JPH05344342A - Image reader - Google Patents

Abstract

(57) [Summary] [Purpose] An image that reads a color image drawn with a plurality of specified color inks and generates a plurality of binary image data separated for each image portion of a plurality of different colors. Providing a reader. A CCD 1 of an image reading apparatus of the present invention converts reflected light or transmitted light from a document into a signal voltage 3 for each pixel. The reference voltage setting circuit 8 sets a reference voltage range corresponding to the signal voltage 3 of each color portion of the image drawn with the designated color ink on the document to be separated. The binarization circuits 4, 5, 6, and 7 binarize the signal voltage 3 depending on whether the signal voltage 3 is in the reference voltage range or not, and convert a predetermined color portion of the image on the document to another color. Binary image data separated from the part is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus for reading an image drawn with a plurality of designated color inks by separating the image into respective color portions.

[0002]

2. Description of the Related Art Conventionally, in order to obtain image data separated into respective color portions from an image drawn with a plurality of color inks, a color image reading device uses light sources of three colors of red, green and blue. Using a combination of a white light source and any one of red, green, and blue color filters and photoelectric conversion means, the reflectance or transmission of light of red, green, and blue with respect to each pixel of the image drawn on the original document. The color of each pixel of the image drawn on the original is read as a combination of the ratio data and separated for each color area, or each color is manually extracted from the color original using carbon paper or the like. That is, a plurality of originals in which the areas of FIG.

[0003]

However, since the former color image reading apparatus has a complicated structure, the manufacturing cost is high. Furthermore, when trying to obtain binary data in which only an image portion of a specific color is separated from the image on the document or when obtaining binary data for each portion of images of different colors, It was necessary to take in the image data generated by the color image reading device to a personal computer or the like, select pixels of a predetermined color by image processing, and generate new binary image data.

Further, the latter manual method requires complicated work and a lot of time to prepare a plurality of originals in which regions of respective colors are copied, and a monochrome image reading device requires a plurality of operations. It was difficult to precisely position each document when reading the document.

The present invention has been made to solve the above-mentioned problems, and separates only an image portion of a specific color from an image on a document without using an additional device or a plurality of different colors. It is an object of the present invention to provide an inexpensive image reading device which can directly obtain a plurality of image data separated for each image portion.

[0006]

To achieve this object, an image reading apparatus of the present invention is an image reading apparatus which divides an image on a document into a plurality of pixels and generates a digital signal for each pixel. An image forming means for forming an image of reflected light or a transmitted light from the original on the photoelectric converting means, and a photoelectric converting means for converting the original image formed by the image forming means into a signal voltage corresponding to the amount of incident light. , Reference voltage setting means for setting three or more reference voltage ranges different from each other, and binarizing means for binarizing the signal voltage depending on whether or not the signal voltage is in the reference voltage range.

[0007]

The photoelectric conversion means of the image reading apparatus of the present invention having the above structure converts the reflected light or the transmitted light from the document into a signal voltage for each pixel. The voltage range setting means sets a reference voltage range corresponding to the signal voltage of each color portion of the image drawn with the designated color ink on the document to be separated. The binarizing means binarizes the signal voltage according to whether the signal voltage is in the reference voltage range or not, and separates a predetermined color portion of the image on the original from a portion of other density and is binary image data. To generate.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, the configuration of the electronic circuit of the image reading apparatus of this embodiment will be described with reference to FIG. The electronic circuit of the image reading device comprises a well-known CCD 1, an amplifier circuit 2, binarization circuits 4, 5, 6, 7 and a reference voltage setting circuit 8. The connection between the components of this electronic circuit will be described. The CCD 1 is composed of a plurality of pixels arranged in a line, and outputs a voltage according to the amount of light received when each pixel receives the reflected light from the document, and the output of each pixel is an amplifier circuit. It is entered in 2. The output of the amplifier circuit 2 is input to the binarization circuits 4, 5, 6, 7. Further, among the reference voltages 9, 10, and 11 output from the reference voltage setting circuit 8, the reference voltage 9 is input to the binarization circuit 4, and the reference voltages 9 and 10 are input to the binarization circuit 5 for reference. The voltages 10 and 11 are input to the binarization circuit 6,
The reference voltage 11 is input to the binarization circuit 7.

Next, the operation of the components of the electronic circuit will be described. Each pixel of the CCD 1 is arranged such that an image on a document (not shown) is formed on each pixel by a lens (not shown), and the CCD 1 sequentially generates a voltage proportional to the amount of light irradiated to each pixel. Output. The amplifier circuit 2 amplifies the voltage and outputs 0 V as the signal voltage 3 when the CCD 1 does not receive light, and the signal voltage 3 increases as the light amount increases, and when the maximum light amount is received, the signal voltage 3 is output. It is set to output 2V. The reference voltage setting circuit 8 generates reference voltages 9, 10, and 11. At this time, the reference voltage 9 is 1.5 V and the reference voltage 10
Is set to 1.0V and the reference voltage 11 is set to 0.5V. The binarization circuits 4, 5, 6, 7 binarize the signal voltage 3 by comparing the reference voltage input to each with the signal voltage 3.

Next, an embodiment of the reference voltage setting circuit 8 will be described with reference to FIG. Resistor 1 having the same resistance value
4, 15, 16, and 17 are connected in series, and the resistor 1
+ 2V is applied to the end on the 4 side, and the end on the resistor 17 side is grounded. As a result, 1.5V is applied to the connection point between the resistors 14 and 15, and 1.V is applied to the connection point between the resistors 15 and 16.
0V, 0.5V is generated at the connection point between the resistors 16 and 17.

Next, an embodiment of the binarization circuit 4 will be described with reference to FIG. The signal voltage 3 is input to the non-inverting input of the comparator 20 having an open collector output, the reference voltage 9 is input to the inverting input, and the output is pulled up to +5 V by the resistor 21. With this configuration, when the signal voltage 3 is higher than the reference voltage 9, the output 22 of the comparator 20 becomes 5V, and when the signal voltage 3 is lower than the reference voltage 9, the comparator 2
The output 22 of 0 becomes 0V. That is, a pixel of a color whose signal voltage 3 obtained by amplifying the voltage generated by the pixel receiving the reflected light from the original document by the amplifier circuit 2 is larger than 1.5 V has a pixel of 5 V and a pixel of another color. It is separated to 0V and binarized.

Next, an embodiment of the binarization circuit 5 will be described with reference to FIG. The signal voltage 3 is input to the inverting input of the open collector output comparator 23, the reference voltage 9 is input to the non-inverting input, and the signal voltage 3 is inverted to the non-inverting input of the open collector output comparator 24. The reference voltage 10 is input to the input. The output of the comparator 23 and the output of the comparator 24 are connected to each other and further pulled up to 5V by the resistor 25. With this configuration, when the signal voltage 3 is higher than the reference voltage 9, the comparator 23
Output becomes 0V, and the signal voltage 3 becomes the reference voltage 9
When it is smaller, the output of the comparator 23 is open. When the signal voltage 3 is lower than the reference voltage 10, the output of the comparator 24 is 0V, and when the signal voltage 3 is higher than the reference voltage 10, the output of the comparator 24 is open.

Since the output of the comparator 23 and the output of the comparator 24 are connected to each other and further pulled up to + 5V by the resistor 25, the comparator 23
When both outputs of V and 24 are open, that is, when the signal voltage 3 is lower than the reference voltage 9 and higher than the reference voltage 10, the output 26 becomes 5V, and at least one of the comparators 23 and 24 outputs 0V. When, that is, when the signal voltage 3 is higher than the reference voltage 9 or lower than the reference voltage 10, the output 26
Becomes 0V. That is, the pixel of a color whose signal voltage 3 obtained by amplifying the voltage generated by the pixel receiving the reflected light from the original document by the amplifier circuit 2 is 1.0V to 1.5V is 5V and the other color is 5V. Pixels are separated into 0V and binarized.

Next, one embodiment of the binarization circuit 6 will be described with reference to FIG. The signal voltage 3 is input to the inverting input of the open collector output comparator 30, the reference voltage 10 is input to the non-inverting input, and the signal voltage 3 is inverted to the non-inverting input of the open collector output comparator 31. The reference voltage 11 is input to the input. Then, the output of the comparator 30 and the output of the comparator 31 are connected to each other, and the resistance 32 is 5
Has been pulled up. With this configuration, when the signal voltage 3 is higher than the reference voltage 10, the output of the comparator 30 is 0V, and when the signal voltage 3 is lower than the reference voltage 10, the output of the comparator 30 is open. When the signal voltage 3 is lower than the reference voltage 11, the output of the comparator 31 is 0V, and when the signal voltage 3 is higher than the reference voltage 11, the output of the comparator 31 is open.

Since the output of the comparator 30 and the output of the comparator 31 are connected to each other and further pulled up to + 5V by the resistor 32, the comparator 30
When both outputs of 3 and 31 are open, that is, when the signal voltage 3 is lower than the reference voltage 10 and higher than the reference voltage 11, the output 33 becomes 5V, and at least one of the comparators 30 and 31 outputs 0V. When
That is, when the signal voltage 3 is higher than the reference voltage 10 or lower than the reference voltage 11, the output 33 becomes 0V. That is, the pixel of a color whose signal voltage 3 obtained by amplifying the voltage generated by the pixel receiving the reflected light from the original document by the amplifier circuit 2 is 0.5V to 1.0V is 5V and the other color is 5V. Pixels are separated into 0V and binarized.

Next, an embodiment of the binarization circuit 7 will be described with reference to FIG. The signal voltage 3 is input to the inverting input of the open collector output comparator 27, the reference voltage 11 is input to the non-inverting input, and the output is pulled up to 5V by the resistor 28. With this configuration, when the signal voltage 3 is lower than the reference voltage 11, the output 29 of the comparator 27 is 5V, and when the signal voltage 3 is higher than the reference voltage 11, the output 29 of the comparator 27 is 0V. That is, the pixel of a color whose signal voltage 3 obtained by amplifying the voltage generated by the pixel receiving the reflected light from the original document by the amplifier circuit 2 is smaller than 0.5 V is 5 V and the pixel of another color is It is separated to 0V and binarized.

Since the image reading apparatus of this embodiment is constructed as described above, the image formed on the original is
According to the amount of light reflected from the document and received by each pixel of the CCD 1, it is separated into four colors. That is,
If the signal voltage 3 output from the amplifier circuit 2 in accordance with the amount of light received by the pixel 1a is 1.5V to 2.0V, only the output 22 of the binarization circuit 4 outputs 5V and 1.0V. ~
If it is 1.5 V, only the output 26 of the binarization circuit 5 outputs 5 V, and if it is 0.5 V to 1.0 V, only the output 33 of the binarization circuit 6 outputs 5 V, and 0 V to 0. If it is 5 V, only the output 29 of the binarization circuit 7 outputs 5 V, so that the output of the binarization circuit 4 can obtain image data in which only the portion with the largest amount of received light is separated. The output of 7 obtains image data in which only the portion having the smallest amount of received light is separated, and the output of the binarization circuits 5 and 6 obtains the image data in which the portion of an intermediate amount of received light is separated. Therefore, it is possible to separate only an image portion of a specific color from the image formed on the original, or directly obtain a plurality of image data separated for each image portion of a plurality of different colors.

An example of color separation of an image without gradation in the color reading apparatus of this embodiment will be described with reference to FIGS. 7 to 21.

The area 40 of the image shown in FIG. 7 is painted with white ink. As shown in FIG. 12, the white ink has a spectral reflectance of about 60% for all wavelengths in the visible light region.

Region 41 is painted with yellow ink.
As shown in FIG. 13, the yellow ink has a spectral reflectance 61 that reflects a wavelength of approximately 480 nm or more with respect to all wavelengths in the visible light region.

Region 42 is painted in red ink.
As shown in FIG. 14, the red ink has a spectral reflectance 62 that reflects a wavelength of approximately 580 nm or more with respect to all wavelengths in the visible light region.

Region 43 is painted in black ink.
As shown in FIG. 15, the black ink has a spectral reflectance of 63 that hardly reflects all wavelengths in the visible light region.
Have.

The region 40 is defined by the spectral distribution 6 as shown in FIG.
4 is illuminated with a light source (not shown) having a spectral sensitivity of 4 and photoelectrically converted by the CCD 1 having a spectral sensitivity of 65 as shown in FIG. 17, the CCD 1 is proportional to the integral of the spectral reflectance 60, the spectral distribution 64 and the spectral sensitivity 65. The voltage 66 is output. The voltage 66 is proportional to the area surrounded by the curve and the horizontal axis shown in FIG.

A region 41 has a spectral distribution 6 as shown in FIG.
4 is illuminated with a light source (not shown) having a spectral sensitivity of 4 and photoelectrically converted by the CCD 1 having a spectral sensitivity of 65 as shown in FIG. 17, the CCD 1 is proportional to the integral of the spectral reflectance 61, the spectral distribution 64 and the spectral sensitivity 65. The voltage 67 is output. The voltage 67 is proportional to the area surrounded by the curve and the horizontal axis shown in FIG.

The region 42 is divided into spectral distributions 6 as shown in FIG.
4 is illuminated by a light source (not shown) having a spectral sensitivity of 4 and photoelectrically converted by the CCD 1 having a spectral sensitivity of 65 as shown in FIG. 17, the CCD 1 is proportional to the integral of the spectral reflectance 62, the spectral distribution 64 and the spectral sensitivity 65. The voltage 68 is output. The voltage 68 is proportional to the area surrounded by the curve and the horizontal axis shown in FIG.

A region 43 has a spectral distribution 6 as shown in FIG.
4 is illuminated by a light source (not shown) having a spectral sensitivity of 4 and photoelectrically converted by the CCD 1 having a spectral sensitivity of 65 as shown in FIG. 17, the CCD 1 is proportional to the integral of the spectral reflectance 63, the spectral distribution 64 and the spectral sensitivity 65. The voltage 69 is output. The voltage 69 is proportional to the area surrounded by the curve and the horizontal axis shown in FIG.

The output voltage of the CCD 1 obtained as described above is amplified by the amplifying circuit 2, and when the voltage 66 is input to the amplifying circuit 2, the signal voltage 3 is 1.5V-2.
It is set to be 0V.

At this time, when the voltage 67 is input to the amplifier circuit 2, the signal voltage 3 becomes 1.0V to 1.5V.

When the voltage 68 is input to the amplifier circuit 2, the signal voltage 3 becomes 0.5V to 1.0V.

When the voltage 69 is input to the amplifier circuit 2, the signal voltage 3 becomes 0V to 0.5V.

Further, the signal voltage 3 as described above is input to the binarization circuits 4, 5, 6, and 7, and the output of the binarization circuit 4 is such that the pixel 45 included in the region 40 is 5V (the logic is 1). ), The image data 44 in which the pixels included in the other areas are 0 V (logically 0) is obtained.

At the output of the binarization circuit 5, the image data 46 in which the pixel 47 included in the area 41 is 5V (logic is 1) and the pixels included in the other areas are 0V (logic is 0) is obtained. Be done.

At the output of the binarization circuit 6, the image data 48 in which the pixel 49 included in the area 42 is 5V (logical 1) and the pixels included in the other areas are 0V (logical 0) is obtained. Be done.

At the output of the binarization circuit 7, the image data 50 in which the pixel 51 included in the area 43 is 5V (logic is 1) and the pixels included in the other areas are 0V (logic is 0) is obtained. Be done.

As described above, according to the image reading apparatus of this embodiment, the data for each area of the image drawn in the predetermined color can be easily obtained from the image drawn on the original.

Thus, for example, in an embroidery sewing machine, the image data 44, 46, 48, 50 of the areas for each color can be easily obtained by reading the color image shown in FIG. 7 with the image reading apparatus of this embodiment. By associating the image data 44, 46, 48, 50 of the respective areas with threads of any color, the embroidery data can be easily created from the handwritten image.

In the present embodiment, the amplifier circuit 2 is set so that the signal voltage 3 becomes 0 V when the CCD 1 receives no light and the signal voltage 3 becomes 2 V when the maximum amount of light is received. Accordingly, the reference voltage range is 0V and 2
The values of the signal voltage 3 and the reference voltages 9, 10, 11 are not limited to those of the present embodiment, although the values are set so as to be divided into four equal parts. The reference voltage ranges do not have to be equidistant, and may be set according to the spectral reflectance of the ink that draws an image on the document, and may be variable.

Furthermore, in this embodiment, the colors of the ink are white, yellow, red, and black, but the colors are not limited to the above four colors, and the kind and number of colors are combinations with the above reference voltage range. Therefore, it can be arbitrarily set within the range that can be separated.

The four binary images thus generated can be output in parallel as in the present embodiment or serially output through a parallel-serial converter.

[0041]

As is apparent from the above description, according to the image reading apparatus of the present invention, only an image portion of a specific color is separated from an image on a document, or image portions of a plurality of different colors are separated from each other. A plurality of separated image data can be directly obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of an electronic circuit of an image reading apparatus embodying the present invention.

FIG. 2 is a circuit diagram showing an example of a reference voltage setting circuit that constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 3 is a circuit diagram showing an example of a binarization circuit which constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 4 is a circuit diagram showing an example of a binarization circuit which constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 5 is a circuit diagram showing an example of a binarization circuit which constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 6 is a circuit diagram showing an example of a binarization circuit which constitutes an electronic circuit of the image reading apparatus of this embodiment.

FIG. 7 is an explanatory diagram showing an example of an image read by the image reading apparatus of the present embodiment.

FIG. 8 is an explanatory diagram showing an example of image data of an image read by the image reading apparatus of the present embodiment.

FIG. 9 is an explanatory diagram showing an example of image data of an image read by the image reading apparatus of the present embodiment.

FIG. 10 is an explanatory diagram showing an example of image data of an image read by the image reading apparatus of the present embodiment.

FIG. 11 is an explanatory diagram showing an example of image data of an image read by the image reading apparatus of the present embodiment.

FIG. 12 is an explanatory diagram showing characteristics of spectral reflectance of white ink with respect to visible light.

FIG. 13 is an explanatory diagram showing the characteristics of the spectral reflectance of yellow ink with respect to visible light.

FIG. 14 is an explanatory diagram showing characteristics of spectral reflectance of red ink with respect to visible light.

FIG. 15 is an explanatory diagram showing characteristics of spectral reflectance of black ink with respect to visible light.

FIG. 16 is an explanatory diagram showing a spectral distribution of a light source.

FIG. 17 is an explanatory diagram showing a spectral sensitivity characteristic of a CCD.

18 is an explanatory diagram showing the output voltage of the CCD when the region 40 is irradiated with the light source having the spectral distribution shown in FIG. 16 and photoelectrically converted by the CCD having the spectral sensitivity shown in FIG.

19 is an explanatory diagram showing the output voltage of the CCD when the region 41 is irradiated with the light source having the spectral distribution shown in FIG. 16 and photoelectrically converted by the CCD having the spectral sensitivity shown in FIG.

20 is an explanatory diagram showing the output voltage of the CCD when the region 42 is irradiated with the light source having the spectral distribution shown in FIG. 16 and photoelectrically converted by the CCD having the spectral sensitivity shown in FIG.

21 is an explanatory diagram showing the output voltage of the CCD when the region 43 is irradiated with the light source having the spectral distribution shown in FIG. 16 and photoelectrically converted by the CCD having the spectral sensitivity shown in FIG.

[Explanation of symbols]

 1 CCD 2 Amplifying circuit 3 Signal voltage 4 Binarizing circuit 5 Binarizing circuit 6 Binarizing circuit 7 Binarizing circuit 8 Reference voltage setting circuit 9 Reference voltage 10 Reference voltage 11 Reference voltage 20 Comparator 23 Comparator 24 Comparator 27 Comparator 30 comparator 31 comparator

Claims (1)

[Claims] 1. An image reading device for dividing an image on a document into a plurality of pixels to generate a digital signal for each pixel, and image forming means for forming reflected light or transmitted light from the document on a photoelectric conversion means. A photoelectric conversion means for converting the original image formed by the image forming means into a signal voltage corresponding to the amount of incident light; reference voltage setting means for setting three or more reference voltage ranges different from each other; An image reading apparatus comprising: a binarizing unit that binarizes the signal voltage depending on whether the voltage is in the reference voltage range or not.