JPH0622156A - Color picture transmitter - Google Patents

Abstract

PURPOSE:To provide a color facsimile equipment by which mutual transmission of a picture is attained with a monochromatic facsimile equipment by providing a binarizing processing unit in the transmitter so as to convert a color picture stored in a picture memory into a monochromatic picture. CONSTITUTION:When the reception of color picture data is finished at the time of reception, a system controller 1 uses an operation/section 2 and a CRT I/F section 9 to display the end of reception. Then a binarizing processing section 11 is started to expand compressed data and expands the data into a picture memory section 6 in a designated color. The controller 1 displays the result on a CRT or allows a plotter section 7 to print out the result for each prescribed processing unit of the processing section 11. Thus, inter-communication between a color facsimile equipment and a monochromatic facsimile equipment is economically attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image transmission apparatus, and more particularly to a color image transmission apparatus which can communicate with conventional monochrome facsimile machines and G3 facsimile machines.

[0002]

2. Description of the Related Art Recently, a full-color facsimile (color image transmission device) capable of transmitting a full-color image has appeared. Further, the following has been proposed so far as a full-color binarization processing means. That is, JP-A-63-283954 and JP-A-01-122439.
Japanese Patent Laid-Open No. 01-124064 and Japanese Patent Laid-Open No. 64
No. 26280, No. 02-166969 and No. 02-274178.

[0003]

However, the conventional color facsimiles can communicate only between color facsimiles, and image transmission between the color facsimiles and the most popular monochrome facsimiles is impossible.
Further, up to now, the binarization processing means for reproducing a full-color original document cannot realize the fine binarization processing.

Therefore, a first object of the present invention is to provide a color facsimile capable of mutual image transmission with the conventional monochrome facsimile. A second object of the present invention is to provide a binarization processing means capable of finely binarizing a full-color original.

[0005]

According to a first aspect of the present invention, in a color image transmission apparatus including an image memory device for storing a read color image or a received color image, the color image stored in the image memory device is A binary processing device for converting into a monochrome image is provided. According to a second aspect of the present invention, in an image transmission apparatus having an image memory device for storing a read color image or a received color image, a control device for outputting a specific one color when a monochrome image is received is provided. Configured. According to the third aspect of the invention, the color image is read in RGB, and RGB is read.
Each element of the signal is combined by or or and, or arithmetically averaged and binarized by a predetermined threshold value.

According to the fourth aspect of the invention, the color image is R
The threshold value is set for each element of the RGB signal by reading with the GB signal, and the binarized value corresponding to the RGB signal after binarizing the RGB signal with each threshold value is or or and
Are combined with each other or added to perform binarization conversion at a predetermined threshold value. In the invention according to claim 5, the color image is read by the RGB signal, and the lightness corresponding to the value of each element of the RGB signal is combined with or or and, or arithmetic averaged, and 2 is set at a predetermined threshold value. Changed to digitize. In the invention according to claim 6, a color image is read by an RGB signal, a threshold value is set for each lightness corresponding to a value of each element of the RGB signal, and binarization is performed after binarization with each threshold value. The binarized values are combined by or or and, or they are added and binarized by a predetermined threshold value.

[0007]

In the color image transmission device according to the first aspect, the binarization processing unit binarizes the received color image (RGB signal image data) to convert it into a monochrome image. In the color image transmission device according to the second aspect, when a monochrome image is received, the compressed and accumulated encoded data is expanded by the binarization processing unit. Decompressed data,
It is developed in the image memory with the specified color. One specific color is output according to this designated color. In the binarization processing method according to claim 3, a color image is read by RGB signals, and RG is read.
Combine each element of B signal with or or and, or
The arithmetic mean is calculated and binarized by a predetermined threshold value.

In the binarization processing method according to the fourth aspect, a color image is read by RGB signals, a threshold value is set for each element of the RGB signal, and the RGB signal is set to 2 by each threshold value.
Binarized values corresponding to the RGB signals after binarization are combined by or or and, or added to be binarized and converted by a predetermined threshold value. In the binarization processing method according to claim 5, a color image is read by an RGB signal, and the lightness corresponding to each value of each element of the RGB signal is combined by or or and, or arithmetic average is performed to determine a predetermined value. Binarize the threshold value. In the binarization processing method according to claim 6, a color image is read by an RGB signal, a threshold value is set for each lightness corresponding to a value of each element of the RGB signal, and binarization is performed by each threshold value. The subsequent binarized values are combined by or or and, or they are added and binarized by a predetermined threshold value.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the color image transmitting apparatus of the present invention will be described in detail below with reference to FIGS. FIG. 1 shows a block configuration of this embodiment. First, the function of each block will be described. The system controller unit 1 manages activation of each unit and state management, and is configured by a CPU, a memory, a BUSI / F, and the like. It also controls the operation unit 2 and the secondary storage device 3 described below and transfers data to and from these devices. The operation unit 2 is FA
It consists of various keys for starting X (facsimile), inputting a telephone number, and other FAX operations, a liquid crystal panel capable of displaying various operation procedures and machine status, and other display devices. To be done.

The scanner unit 4 is a device for inputting image data from a document, and is constituted by a well-known technique such as a light source, a photoelectric conversion element, an A / D converter, and a BUSI / F. Use filters to get color image data,
Three RGB signals are read simultaneously. RGB obtained
The signal data is sent to the memory unit via the BUSI / F.

The codec section 5 transfers image data to and from the image memory section 6 and compresses and expands the image data according to the JPEG system. For a detailed explanation of the JPEG method, refer to "PCSJ90 Image Coding Lecture Preliminary Collection"
And "International Standardization Trends for Color Still Image Coding". The data compressed by the codec section 5 is
It is transmitted / received to / from the ISDN unit through the BUSI / F. As shown in FIG. 2, the codec section 5 includes a CPU 12, a memory 13, a DSP 14, a DMA 15, a FIFO 16 and a B.
It is composed of USI / F17 and the like. The schematic operation of the codec section 5 is as shown in FIG. As for the operation of each unit, first, the DMA 15 transfers the RGB signal image data to and from the image memory unit, and the color conversion / DCT calculation / quantization is performed as follows.
The DSP (digital single processor: performs calculations such as addition, subtraction, multiplication, and division at high speed) 14 performs C / Huffman coding, control of the entire sequence, and control of the DMA 15 and DSP 14.
PU12 does. FIFO (First In First Out)
The memory 13 is a means for operating the DSP 14 without delay when transmitting / receiving image data by the DMA 15.
The CPU 12 is means for temporarily storing programs and code data.

The DCT (Discrete Cosine Transform)
) Operation is a discrete cosine transform. This is one of the orthogonal transformations, but it is applied to the still image coding method, and is currently being standardized by ISO and CCITT. Here, the two-dimensional DCT will be described. The pixels forming the image are divided into an 8 × 8 matrix of 8 pixels in the vertical direction and 8 pixels in the horizontal direction, and the value of each pixel is f (i, j) (where i = 0 to 7, j = 0 to 7). In other words, the DCT mapping F (u, v) is obtained by the following equation (1). u = 0 to 7, v = 0 to 7: F (u, v) = [4 · C (u) · C (v) / (N · N)] · ΣΣf (i, j) · cos [(2・ I + 1) ・ u ・ π / (2 ・ N)] ・ cos [(2 ・ j + 1) ・ v ・ π / (2 ・ N)] ...... (1)

Here, the addition range of both Σ is i = 0 to (N-
1) and j = 0 to (N-1), u = 0 to 7, v
= 0 to 7. This is called a DCT coefficient and is given by an 8 × 8 coefficient matrix. Where C (W) is C (W) = 1 / √
2 (when W = 0) or C (W) = 1 (W = 1, 2, ...,
N −1). Further, the inverse DCT is expressed by the following equation (2)
Required by. F (i, j) = ΣΣC (u) · C (v) · F (u, v) · cos [(2 · i + 1) · u · π / (2 · N)] · cos [(2 · j + 1) ) · V · π / (2 · N)] (2) Here, the addition range of both Σ is u = 0 to (N−1) and v
= 0 to (N-1).

The 8 × 8 coefficient matrix F (u, v) is
As u and v increase, the spatial frequency included in the image corresponds to the conversion coefficient of a higher frequency component, and F (0,
0) corresponds to the coefficient of the DC component. That is, in the top row, from the top of the coefficient of the horizontal component of the spatial frequency contained in the image, from the lowest frequency component to the top, in the leftmost column, similarly, the coefficient of the frequency of the vertical component The lowest component corresponds to the left component, and the upper left component corresponds to the DC component coefficient of the image. The diagonal portions correspond to the coefficients of the frequency in which the horizontal and vertical lines are superimposed. The image memory unit 6 is a frame buffer configured by a BUS I / F and a memory and for storing uncompressed input / output image data. The image memory unit 6 is used to store the image data read by the scanner unit 4 or the image data output to the printer unit.

The ISDN I / F unit 8 comprises an I / F circuit for the ISDN line, a CPU, a memory, and a BUSI / F. And in this ISDNI / F unit 8,
It controls the protocol for communication and sends and receives compressed encoded data. The communication protocol uses an expanded function of G4 class 1 and adds color coded expression capability.

The CRT I / F unit 9 comprises a display memory for displaying on the CRT 10, a DMA, a timing controller for display, a D / A converter, and a BUSI / F. Data is fetched from the image memory unit 6 into the display memory via the BUSI / F by the DMA, converted into an analog signal by the D / A converter, and displayed on the CRT 10.

The plotter unit 7 includes a DMA, BUSI / F,
The color ink ribbon, the thermal head, the paper transport mechanism, and other known techniques are used. Image data is fetched from the image memory unit 6 by DMA, and the color of the color ink ribbon is printed on the paper by the heat of the thermal head according to the color information. The binarization processing unit 11 transfers image data to and from the image memory unit 6, and performs binarization processing and compression of color image data, decompression of compressed data, and color imaging. As shown in FIG. 4, the binarization processing unit 11 includes a CPU 21, a memory 22, a DMA, a binarization circuit, a BUSI / F 23, and the like. The operation of the binarization processing unit 11 is as shown in FIG. That is, DMA
Transfers the RGB signal image data to and from the image memory unit 6, performs binarization by the binarization circuit, and performs the Huffman encoding / decoding, the entire sequence control, and the DMA and the binarization circuit control by the CPU 21. Do.

Next, an outline of the operation of the embodiment thus constructed will be described with reference to FIG. Here, the outline of the operation will be described by dividing it into “when transmitting” and “when receiving”. The system controller 1 controls the entire flow. At the beginning of reception, it is in a standby state (step 1), and when it is received (step 2), the function of the partner machine is confirmed by the protocol CSS / RSSP, and if "there is color transmission capability", Is session protocol CDCL / RD
Check the color transmission function by CLP.

After that, the receiving operation is started, and while the receiving operation is being performed, the fact is notified to the system controller section 1 (step 3). The system controller unit 1 instructs the operation unit 2 and the CRT I / F unit 9 to display that reception is in progress (step 4), and stores the received encoded data in the secondary storage device 3 (step 5). . When the reception is completed, the operation unit 2 and the CRTI I / F unit 9 are instructed to display that the reception is completed (step 6), and the codec unit 5 is activated to reproduce the image data from the accumulated encoded data. (Step 7), the compressed data is expanded. Then, the decompressed data is expanded in the image memory unit 6. At this time, the codec section 5 notifies the system controller section 1 for each fixed processing unit (steps 8 and 9).

When the codec section 5 is completed (step 10; Y, step 11), the system controller section 1
In response to this notification, the CRT I / F section 9 gives an instruction to display the processed data, and when printout is necessary (step 12), the plotter section is activated to print out (step 12). Step 13). When all the processes are completed, the fact is displayed on the operation unit 2 and the process returns to the standby state (step 14). When the color transmission capability is not available, the system controller unit 1 is notified of the fact while performing the receiving operation. The system controller unit 1 instructs the operation unit 2 and the CRT I / F unit 9 to display that data is being received, and stores the received encoded data in the secondary storage device 3.

When the reception is completed, the operation unit 2 and the CRT I / F unit 9 are instructed to display that the reception is completed, and the binarization processing unit 11 is operated to reproduce the image data from the accumulated encoded data. Start and decompress compressed data. The decompressed data is expanded in the image memory unit 6 in the designated color. At this time, the binarization processing unit 11 notifies the system controller unit 1 for each fixed processing unit. Upon receiving this notification, the system controller unit 1 receives the CRTI
/ Instruct the F section 9 to display the processed data,
When printout is necessary, the plotter unit 7 is activated to print out. When all the processes are completed, the fact is displayed on the operation unit and the process returns to the standby state.

At the beginning of transmission, the system controller 1 detects the instruction from the operation section 2 when there is a transmission instruction (step 1) and the transmission instruction is given (step 15). First, the scanner section 4 is activated (step 16). ). The scanner unit 4 starts reading an image, reads 8-bit RGB signal data at the same time, and sequentially writes them in the image memory unit 6 (step 1
7) The encoded data is stored in the secondary storage device 3 (step 18). When the scanner unit 4 finishes storing all the data, the system controller unit 1 instructs the ISDNI / F unit 8 to confirm the function of the partner device with the session protocol CSS / RSSP, and if there is a color transmission capability. Then, Session Protocol CDCL / RDCLP
The color transmission function is confirmed at (step 19, step 20, step 21).

If it has color transmission capability, it instructs the codec section 5 to start encoding. The codec unit 5 takes in image data from the image memory unit 6 and performs an encoding process. The encoded information is sent to the system controller unit 1 and is once stored in the secondary storage device 3 here. Then, the system controller unit 1 activates the ISDNI / F unit (step 22) and transfers the encoded data through the communication line. When the transfer is completed (step 23), the ISDNI / F unit 8 notifies the system controller unit 1 to that effect. When the system controller unit 1 receives the report of the transfer end, the operation unit 2 and the CRTI I / F unit 8
And then return to the standby state (step 2
4). When "there is no color transmission capability", the binarization processing unit 11 is instructed to start encoding.

The binarization processing unit 11 takes in image data from the image memory unit 6 and performs an encoding process. The encoded information is sent to the system controller unit 1 where it is once stored in the secondary storage device 3. Then, the system controller unit 1 activates the ISDNI / F unit 8 and transfers the encoded data through the communication line. ISDNI /
When the transfer is completed, the F section 8 informs the system controller section 1 to that effect. When the system controller unit 1 receives the report of transfer completion, the operation unit 2 and the CRTI I / F unit 9
The display is instructed to and the unit returns to the standby state.

Next, the binarization process will be described. The image memory unit 6 is loaded with information of 8-bit RGB signals per pixel. The simplest binarization method is
There is a method of adopting the largest value or the smallest value of the RGB signals as the representative value of the pixel and binarizing it with a designated threshold value. In addition, the representative value may be an average value of RGB signals. By setting the threshold for each RGB signal, the expressive power when binarized is improved. There is a method of setting a threshold value for each 8-bit value of each RGB signal, binarizing each of the 8-bit values, and then binarizing the 3-bit data by or, and, or the arithmetic mean.

As a method of obtaining a representative value of each pixel, there is a method of utilizing brightness. For each 8-bit value of the RGB signal, a table in which 256 brightness values are written for each RGB signal is prepared, and the brightness is determined using this table. This makes it possible to accurately binarize the brightness of each color. Further, by performing dither processing instead of binarizing with a designated threshold value, it is possible to represent a binary halftone of a color image. In the case of binarizing with a predetermined threshold value, the character part can be expressed neatly, but the halftone part cannot be expressed well. On the contrary, when binarizing by the dither process, the halftone part can be expressed well, but the character part cannot be expressed well.

The character part generally has a certain fixed RGB signal pattern, and pixels having the fixed pattern are binarized by a predetermined threshold value, and the other parts are dithered to significantly improve the image quality. Can be improved.

[0028]

As described above, according to the present invention, the color facsimile and the monochrome facsimile can communicate with each other, so that the communication with the monochrome facsimile does not impose an extra economic burden on the user. Further, binarization of a color image can be performed at high speed and low cost. Further, since the threshold value can be set for each color element of the RGB signal, finer control of the binarization processing can be performed. Further, by calculating the lightness of the color image and performing the binarization process according to it, the binarization process can be performed extremely finely. Also, the halftone information of the color image can be expressed more accurately. Further, the binarization process using the threshold value of the halftone image results in a black solid image, and halftone information cannot be reproduced at all. Also, when dithering a binary image such as characters,
It is possible to eliminate the harmful effects such as the edges of characters being blurred and becoming difficult to see.

[Brief description of drawings]

FIG. 1 is a diagram showing a block configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a codec section.

FIG. 3 is a diagram showing an outline of operation of a codec section.

FIG. 4 is a diagram showing an outline of a configuration of a binarization processing unit.

FIG. 5 is a diagram showing an outline of an operation of a binarization processing unit.

FIG. 6 is a flowchart showing a procedure of operations according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... System controller 2 ... Operation part 3 ... Secondary storage device 4 ... Scanner part 5 ... Codec part 6 ... Image memory part 7 ... Plotter part 8 ... ISDNI / F part 9 ... CRTI / F part 10 ... CRT 12 ... CPU 13 ... Memory 14 ... DSP 15 ... DMA 16 ... FIFO 17 ... BUS I / F 21 ... CPU 22 ... Memory 23 ... BUS I / F

Claims (6)

[Claims] 1. A color image transmission apparatus including an image memory device for storing a read color image or a received color image, comprising a binarization processing device for converting a color image stored in the image memory device into a monochrome image. A color image transmission device characterized by the above. 2. A color image transmission device including an image memory device for storing a read color image or a received color image, comprising a control device for outputting a specific color when a monochrome image is received. And color image transmission device. 3. A color image is read in RGB, and RGB is read.
A binarization processing method characterized in that each element of a signal is combined by or or and, or arithmetically averaged and binarized by a predetermined threshold value. 4. A color image is read by RGB signals and R
A threshold value is set for each element of the GB signal, and the binarized value corresponding to the RGB signal after binarizing the RGB signal with each threshold value is combined with or or and, or added. A binarization processing method that performs binarization conversion with a predetermined threshold value. 5. A color image is read by RGB signals and R
A binarization processing method in which the brightness corresponding to the value of each element of the GB signal is combined with or or and, or arithmetically averaged and binarized with a predetermined threshold value. 6. A color image is read by RGB signals and R
A threshold value is set for each lightness corresponding to the value of each element of the GB signal, and the binarized value after binarizing with each threshold value is o
A binarization processing method for performing binarization conversion with a predetermined threshold value by combining or adding with r or and.