characterized in that you also calculated for the a. White pixel detecting means for detecting white pixels having lightness values of pixels constituting the color image read by the image reading means being larger than a predetermined lightness value;
The color information detecting means removes white pixels detected by the white pixel detecting means from pixels constituting the image of the determination range, and then averages the brightness value and the saturation value of the pixels of the determination range. the image reading apparatus according to claim 2, 6, 8, characterized in that also that to calculate the average brightness value and the average saturation value of the is. Achromatic color pixel detection means for detecting achromatic pixels based on the saturation values of the pixels constituting the color image read by the image reading means,
The color information detection unit removes the achromatic color pixel detected by the achromatic color pixel detection unit from the pixels constituting the image of the determination range, and then determines the brightness value and the saturation value of the pixel in the determination range, respectively. the image reading apparatus according to claim 2, 6, 8, characterized in that also that to calculate the average brightness value was average and average saturation of the is. A ground color detecting means for detecting a ground color based on the color image read by the image reading means;
The color information detection means removes the ground color pixels detected by the ground color detection means from the pixels constituting the image of the determination range, and then determines the brightness value and the saturation value of the pixels of the determination range, respectively. the image reading apparatus according to claim 2, 6, 8, characterized in that also that to calculate the average brightness value was average and average saturation of the is. The color information detecting means extracts pixels whose hue values of pixels constituting the image in the determination range are within a predetermined range, and averages the brightness value or the saturation value of the extracted pixels, respectively. The image reading apparatus according to claim 12 , wherein the image reading apparatus calculates a value or an average saturation value. An image reading means capable of reading at least a monochrome image; and a moving means for relatively moving the image reading means and the original; a reading operation by the image reading means and a moving operation by the moving means; Is an image reading processing program that is executed in an image reading apparatus that reads the original by repeating
A determination range processing step that is provided on one end side of the document in the moving direction by the moving unit and reads a determination range for determining the type of the document as a monochrome image using the image reading unit;
A lightness detection step of detecting a lightness value of the monochrome image in the determination range read by the determination range processing step, and calculating an average lightness value by averaging the lightness values of the pixels in the determination range ;
A determination step of determining that the document is a special document when the average brightness value calculated by the brightness detection step is included in a predetermined range;
When the determination step determines that the original is a special original, an output step of changing and outputting the density value of each pixel constituting the monochrome image read by the image reading means so as to increase the density And an image reading processing program. An image reading unit that reads a document as a color image or a monochrome image, and a moving unit that relatively moves the image reading unit and the document, and the reading operation by the image reading unit and the moving operation by the moving unit are repeated. An image reading processing program executed in an image reading apparatus that reads the original,
A determination range processing step that is provided on one end side of the document in the moving direction by the moving unit and reads a determination range for determining the type of the document with a color image using the image reading unit;
By detecting the brightness value and the saturation value of the color image in the determination range read by the determination range processing step, and averaging the brightness value and the saturation value of the pixels in the determination range, respectively, the average brightness value and A color information detection step for calculating an average saturation value ;
A determination step of determining that the original is a special original when the average brightness value calculated by the color information detection step is included in a predetermined range and the average saturation value is included in the predetermined range;
When the determination step determines that the original is a special original, an output step of changing and outputting the density value of each pixel constituting the monochrome image read by the image reading means so as to increase the density And an image reading processing program. An image reading processing program executed in an image reading apparatus provided with an image reading unit capable of reading at least a monochrome image of a document,
A pre-scan processing step of reading the entire range of the document as a monochrome image by the image reading means;
An edge detection step for detecting a plurality of edges of the document based on the monochrome image read by the prescan processing step;
A band-like range inside the document along a plurality of edges detected by the edge detection step is set as a determination range, and a lightness value of the determination range is detected based on a monochrome image read by the prescan processing unit , A brightness detection step of calculating an average brightness value by averaging the brightness values of the pixels within the determination range ;
A determination step of determining that the document is a special document when the average brightness value calculated by the brightness detection step is included in a predetermined range;
A main scan processing step of reading the original again as a monochrome image by the image reading means after reading the original in the pre-scan processing step;
When the determination step determines that the original is a special original, the density value of each pixel constituting the monochrome image read by the main scan processing unit is changed so as to increase the output. And an image reading processing program. An image reading processing program executed in an image reading apparatus provided with an image reading means for reading a document as a color image or a monochrome image,
A pre-scan processing step of reading the entire range of the document with a color image by the image reading means;
An edge detection step for detecting a plurality of edges of the document based on the color image read by the prescan processing step;
Based on the color image read by the pre-scan processing means, the band-like range inside the document along the plurality of edges detected by the edge detection step is set as a determination range , and the brightness value and the saturation value of the determination range are determined. Detecting color information, and calculating an average brightness value and an average saturation value by averaging the brightness value and the saturation value of the pixels within the determination range, respectively ,
A determination step of determining that the original is a special original when the average brightness value calculated by the color information detection step is included in a predetermined range and the average saturation value is included in the predetermined range;
A main scan processing step of reading the original again as a monochrome image by the image reading means after reading the color image in the pre-scan processing step;
When the determination step determines that the original is a special original, the density value of each pixel constituting the monochrome image read by the main scan processing step is changed so as to increase the output. And an image reading processing program.

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