JPH06105091A - Photographing base type input device - Google Patents

Abstract

PURPOSE:To detect the size of a document to determine a photographic area by detecting a specific color like a flesh color of hands and figures from input information. CONSTITUTION:The document is photographed by a first photographing means (color CCD) 21 to obtain a picture element output of three colors of red, green, and blue. Photographed color data is sent to a flesh color area detecting circuit 44, and coloring matters of two specific colors are operated from the picture element output of three colors, and it is detected and discriminated whether the photographed picture element output has a specific color like a flesh color of hands and figures or not by these two coloring matters. The document is photographed by a second photographing means (photographing use CCD) 20, and the size of the document is discriminated by a signal processing circuit 101 based on the output of the flesh color area detecting circuit 44, and the size of the photographed document picture is corrected. That is, the flesh color as the specific color is detected to delete information of hands and fingers retaining the document, thereby obtaining a beautiful photographic area output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing table type input device for photographing a document such as a book from above.

[0002]

2. Description of the Related Art Conventionally, there has been known an apparatus capable of photographing a document such as a book from above with the document opened upward. Usually, in this type of apparatus, the operator has set the photographing range of the document. It should be noted that in an input device of a type in which a document is set face down on a document glass table and is photographed from below, a reflection type photo sensor is arranged below the document glass table so that the size of the document is automatically detected. However, such a configuration is difficult to apply to a type in which a document is set upward and the image is taken from above.

[0003]

By the way, in this type of apparatus, it is necessary to pay close attention to the shooting work so as to prevent the fingers holding the document and the fingers from entering the shooting area. Sometimes your finger or your finger is taken with the original and the shooting fails. The present invention solves the above-described problems, and by detecting a specific color such as a skin color of a hand / finger among input information, it is possible to detect the size of a document and determine a shooting area. An object is to provide a mold input device.

[0004]

In order to achieve the above object, the present invention takes an image of a document placed on a document table,
A first image pickup means for obtaining pixel outputs of the three colors of green and blue, a calculation means for calculating chromaticity of specific two colors from the imaged pixel outputs of the three colors of red, green and blue, and these two Based on the output of the discriminating means, the discriminating means for discriminating whether or not the pixel output captured based on the chromaticity is a specific color, the second image capturing means for photographing the document, and the second image capturing means It is an imaging stand type input device provided with a correction means for correcting the output.

[0005]

According to the above structure, the chromaticity (R, G) of two specific colors, for example, red and green, is calculated from the pixel outputs (r, g, b) of the three colors of red, green and blue. From this, specific color information, such as the skin color of the hand / finger, is detected and determined. It is possible to detect the size and the like of the document based on this discrimination output, and appropriately correct the size and the like of the captured document image based on this information.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an external configuration of a photographing table type document input device 1. The apparatus 1 includes a document table 3 on which a document is placed, an image pickup section 2 arranged above the document table, a buzzer 4 for issuing an alarm when an abnormality occurs, and a display for temporarily displaying an image of the document to be captured. 5, operation switch 6,
It is composed of a foot switch 7, a printer 8 that prints out an input image, a signal processing unit 9, and a storage device 10 that stores the input image information. The document placed on the document table 3 is photographed by the imaging unit 2 when the operation switch 6 is turned on. The photographed image can be printed on the printer 8 after being converted into an electrical symbol and sent to the signal processing unit 9 for appropriate processing, and can also be recorded on the storage device 10.

FIG. 2 shows an optical path of an image pickup system including a sensor unit and a lens housed in the photographing unit. The sensor unit 11 includes a line sensor for image pickup and a line sensor for skin color detection, which is formed of a CCD or the like, and a lens 12. This sensor unit 11
The area 13 can be photographed by scanning in the direction of the arrow in the figure.

FIG. 3 shows a state in which the original table is photographed from directly above. A document 14 is placed in the photographable area 13 on the document table. A document size detection sensor 15 is provided at the center of the imageable area 13 on the document table. Manuscript 1
4 is placed with its upper end aligned with the upper end of the photographable area 13 and with its center aligned with the document size detection sensor 15, and is held by the operator's hand 16. The document size detection sensor 15 is composed of an SPC array or the like, and the light incident on the SPC is blocked at the portion where the document 14 is placed. Therefore, by checking the output of each SPC, the document in the main scanning direction can be detected. I know the size. On the other hand, the size of the document in the sub-scanning direction can be known by detecting whether or not a part of the hand is included in each line in the sub-scanning direction. That is,
A range that does not include any part of the hand 16 is the document range in the sub-scanning direction.

FIG. 4 shows the structure of the sensor section 11. The monochrome line CCD 20 for photographing and the color line CCD 21 for skin color detection are separated by a distance l in the sub-scanning direction from the substrate 22.
They are arranged in parallel above. The substrate 22 is driven in the sub scanning direction. In the monochrome CCD 20, D1 to D
w is a dark output monitor pixel, and Y1 to Yx are shooting pixels. In the color CCD 21, Dc1 to Dcu are dark output monitor pixels, g1 to gv, b1 to bv, and r1 to rv.
Are green, blue and red pixels, respectively. Figure 5 shows CCD2
The states of 0 and 21 scans are shown. The CCDs 20 and 21 scan to photograph the shaded portions 23 and 24 through the lens 12. Since the CCDs 20 and 21 are installed in parallel at a distance l, the photographing portions 23 and 24 are also separated by the distance L. Further, since the CCDs 20 and 21 scan in the arrow direction, the photographing parts 23 and 24 move in the arrow direction.

Next, the processing configuration and the flow of processing of image data photographed by the photographing monochrome line CCD 20 will be described with reference to the block diagrams of FIGS. 6 to 8. CCD2
The image data of 0 is read out in the order of the dark output monitor pixels D1 to Dw and the imaging pixels Y1 to Yx, and one of the outputs of the dark output monitor pixels D1 to Dw that is read first.
Is determined and held in the sample hold (S / H) circuit 30 to determine the dark output level. Next, the shooting pixel Y
1 to Yx are sequentially read and input to the differential amplifier 31 together with the previously determined dark output level, and only the true signal component is amplified and output. The analog output of the differential amplifier 31 is input to the A / D converter 32, converted into digital data, and latched by the latch circuit 33.

This latch data is sent to the multiplier 35. The shading correction coefficient for each pixel of the CCD 20 is stored in the ROM 34, and is provided to the multiplier 35. As a result, the data from the latch circuit 33 is shading-corrected in the multiplier 35. The shading-corrected data is passed through the latch circuit 36 and is subjected to γ-conversion in a γ-conversion circuit 37 so as to be suitable for background removal and electrophotographic output. The γ-converted output is input to the logarithmic conversion circuit 39 via the latch circuit 38. The logarithmic conversion circuit 39 logarithmically converts the data of the CCD 20 into reflection density data. The data converted into the reflection density is sent to the main scanning direction correction circuit 42 via the latch circuit 40. The document size detection circuit 41 is a circuit for detecting the document size in the main scanning direction based on the output of the document size detection sensor 15 of FIG. 3, and the detection result is sent to the main scanning direction correction circuit 42. The correction circuit 42 corrects the image data from the latch circuit 40 based on the output from the document size detection circuit 41. The contents of the correction include, for example, replacing all the image data corresponding to the area outside the document in the main scanning direction with data corresponding to white.

The data from the main scanning direction correction circuit 42 is sent to the flesh color region correction circuit 45 via the latch circuit 43.
The skin color region detection circuit 44 will be described in detail later, but
The detection circuit 44 detects the skin color area in the photographing area, and the detection result is sent to the skin color area correction circuit 45.
The correction circuit 45 corrects the image data from the latch circuit 43. The contents of the correction include, for example, replacing all the image data corresponding to the skin color area with data corresponding to white, or if there is at least one pixel corresponding to the skin color area for each line in the sub-scanning direction, the entire data of that line is It is like replacing it with data corresponding to white. The output from the flesh color area correction circuit 45 is stored for two lines in the line buffers 46 and 47. The outputs of the skin color area correction circuit 45 and the line buffers 46 and 47 are input to the 3 × 3 filter 48. Same filter 48
Then, so-called MT such as edge enhancement or smoothing
Perform F correction. The data subjected to the MTF correction by the filter 48 passes through the latch circuit 49 and the laser beam printer (L
It is sent to the BP) controller 50 and printed.

Next, the principle of skin color detection will be described.
The red, green, and blue outputs from the color CCD 21 are r,
If g and b are used, the chromaticities R and G of red and green can be obtained by the following equations. R = r / (r + g + b) G = g / (r + g + b) FIG. 9 shows a flesh color region (hatched portion) and a white paper region (dot portion) on the RG chromaticity diagram. As is clear from FIG. 9, the areas of skin color and white paper do not overlap on the RG chromaticity diagram. Therefore, by converting the output data from the color CCD 21 into R and G chromaticity data and checking whether the values are within a proper range, it is possible to know whether the data is flesh color.

The specific structure and method of skin color detection will be described below with reference to the block diagrams of FIGS. In this embodiment, the flesh color is determined for each block with 6 pixels of red, green and blue as one block. Therefore, the chromaticities Rn and Gn of the nth block are calculated by the following equations.

[Equation 1]

Here, n = 1, 2, 3, ... V. The output data of the CCD 21 includes pixels Dc1 to Dcu,
g1, b1, r1 to gv, bv, and rv are read in this order. First, one of the pixels Dc1 to Dcu read out first is held in the sample hold (S / H) circuit 60, and the dark output level is determined. Next, the pixels g1, b1,
r1 to gv, bv, and rv are sequentially read, and the selector 6
When it is 1, it is input to the differential amplifiers 62 to 64 for each color. The differential amplifiers 62 to 64 amplify the difference between the dark output held in the S / H circuit 60 and the color output from the selector 61, and output a true signal component to the selector 65. Selector 6
The outputs from the amplifiers 62 to 64 are sequentially selected at 5 and input to the A / D converter 66. The color data converted into digital data by the A / D converter 66 is latched by the latch circuit 67.

The data latched in the latch circuit 67 is sent to the multiplier 69. In the ROM 68, the CCD 21
The shading correction coefficient for each pixel of is stored,
It is given to the multiplier 69. As a result, the data sent from the latch circuit 67 in the multiplier 69 is shading-corrected. The data from the multiplier 69 is latched by the latch circuits 70 to 75 for each data. That is, r (2
n-1) is in the latch 70, r2n is in the latch circuit 71,
g (2n-1) is in the latch circuit 72, g2n is in the latch circuit 73, b (2n-1) is in the latch circuit 74, and b2n.
Are respectively latched by the latch circuit 75. Where r,
The letters “g” and “b” and the parentheses after that are notations for the sake of convenience, and are equivalent to those shown in the above mathematical expression 1. This is achieved by controlling the latch enable pulse input to each latch circuit. The data latched by the latch circuits 70 to 75 are sent to the adders 76 to 78 and added for each color. The addition results of red and green are respectively latch circuits 79 and 8.
Latched to 0.

The outputs from the adder 78 and the latch circuit 80 are input to the adder 81, and the green and blue outputs are added. Further, the result and the output of the latch circuit 79 are input to the adder 82, and the red output is added. Adder 82
Then, the addition of all 6 pixels is completed, and the result is the latch circuit 8
It is input to the ROM 84 via the data item 3. The ROM 84 outputs the reciprocal of the input data, and this output is sent to the multiplier 86 via the latch circuit 85. The other input of the multiplier 86 is the latch circuits 79 and 8
With the output of 0, the output enable pulses of the latch circuits 79 and 80 are controlled and separately input to the multiplier 86. Multiplier 8
The chromaticities Rn and Gn are calculated at 6, and the results are sent to the latch circuits 87 and 88 for each color, and the comparators 90 and 91 are respectively provided.
Entered in.

The comparison data of the comparators 90 and 91 are stored in the ROM.
It is stored in 89. The comparators 90 and 91 determine whether or not each color-specific data is within the skin color area, and if it is within the area, output high (true). Comparators 90, 9
The output of 1 is logically ANDed by the AND circuit 92, and as a result, it is output as High if the block being calculated is flesh color, and is output as Low otherwise. The output of the AND circuit 92 is stored in the line buffers 93 and 94 for two lines. The outputs of the AND circuit 92 and the line buffers 93 and 94 are nine 3 × 3 filters 95-1 to 9-9.
Input to 5-9 and filtered. This filtering process corrects misjudgment, and is particularly for misjudgment in the vicinity of the boundary between the flesh-colored portion and the other portion on the document.

13 and 14 show a method of correcting the above-mentioned misjudgment. The shaded area indicates a skin color block. If the flesh color information of the eight blocks around the central block corresponds to at least one of the eight types in FIG. 13, the central block is determined to be the flesh color block.
On the other hand, as shown in FIG. 14, if the surrounding 8 blocks are not skin color blocks, the central block is not a skin color block.

Returning to FIG. 12 again, the outputs of the filters 95-1 to 95-9 are set to High if the block being operated is flesh color, and set to Low otherwise. Then, the logical sum is taken, and the final result of skin color discrimination is obtained. The output of the OR circuit 96 is temporarily stored in the buffer 97, and is output to the skin color region correction circuit 45 at an appropriate timing. In the above embodiment, the color CCD 21 scans first, and the photographing CCD 20 scans the same portion with a slight delay. Therefore, since the skin color information is always obtained first, the photographed data can be corrected in real time.

FIG. 15 shows a block configuration of an embodiment in which a warning is issued when a hand or a finger is placed on the image area. In FIG. 15, the image data photographed by the photographing CCD 20 is sent to the printer 103 via the signal processing circuit described in FIGS. On the other hand, the color data photographed by the color CCD 21 is sent to the skin color area detection circuit 44 described with reference to FIGS. 10 to 12, the skin color area is detected, and the result is sent to the signal processing circuit 101. Also, color C
The data of the CD 21 is also sent to the image area detection circuit 100.

When a character original is assumed as the original, r,
An area in which the outputs g and b are substantially equal and the output value is small (the luminance is low) means that the original is black, that is, the portion of the character. Therefore, the image area detection circuit 100 detects whether or not there is a character area as described above for each line in the sub-scanning direction. The detection results of the skin color area and the character area are sent to the area overlap determination circuit 102. Same determination circuit 1
In 02, it is judged whether or not both areas overlap,
If they overlap, the buzzer 4 is sounded to warn the operator. As a result, it is possible to prevent the image portion in the document from being pressed by hand. The warning is not limited to the buzzer but LED
May be made to shine.

The present invention is not limited to the configuration of the above embodiment, and various modifications can be made. For example, the color CCD 21 and the photographing CCD 20 do not necessarily have to have the same optical system, and it suffices that the positional relationship between the photographing regions of both CCDs is known. Both CCDs are not limited to line sensors and may be multi-line or area type sensors. The color CCD 21 may be of a three-plate type or a filter switching type, as long as it can output r, g, and b.

It is also possible to cover the hand or finger of the operator's original with gloves of a specific color or finger sack, and detect the hand or finger based on the chromaticity value. By doing so, it is possible to prevent erroneous recognition that occurs when a document having a chromaticity value close to skin color is photographed. Also, color CC
Instead of D, an infrared line sensor may be used to detect infrared rays emitted by the human body to detect hands and fingers. As a result, it is possible to prevent erroneous recognition at the time of photographing such as photographs and color printing.

[0025]

As described above, according to the present invention, when the original is photographed from above, the image pickup output is corrected based on the detection result of the specific color. By detecting the skin color of, the information of the hand / finger holding the document can be deleted and a beautiful output can be obtained. Also,
The input area can be changed by detecting the size of the effective area even for a document of an arbitrary size. Further, by covering unnecessary portions of the document with hands and fingers, the information can be erased.

[Brief description of drawings]

FIG. 1 is an external view of a shooting table type document input device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an optical path of a sensor unit and an image pickup system housed in a photographing unit of the apparatus.

FIG. 3 is a diagram showing a state at the time of shooting when the document table is viewed from directly above.

FIG. 4 is a diagram showing a configuration of a sensor unit.

FIG. 5 is a diagram showing how a CCD is scanned.

FIG. 6 is a block configuration diagram for processing image data photographed by a photographing CCD.

FIG. 7 is a block configuration diagram of the same.

FIG. 8 is a block configuration diagram of the same.

FIG. 9 is a diagram showing a skin color region and a white paper region on the RG chromaticity diagram.

FIG. 10 is a specific block configuration diagram for skin color detection.

FIG. 11 is a block configuration diagram of the same.

FIG. 12 is a block configuration diagram of the same.

FIG. 13 is a diagram showing a method of correcting misjudgment.

FIG. 14 is a diagram illustrating a method of correcting misjudgment.

FIG. 15 is a block diagram of an embodiment in which a warning is issued when a hand or a finger is placed on an image area.

[Explanation of symbols]

20 Monochrome line CCD for image pickup (second image pickup means) 21 Color line CCD for skin color detection (first image pickup means) 44 Skin color region detection circuit 45 Skin color region correction circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Satoyuki Nakamura 2-33 Azuchi-cho, Chuo-ku, Osaka City Osaka International Building Minolta Camera Co., Ltd. (72) Atsushi Mizuguchi 2-chome, Azuchi-cho, Chuo-ku, Osaka-shi 3-13 No. 13 Osaka International Building Minolta Camera Co., Ltd.

Claims (1)

[Claims] 1. A document placed on a platen is photographed and red,
A first image pickup means for obtaining pixel outputs of the three colors of green and blue, a calculation means for calculating chromaticity of specific two colors from the imaged pixel outputs of the three colors of red, green and blue, and these two Based on the output of the discriminating means, the discriminating means for discriminating whether or not the pixel output captured based on the chromaticity is a specific color, the second image capturing means for photographing the document, and the second image capturing means An imaging stand type input device comprising: a correction unit that corrects an output.