JPH1051633A - Image input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify circuit configuration and to reduce price by eliminating a shading correction data storage section and a shading correction section from a scanner section. SOLUTION: A read section 3 reads an image from a shading correction white board 1 to provide an analog image signal. An A/D converter 4 converts an analog image signal into digital image data to obtain shading correction data W(i). A data transfer section 5 transfers the data W(i) to a host computer 9. The host computer 9 stores the data W(i) to the shading correction data storage section 7. The A/D converter 4 converts an image signal from an original 2a into the digital image data IMG(i, j). The data transfer section 5 transfers the data to the host computer 9. The shading correction section 8 uses the data W(i) stored in a correction data storage section 7 so as to conduct the shading correction for the digital image data IMG(i, j).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image input device having a scanner unit and a host computer.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of a conventional image input device. In FIG. 6, 21 is a white plate used for shading correction, 22 is a document reading table on which a document to be read is placed, 23 is a reading unit including a light source, a lens, a CCD sensor, etc., and 24 is a converter for converting an analog signal into a digital signal. A / D converter, 25 is a shading correction data storage unit, 26 is a shading correction unit, 27 is an image processing unit that performs processes such as resolution conversion, color correction, gradation correction, and image conversion, and 28 is image data transfer Data transfer unit, 2
Reference numeral 9 denotes a scanner unit including components 21 to 28. Reference numeral 30 denotes an image data storage unit for storing input image data, and reference numeral 31 denotes a host computer having an image data storage unit.

An image reading operation of the image input apparatus having the above-described configuration will be described. First, the reading unit 23 reads an image from the shading correction white plate 21 and outputs an analog image signal, and the A / D converter 24 converts the analog image signal into digital image data.
The digital image data is stored in the shading correction data storage unit 25. Next, the reading unit 23 reads an image line by line from the original on the original reading table 22 and outputs an analog image signal, and the A / D converter 24 converts the analog image signal into digital image data IMG (i, j). , And the digital image data is input to the shading correction unit 26, and the shading correction is performed using the correction data W (i) stored in the shading correction data storage unit 25. Shading correction refers to correcting variations in the brightness of the light source, variations in the sensitivity of the CCD sensor, and the like.
Let G2 (i, j) be the digital image data IMG2
(I, j) is represented by (Equation 1).

[0004]

(Equation 1)

In equation (1), j indicates the j-th line in the sub-scanning direction, i indicates the i-th pixel in the main scanning direction, and n
Is the number of pixel configuration bits per color of the output image data of the A / D converter 24.

Image data IMG after shading correction
2 (i, j) is sent to the image processing unit 27, where it is subjected to processing such as color correction, resolution correction, gradation correction, etc.
Each line is transferred to the host computer 31 and stored in the image data storage unit 30. Then, the host computer 31 displays the image data or outputs the image data to an external device.

[0007]

However, in the above-mentioned conventional image input apparatus, the shading correction data storage section 25 which is a memory buffer for storing shading correction data and the shading correction section 26 which is a correction circuit.
And the problem that it is difficult to reduce the cost due to the complicated circuit configuration.

In this image input device, there is a demand for eliminating the shading correction data storage section and the shading correction section from the scanner section, thereby simplifying the circuit configuration and achieving low cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image input apparatus capable of simplifying a circuit configuration and reducing cost by eliminating a shading correction data storage section and a shading correction section from a scanner section.

[0010]

An image input apparatus according to the present invention is an image input apparatus having a scanner section and a host computer, wherein the scanner section uses a white plate used for shading correction. A reading unit for reading an image from a white plate and a document to output an analog image signal, an A / D converter for converting the analog image signal into digital image data, and digital image data output from the A / D converter A shading correction data storage unit in which a host computer inputs and stores digital image data of a white plate, and a shading which inputs digital image data of a document and performs shading correction. And a correction unit.

As a result, an image input device can be obtained in which the shading correction data storage section and the shading correction section are eliminated from the scanner section, thereby simplifying the circuit configuration and reducing the cost.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is an image input apparatus having a scanner unit and a host computer, wherein the scanner unit includes a white plate used for shading correction, a white plate, A reading unit that reads an image from a document and outputs an analog image signal, an A / D converter that converts the analog image signal into digital image data, and transfers digital image data output from the A / D converter to the outside A data transfer unit, wherein the host computer has a shading correction data storage unit for inputting and storing digital image data of a white plate, and a shading correction unit for inputting digital image data of a document and performing shading correction The effect is that shading correction is performed by the host computer. That.

According to a second aspect of the present invention, in the first aspect, the white plate is disposed in the main scanning direction of the image reading, and the shading correction unit performs the main scanning shading correction. There is an effect that the shading correction is performed linearly.

According to a third aspect of the present invention, in the first aspect, the white plate is provided in the main scanning direction and the sub-scanning direction of the image reading, and the shading correction unit is provided in the main scanning direction and the sub-scanning direction. The two-dimensional shading correction is performed, and has an effect that the shading correction is performed two-dimensionally.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the white plate is provided over the entire reading range of the reading stand cover, and the shading correction unit performs surface shading correction. This has the effect that the shading correction is performed two-dimensionally.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a block diagram showing an image input apparatus according to Embodiment 1 of the present invention. In FIG. 1, a white plate 1 for shading correction, a document reading table 2,
The reading unit 3, the A / D converter 4, and the data transfer unit 5 are a white plate 21 for shading correction, a document reading table 22,
This corresponds to the reading unit 23, the A / D converter 24, and the data transfer unit 28, and a description thereof will be omitted. Reference numeral 6 denotes a scanner unit including components 1 to 5, reference numeral 7 denotes a shading correction data storage unit that stores read image data of the shading correction white plate 1 when the image data is transferred from the scanner unit 6, and reference numeral 8 denotes a scanner. A shading correction unit 9 for performing shading correction on the read image data of the document output from the unit 6, and a host computer 9 having components 7 and 8.

FIG. 3 is an arrangement diagram showing an arrangement of a shading correction white plate. In FIG. 3, the shading correction white plate 1, the document reading table 2, and the reading unit 3 are the same as those in FIG. 2
a is an original placed on the original reading table 2. As shown in FIG. 3, the shading correction white plate 1 is disposed in the main scanning direction indicated by the arrow AR1 in front of the document reading table 2, and the reading unit 3 is in the sub-scanning direction (a direction perpendicular to the arrow AR1). To read the original on the white plate for shading correction 1 and the original reading table 2.

The operation of the image input device configured as described above will be described. First, the reading unit 3 reads an image from the shading correction white plate 1 and outputs an analog image signal. The A / D converter 4 converts the analog image signal from the shading correction white plate 1 into digital image data, and outputs the shading correction data W
(I) is obtained. The data transfer unit 5 transfers the shading correction data W (i) to the host computer 9. The host computer 9 stores the shading correction data W
(I) is stored in the shading correction data storage unit 7. Next, the reading unit 3 reads an image from the document 2a on the document reading table 2 line by line and outputs an analog image signal. The A / D converter 4 converts an analog image signal from the original 2a into digital image data IMG (i, j). The data transfer unit 5 is a digital image data IMG
(I, j) is transferred to the host computer 9. In the host computer 9, the shading correction unit 8
Performs shading correction on the digital image data IMG (i, j) using the shading correction data W (i) stored in the shading correction data storage unit 7. If the digital image data after shading correction is IMG2 (i, j), the digital image data IM
G2 (i, j) is represented by the above (Equation 1).

Here, IMG (i, j) is the i of the j line.
IMG2 (i, j) is the digital image data after shading correction of the i-th pixel of the j-th line, W (i)
Is the i-th shading correction data stored in the shading correction data storage unit 7, and n is the A / D converter 4.
Is the number of pixel configuration bits per color of the output image data. In this manner, the image data IMG subjected to one-dimensional shading correction processing on the host computer 9 side
2 can be obtained.

As described above, according to the present embodiment, the shading correction data storage unit 7 and the shading correction unit 8 are provided in the host computer 9, so that
The shading correction data storage unit and the shading correction unit can be eliminated from the scanner unit 6.

(Embodiment 2) FIG. 2 is a block diagram showing an image input apparatus according to Embodiment 2 of the present invention.
In FIG. 2, the document reading table 2, reading unit 3, A / D converter 4, and data transfer unit 5 are the same as those in FIG. 1a is a first white plate for shading correction, and 1b is a second white plate for shading correction. In FIG. 2, reference numeral 7a denotes a first shading correction data storage unit that stores read image data U of the first white plate 1a, and 7b denotes a second shading correction data storage unit that stores read image data V of the second white plate 1b. The shading correction data storage unit 8 is configured to store the shading correction data stored in the first shading correction data storage unit 7a and the second shading correction data storage unit 7b for the read image data of the document output from the scanner unit 6. A shading correction unit that performs shading correction using data.

FIG. 4 is an arrangement diagram showing the arrangement of the first and second white plates 1a and 1b. In FIG. 4, the document reading table 2, the document 2a, and the reading unit 3 are the same as those in FIG.
The same reference numerals are given and the description is omitted. As shown in FIG.
The first white plate 1a is an arrow AR1 in front of the document reading table 2.
And the second white plate 1b
Are arranged in the sub-scanning direction (the direction perpendicular to the arrow AR1).

The operation of the image input device configured as described above will be described. First, the reading unit 3 reads an image from the first white plate 1a and outputs an analog image signal. The A / D converter 4 converts an analog image signal from the first white plate 1a into digital image data to obtain first shading correction data U (i). The data transfer unit 5 transfers the first shading correction data U (i) to the host computer 9. Host computer 9
Stores the first shading correction data U (i) in the first shading correction data storage unit 7a. Next, the reading section 3 reads an image from the second white plate 1b and outputs an analog image signal. The A / D converter 4 is the second
The analog image signal from the white plate 1b is converted into digital image data, and the second shading correction data V
(J) is obtained. The data transfer unit 5 transfers the second shading correction data V (j) to the host computer 9. The host computer 9 stores the second shading correction data V (j) in the second shading correction data storage 7b.

Next, the reading section 3 reads an image from the document 2a on the document reading table 2 line by line and outputs an analog image signal. The A / D converter 4 converts the analog image signal from the original 2a into digital image data IMG (i,
j). The data transfer unit 5 transfers the digital image data IMG (i, j) to the host computer 9.
In the host computer 9, the shading correction unit 8 stores the first shading correction data U (i) stored in the first shading correction data storage unit 7a.
Then, shading correction is performed on the digital image data IMG (i, j) using the second shading correction data V (j) stored in the second shading correction data storage unit 7b. Assuming that the digital image data after shading correction is IMG2 (i, j), the digital image data IMG2 (i, j) is represented by (Equation 2).

[0025]

(Equation 2)

Here, IMG (i, j) is the i-th of the j-th line.
IMG2 (i, j) is the digital image data after shading correction of the i-th pixel of the j-th line, W (i,
j) is shading correction data for the i-th pixel on the j-th line, and n is the number of pixel configuration bits per color of the output image data of the A / D converter 4. The shading correction data W (i, j) can be calculated from the first shading correction data U (i) and the second shading correction data V (j). This is shown in (Equation 3).

[0027]

(Equation 3)

In this way, the host computer 9 can obtain the image data IMG2 that has been subjected to the two-dimensional shading correction processing.

As described above, according to the present embodiment, the first and second shading correction data storage units 7a and 7b
And a shading correction unit 8 to a host computer 9
The shading correction data storage unit and the shading correction unit can be eliminated from the scanner unit 6. Further, two-dimensional shading correction processing can be performed by the two shading correction data storage units 7a and 7b.

(Embodiment 3) An image input apparatus according to Embodiment 3 of the present invention has the same configuration as that of FIG. 1, and a description thereof will be omitted.

FIG. 5 is an arrangement diagram showing an arrangement of a shading correction white plate of the image input device according to the third embodiment of the present invention. In FIG. 5, an original reading table 2, an original 2
a, the reading unit 3 is the same as that in FIG. 3, so the same reference numerals are given and the description is omitted. Reference numeral 10 denotes a shading correction white plate, and reference numeral 11 denotes a reading stand cover on which the shading correction white plate 10 is disposed.

The operation of the thus configured image input apparatus will be described. First, in a state where the original 2a is not placed on the original reading table 2, the reading unit 3 reads an image from the white plate 10 for shading correction and outputs an analog image signal. The A / D converter 4 converts an analog image signal from the shading correction white plate 10 into digital image data, and outputs shading correction data W (i, j).
Get. The data transfer unit 5 transfers the shading correction data W (i, j) to the host computer 9. The host computer 9 stores the shading correction data W
(I, j) is stored in the shading correction data storage 7.

Next, the original 2 a is placed on the original reading table 2. The reading unit 3 reads an image from the document 2a on the document reading table 2 line by line and outputs an analog image signal. The A / D converter 4 converts an analog image signal from the original 2a into digital image data IMG (i, j). The data transfer unit 5 transmits the digital image data IMG (i,
j) is transferred to the host computer 9. In the host computer 9, the shading correction unit 8 performs shading correction using the shading correction data W (i, j) stored in the shading correction data storage unit 7. Assuming that the digital image data after shading correction is IMG2 (i, j), the digital image data IMG2 (i, j) is represented by the above (Equation 2).

Here, IMG (i, j) is the i-th of the j-th line.
IMG2 (i, j) is the digital image data after shading correction of the i-th pixel of the j-th line, W (i,
j) is shading correction data of the i-th pixel on the j-th line. Thus, the host computer 9
The image data IMG2 that has been subjected to surface shading correction processing on the side can be obtained.

As described above, according to the present embodiment, the shading correction data storage unit 7 and the shading correction unit 8 are provided in the host computer 9, so that
The shading correction data storage unit and the shading correction unit can be eliminated from the scanner unit 6. Also,
Shading correction white plate 1 on reading stand cover 11
Surface shading correction processing can be performed using the shading correction data W (i, j) based on 0.

[0036]

As described above, according to the image input apparatus of the present invention, since the shading correction data storage section and the shading correction section are provided in the host computer, the shading correction data storage section and the shading correction section can be combined with the scanner section. This has the advantageous effect that the circuit configuration in the scanner section can be simplified and the cost can be reduced.

Further, by providing the white plate in the main scanning direction of image reading and performing main scanning shading correction by the shading correction unit, there is an advantageous effect that one-dimensional shading correction can be performed.

Further, two white plates are arranged in the main scanning direction and the sub-scanning direction of image reading, and the shading correction unit performs two-dimensional shading correction in the main scanning direction and the sub-scanning direction, thereby providing two-dimensional shading. Correction can be performed, and the advantageous effect that shading correction can be performed accurately can be obtained.

Further, the white plate is disposed over the entire reading range of the reading stand cover, and the shading correction unit performs the surface shading correction, so that the surface shading correction can be performed, and the shading correction can be performed more accurately. The advantageous effect that it can be performed is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an image input device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an image input device according to a second embodiment of the present invention.

FIG. 3 is an arrangement diagram showing an arrangement of a white plate for shading correction.

FIG. 4 is an arrangement diagram showing an arrangement of first and second white plates;

FIG. 5 is an arrangement diagram showing an arrangement of a shading correction white plate of the image input device according to the third embodiment of the present invention;

FIG. 6 is a block diagram of a conventional image input device.

[Explanation of symbols]

 1, 10 White plate for shading correction 1a First white plate 1b Second white plate 2 Document reading table 2a Document 3 Reading unit 4 A / D converter 5 Data transfer unit 6 Scanner unit 7 Shading correction data storage unit 7a No. 1 shading correction data storage unit 7b Second shading correction data storage unit 8 Shading correction unit 9 Host computer 11 Reading board cover

Claims (4)

[Claims] 1. An image input apparatus having a scanner unit and a host computer, wherein the scanner unit reads an image from a white plate used for shading correction, an image from the white plate and a document, and outputs an analog image signal. A reading unit, an A / D converter that converts the analog image signal into digital image data, and a data transfer unit that externally transfers the digital image data output from the A / D converter, An image characterized in that a host computer has a shading correction data storage unit for inputting and storing digital image data of the white plate, and a shading correction unit for inputting digital image data of the original and performing shading correction. Input device. 2. The image input device according to claim 1, wherein the white plate is disposed in a main scanning direction of image reading, and a shading correction unit performs main scanning shading correction. 3. The image forming apparatus according to claim 1, wherein the white plate is disposed in a main scanning direction and a sub-scanning direction of image reading, and a shading correction unit performs two-dimensional shading correction in the main scanning direction and the sub-scanning direction. An image input device according to claim 1. 4. The image input device according to claim 1, wherein the white plate is provided over the entire reading range of the reading stand cover, and a shading correction unit performs surface shading correction.