JPH08139876A - Equipment for attaining high image quality for transmission image and reception image - Google Patents

Abstract

PURPOSE: To reduce a memory amount by using a storage means of one set of image data in common for image processing at reading and image processing at reception so as to use only one memory provided to both reading and receiving states. CONSTITUTION: A light from a light source 60 is emitted onto an original 70 and a sensor 80 sensing its reflected light reads a read object, a read image processing section 10 applies image processing for high image quality to the image data converted into a digital signal by an A/D converter. In this case, a selector 30 selects the read image processing section 10 and the read image processing section 10 uses a line memory 40. Then the signal is sent to a communication line via a modem 100. In the case of reception, the coded data from the communication line are decoded via the modem 100 at a decoding section 110, a recording image processing section 20 applies high image quality processing such as interpolation processing and the processed data are transferred to a print head 120, by which the data are printed out (130). In the case of reception, the selector 30 selects the recording image processing section 20 and the recording image processing section 20 uses the line memory 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image quality improving apparatus for performing image processing for transmitting and receiving image data, and more particularly to image processing for facsimile.

[0002]

2. Description of the Related Art In a conventional facsimile, high quality image processing is performed on read image data, and for example, image processing for correcting distortion and blurring caused in a reading system is performed to improve output image quality. There is. However, since image processing for correcting blurring is performed by referring to peripheral pixels,
A memory for storing the density information of pixels in the sub-scanning direction for several lines is required. Further, there is a method for improving the image quality by performing smoothing processing (interpolation processing) on the received image data as well, but in this case as well, since peripheral pixels are referenced, a memory for several lines is required. For this reason, in order to achieve high image quality in transmission (copying) and reception, a memory is provided for each of image processing for reading and image processing for receiving.

[0003]

However, in order to improve the image quality, the amount of memory used for image processing for reading (transmission, copy) and the amount of memory used for image processing during reception are required. There is a problem that the amount of memory increases and the cost increases.

It is an object of the present invention to provide an image quality improving apparatus which prevents an increase in line memory in an apparatus for improving the image quality of a transmitted image and a received image.

[0005]

SUMMARY OF THE INVENTION The above object is to provide one image data storage means in an apparatus for image-processing and transmitting read image data and image-processing the received image data. This is achieved by sharing and using the image processing means at the time of transmission and the image processing means at the time of reception. Specifically, a memory having the larger memory amount of the memory amount required for the read image processing and the memory amount required for the image processing at the time of reception is provided.
Switching means 3 for selecting which of the read image processing 1 and the recording image processing uses the memory 2 as described above.
Can be realized by providing.

[0006]

By using one image data storage means for both image processing (transmission, copy) at the time of reading and image processing at the time of reception, the memory conventionally provided for each can be made one. Therefore, the amount of memory can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 2 shows an example of a schematic configuration of a facsimile apparatus of the present invention.

As shown in FIG. 2, the flow of the image signal of the facsimile apparatus in the present invention irradiates the original 70 with the light from the light source 60 and reads the object to be read by the sensor 80 which detects the reflected light. In the read image processing unit 10, A / D
For the image data converted into a digital signal by the converter,
Image processing is performed to improve image quality. At this time, the selector 3
0 selects the read image processing unit 10, and the line memory 40
Is used by the read image processing unit 10. After that, the image data that has been binarized by the read image processing unit 10 is information amount compression encoded by the encoding unit 90, and is transmitted to the communication line via the modem 100. At the time of reception, the coded data is decoded by the decoding unit 110 via the communication line through the modem 100, the recording image processing unit 20 performs image quality enhancement processing such as interpolation processing, and transfers it to the print head 120 for printing. Output 130. At the time of reception, the selector 30 selects the recording image processing unit 20, and the line memory 4
0 is used by the recording unit image processing 20. FIG. 3 shows a configuration example of the read image processing unit.

Image data from the sensor is 8-bit A / D
The converter 11 digitizes the data, and the reading distortion (shading distortion) due to the light source of the reading unit and the sensor sensitivity unevenness is corrected by the shading distortion correction unit 12, and the edge emphasis unit 13 leaks light and thin lines due to defocusing and blurring. To correct
The error diffusion binarization unit 14 performs binarization that can express light and shade in a pseudo manner. In addition, the shading distortion correction unit 12 needs to store the shading distortion data, the edge emphasis unit 13 needs to store the reference image data, and the error diffusion binarization unit 14 needs to store the error data in the line memory 40 through the selector 30. Next, a specific example of the shading distortion correction unit is shown in FIG.
Shown in

In order to correct the shading distortion of the reading unit, it is necessary to store the distortion characteristic of the reading unit in advance.
As a specific process of storing, for example, a white original is read before the product is shipped, its sensor output is digitized by the 8-bit A / D converter 11, and stored in the line memory 40 via the selector 30. In the transmission and copy reading processing, the shading distortion correction processing can be realized by reading the shading distortion data from the line memory 40 and dividing the shading distortion data with respect to the image data (8 bits / pixel) obtained by reading the document. .

Next, a configuration example of the edge emphasizing section is shown in FIG.
Image data (P-2, P-
, P0, ...) and the image data of the previous line (L-2, L-
, L0, ...) is subjected to a convolution calculation with a coefficient matrix of 5 pixels in the main scanning and 2 pixels in the sub-scanning, and the calculation result is image data at the P0 pixel position (pixel to be processed). In addition, the image data of the current line input from the sensor is written into the line memory 40 through the selector 30.

Next, FIG. 6 shows a concrete example of the error diffusion binarization unit. The error diffusion process is a binarization process in which a binarization error that occurs when binarizing image data is reduced to peripheral pixels and a grayscale expression in a wide area can be reproduced in a pseudo manner. In the error data of the previous line stored in the line memory 40, the weighting coefficient B148,
Add 149 and 147 multiplied by C146 and 145 multiplied by the weighting coefficient A144 to the binarization error of the previous pixel 141
Then, the binarization unit 142 executes the binarization process. This time,
The generated binarization error is obtained by subtracting the data before binarization from the data after binarization by the binarization unit 142, and the error of the current line is processed through the selector 30 for processing the next line. It is stored in the memory 40.

Next, a concrete example of the recorded image processing section is shown in FIG. At the time of reception, the resolution of the binary image data decoded by the decoding unit 110 is normal (sub-scan 3.85 lines / mm).
In this case, interpolation processing is performed by the interpolation processing section 21 and pseudo fine (sub scanning 7.7 lines / mm) is converted and printing is performed. Further, in the interpolation processing unit 21, in order to improve the image quality of the central pixel based on the information of a total of 15 pixels of the main scanning 5 pixels × the sub scanning 3 pixels of the received binary image data, the binary image for 2 lines from the line memory. Enter the data. The binary image data is sequentially stored in the line memory line by line.

For example, as shown in FIG. 8, binary image data having a resolution of 3.85 lines / mm in the sub-scanning is converted into 7.7 lines / mm in the sub-scanning, and one pixel is divided into the first half and the second half. Two
When printing is divided into times, it becomes as shown in FIG. At this time, in order to prevent the step difference of one pixel from being enlarged and difficult to see, the first half is white and the second half is inverted to black so that the jagged steps caused by diagonal lines are smooth. Become a line.

FIG. 9 shows a concrete example of the interpolation processing section. A pattern matching circuit is provided for the 3-line data of the binarized data from the decoding unit 110 and the binarized data from the line memory.
Enter in 211. Here, it is detected whether or not it matches a specific pattern as shown in FIG. 10, and when they match,
The latter half pixels are printed by converting the signals of the binarized data of the first half through the inverting circuit 212 by controlling the selector 213. If they do not match, the second half pixel is set to the selector 2
13 is controlled to print the same data as the first half print data. Further, the specific pattern in FIG. 10 is targeted vertically.

Regarding the switching of the selector 30, the read image processing unit 10 uses the line memory 40 at the time of transmission and copying, and the recording image processing unit 2 at the time of reception.
0 switches to use the line memory 40. Further, transmission, copy and reception may not be operated at the same time. This switching signal is output from the MPU 50. When the read image processing unit 10 uses the line memory 40, multivalued image data is stored, and when the recorded image processing unit 20 uses the line memory 40, binary image data is stored. By sharing and using the image processing for improving the image quality of the reading unit and the image processing for improving the image quality of the recording unit in one line memory, the memory amount can be reduced and the image quality can be improved. it can.

[0017]

According to the present invention, it is possible to realize the high image quality processing at the time of transmission and copying and the high image quality processing at the time of reception with a small memory amount, and it is possible to obtain a good image quality at low cost.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of the present invention.

FIG. 2 is a diagram showing a schematic configuration example of a facsimile apparatus according to the present invention.

FIG. 3 is a diagram illustrating a configuration example of a read image processing unit.

FIG. 4 is a diagram showing a specific example of a shading distortion correction unit.

FIG. 5 is a diagram showing a specific example of an edge enhancement unit.

FIG. 6 is a diagram showing a specific example of an error diffusion binarization unit.

FIG. 7 is a diagram showing a configuration example of a recorded image processing unit.

FIG. 8 is a diagram showing an example of an effect of interpolation processing.

FIG. 9 is a diagram showing a specific example of an interpolation processing unit.

FIG. 10 is a diagram showing an example of a specific pattern of an interpolation processing unit.

[Explanation of symbols]

1 ... Transmission, copy image processing, 2 ... Reception image processing, 3 ... Switching means, 4 ... Line memory, 10 ... Read image processing unit, 11 ... 8bit A / D, 12 ... Shading distortion correction unit, 13 ... Edge enhancement unit, 14 ... Error diffusion binarization unit, 2
0 ... recorded image processing unit, 21 ... interpolation processing unit, 30, 213
... selector, 40 ... line memory, 50 ... MPU, 60
... light source, 70 ... original, 80 ... sensor, 90 ... encoding unit,
100 ... Modem, 110 ... Decoding section, 120 ... Print head, 121 ... Divider, 130 ... Print output, 131 ... Convolution operation, 141 ... Adder, 142 ... Binarization section, 143 ... Subtractor, 144 , 146, 148 ... Weighting coefficient, 145, 147, 149 ... Multiplier, 211 ... Pattern matching circuit, 212 ... Inversion circuit.

Claims (5)

[Claims] 1. An apparatus for image-processing and transmitting read image data and image-processing the received image data and recording the image data, wherein a storage means for storing one image data and an image processing means at the time of transmission are provided. An image quality improving apparatus characterized by being used in common with image processing means at the time of reception. 2. An apparatus for image-processing read-image data and transmitting the image data and image-processing the received image data for recording, and at least image-processing means at the time of transmission and image-processing means at the time of reception. , Means for storing image data (line memory)
And a switching means for switching the means for storing the image data so that either the image processing means at the time of transmission or the image processing means at the time of reception can be used. 3. The image quality improving apparatus according to claim 1 or 2, wherein the image processing at the time of transmission has at least edge enhancement processing means, and the image processing at the time of reception has at least interpolation processing means. Image quality improvement device. 4. The image quality improving apparatus according to claim 1, wherein multivalued data is stored when a memory is used for image processing during transmission, and multivalued data is stored when the memory is used for image processing during reception. An image quality improving device characterized by storing binary data. 5. The image quality improving apparatus according to claim 1 or 2, wherein transmission and reception are not operated at the same time.