JPH0575881A - Picture transmission device - Google Patents

Abstract

PURPOSE:To reduce transmission quantity by transmitting only necessary color information of picture data read from a scanner. CONSTITUTION:A scanner part 5 inputs picture data from an original. A cordec part 6 performs a coding for inputted picture data and a decoding for compression data transmitted via a communication line. An operation part 1 has a panel which receives instructions from users and displays the state of a machine. A secondary storage device 2 stores encoded picture data. This device has a mode transmitting only picture data of a color designated on a transmission side as well as a mode making picture data to multicolor multi-level data and transmitting all colors picture data.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an image transmission device, and more particularly to an image transmission device for transmitting color image data. For example, it is applied to a color facsimile or the like.

[0002]

2. Description of the Related Art Conventionally, as a communication device system for exchanging data of a plurality of colors, a facsimile device having a reading means and a recording means of the data of a plurality of colors has been used. In this case, the read multi-color data is transmitted from the one facsimile machine on the transmitting side, and the received data is recorded on the other facsimile machine on the receiving side. When such a facsimile apparatus transmits two-color data, for example, the red information and the black information are simultaneously encoded by the reading means for reading the red color and the black color. Therefore, the information of the encoded data can be obtained. The amount increases. In this case, usually, there is a problem that the transmission time becomes longer than that of a facsimile apparatus which transmits data of only one color.

In order to solve this point, for example, a "communication device system" has been proposed in Japanese Patent Application Laid-Open No. 2-63374. According to this publication, the first communication device specifies only one color to be read from the original and reads the original, and the read information is transmitted to the second communication device. The second communication device uses the first communication device. The received information is output based on the color attribute of the information. However, there is a drawback that only one specific color can be transmitted at the time of transmission. In general, a color image has a very large amount of information as compared with image data of a single color, and in an image transmission device typified by a facsimile, it is considered to be a big problem from the viewpoint of speed and cost to reduce the transmission amount as much as possible. ing.

[0004]

[Object] The present invention has been made in view of the above-mentioned circumstances, and an image in which the amount of transmission is reduced by transmitting only necessary color information in the image data read from the scanner. The purpose is to provide a transmission device.

[0005]

In order to achieve the above object, the present invention provides (1)
A scanner unit for inputting image data from the original,
ISDN for transmitting / receiving encoded data via a communication line
An I / F unit, a codec unit that encodes image data input from the scanner unit and decodes compressed data sent via the communication line, and an image memory for holding the image data Section, a plotter section for outputting the image data, a CRT I / F section for outputting the image data to a CRT, a system controller for controlling these sections, and a machine state in response to an instruction from a user. And a secondary storage device for accumulating encoded image data, the image data is multi-color multi-gradation data, and image data of all colors is transmitted. In addition to the mode, the transmission side has a mode in which only the image data of the color specified is transmitted. Further, (2) the image data of each color is made into binary image data, and the transmission side specifies Transmitting only image data of a predetermined color, and (3) transmitting the image data of the color component designated by the transmission side among the image data as full-color image data, and further (4) above. In (3), the full-color image data is decomposed into a luminance component and a color difference component, and only the luminance component is transmitted. Hereinafter, description will be given based on examples of the present invention.

FIG. 1 is a block diagram for explaining an embodiment of an image transmission apparatus according to the present invention, in which 1 is an operating unit and 2 is
Is a secondary storage device, 3 is a system controller, 4 is an IS
DN I / F section, 5 scanner section, 6 codec section, 7
Is a plotter section, 8 is an image memory section, and 9 is a CRT I / F
Reference numeral 10 is a CRT, and 11 is a system bus. The system controller 3 is responsible for starting the operation of each unit and managing the state, and is composed of a CPU, a memory, a BUS I / F, and the like. It also controls the operation unit 1 and the secondary recording device 2 described below and transfers data between these devices. The operation unit 1 starts FAX, inputs a telephone number,
It is composed of various keys for operating other FAX functions, a liquid crystal panel capable of displaying various operating procedures and various machine statuses, and other display devices.

The secondary storage device 2 is a magnetic disk used for storing encoded data and storing registered telephone numbers. The scanner unit 5 is a device that inputs image data from a document, and includes a light source, a photoelectric conversion element, an A / D converter, and a B
It is configured by a well-known technique such as US I / F. A filter is used to obtain color image data, and in the cases of claims 1 and 2, black, red, blue, and other colors are combined, and in the cases of claims 3 and 4, color components of three RGB colors are simultaneously obtained. Reading. The obtained data is sent to the image memory unit 8 through the BUS I / F.

The codec section 6 transfers image data to and from the image memory section 8 and compresses and expands the image data. When the image data is binary, MH (Modified Huffman) method, MR (Modified Read) method, etc. are encoded, and when it is a multi-valued image, it will be described later in DC.
T (Discrete Cosine Transform)
Performs compression by calculation. It also performs color conversion between RGB and YCbCr. The plotter unit 7 includes a DMA (Direct Memory Access, BUS).
It is composed of an I / F, a color ink ribbon, a thermal head, a paper transport mechanism, and the like. Image data is fetched from the image memory section 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 image memory unit 8 is a frame buffer for storing uncompressed input / output image data composed of a BUS I / F and a memory. It is used to store image data read by the scanner unit or image data output to the printer unit. The image memory unit has a memory configuration as shown in FIGS. In the case of the first aspect, as shown in FIG. 3, the multi-tone memory configuration corresponds to read colors such as black, red, and blue. Claim 2
In the case of item, the memory configuration corresponds to the read color as in claim 1, but binary data for each color is used. Claim 3
In the case of the claim and the claim 4, as shown in FIG. 4, a memory structure of 8 bits for each RGB is formed.

The ISDN I / F unit 4 includes an I / F circuit for the ISDN line, a CPU, a memory, and a BUS I / F.
Composed of. Here, control of a protocol at the time of communication and transmission / reception of compressed encoded data are performed. CRT
The I / F unit 9 includes a display memory for displaying on the CRT 10, a DMA, a display timing controller, and a D / F.
It is composed of an A converter and a BUS I / F. DMA
The data is fetched from the image memory to the display memory via the BUS I / F, converted into an analog signal by the D / A converter, and displayed on the CRT 10.

FIG. 2 is a diagram for explaining the DCT. DCT operation is DCT (Discrete Cosine Transf
orm: Discrete Cosine Transform) is one of the orthogonal transforms,
It has been applied to the still image coding system and is currently ISO and CCI.
Standardization is underway at TT. 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 represented by f (i, j) (where i = 0
.About.7, j = 0 to 7) and the DCT mapping F (u, v) is expressed as follows.

[0012]

[Equation 1]

The equation (1) is called a DCT coefficient and is given by an 8 × 8 coefficient matrix. Here, C (w) = 1 / √2 (when w = 0) or 1 (when w = 1, 2, ..., N−1). Also, the reverse D
CT is calculated by the following formula.

[0014]

[Equation 2]

The 8 × 8 coefficient matrix F (u, v) is u,
The larger v corresponds to the conversion coefficient of the higher frequency component of the spatial frequencies included in the image, and F (0,
0) corresponds to the coefficient of the DC component. That is, in the top row, the coefficient of the horizontal component of the spatial frequency contained in the image is arranged in order from the lowest frequency, and in the leftmost column, the frequency of the coefficient 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.

5 and 6 are flowcharts for explaining the operation of the image transmission device according to the present invention. In the following, each step will be described separately for transmission and reception. The control of the entire flow is performed by the system controller. Further, in the first aspect, the case where there are two kinds of colors of an image read by the scanner, black and red, will be described as an example. First, the following operation is performed during reception. step1 : Upon reception, when the ISDN I / F unit detects an incoming call, it notifies the system controller of that fact while performing the receiving operation. At this time, the system controller can obtain the color designation information sent from the sending side. step2 : The system controller is the operation unit and
The / F section is instructed to display that it is being received. step3 : The received encoded data is accumulated in the secondary storage device.

[0017] step4: instructing display of the reception has been completed on the operation unit and the CRT I / F unit when receiving ends to the system controller. step5 : In order to reproduce the image data from the accumulated encoded data, the system controller activates the codec unit and decompresses the compressed data. The decompressed data is expanded in the image memory area of the color designated by the color designation information. For example, if the color designation "red" has been made, the expanded image data is expanded in the red image memory area. If the color is not specified, it is expanded in the image memory area of all colors. steps 6 and 7 : At this time, the codec section notifies the system controller of each fixed processing unit. Upon receipt of this notification, the system controller issues an instruction to display the processed data to the CRT I / F section and displays the received image on the CRT.

Steps 8 and 9 : If all the compressed data have been decompressed, then the system controller shifts to a print instruction acceptance state, and to that effect the CRT I / F
Give instructions to the department. Steps 10, 11, 12 : When a print instruction is detected from the operation unit, the system controller activates the plotter unit, and the plotter unit reads the image data from the image memory unit and outputs it. Step 13 : If the instruction not to print is detected in Step 10, the plotter unit cannot be activated. When all the processing is completed, the fact is displayed on the operation unit and the CRT I / F unit, and the process returns to the standby state.

Next, at the time of transmission, the following operation is performed. steps 14 and 15 : At the time of transmission, the system controller detects an instruction from the operation unit, and first activates the scanner. The scanner unit captures images as image data of two colors, black and red, and sequentially writes them in the memory. At this time, the black image data is expanded in the black image memory area and the red image data is expanded in the red image memory area as multi-tone data. step16 : At the same time, the system controller gives an instruction to display the transmission color designation to the operation unit and the CRT I / F unit, and shifts to the transmission color acceptance state. step17 : Here, when the color designation information is obtained from the operation unit, the system controller determines that only that color is transmitted. In other cases, it is determined that the image information of all colors should be transmitted. Therefore, when the image memory has accumulated a certain amount of image data read from the scanner, the system controller instructs the codec section to start encoding.

Steps 18 to 21 : The codec unit takes only the image data of the designated color from the image memory of the color and performs the encoding process. In the case of no designation, encoding is performed on image data of all colors. The encoded information is sent to the system controller, where it is stored once in secondary storage. Then, when the operations of the scanner unit and the codec unit are completed, the storage in the secondary storage device is completed. step22 : System controller is ISDN I / F
The unit is activated and the encoded data is transferred through the communication line. step23 : The ISDN I / F section notifies the system controller of the completion of the transfer. step24 : When the system controller receives the report of the end of transfer, it issues a display instruction to the operation section and the CRT I / F section and returns to the standby state.

In the above embodiment, the image data is multi-valued data of two colors of red and black, but it is also possible to use image data of three or more colors (m pieces). In that case, n out of m
It is possible to send data of each color. (M, n =
1, 2, ..., M> n) Further, the image data can be binary image data as in claim 2. Further, as in claim 3, the image data can be full color, that is, data of 8 bits of RGB each, and in this case, it is also possible to transmit only data of two colors of R and B of RGB. At this time, the scanner reads the input image as 8-bit RGB data and writes it in the image memory. Further, in claim 4,
The RGB image data read by the scanner is converted into a luminance component (Y) and a color difference component (Cb, Cr) in the codec section, and only the luminance component (Y) is sent. The image data to be transmitted is monochrome multi-tone image data, but most of the image information to be transmitted can be transmitted, and the data transmission amount can be very small.

[0022]

As is apparent from the above description, according to the present invention, when transmitting image data of a plurality of colors, by transmitting only the image data of the color designated by the transmitting side, the transmission speed is increased and data transmission is required. The cost can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of an image transmission device according to the present invention.

FIG. 2 is a diagram for explaining DCT.

FIG. 3 is a diagram showing a memory configuration of an image memory.

FIG. 4 is a diagram showing another memory configuration of the image memory.

FIG. 5 is a flowchart for explaining the operation of the image transmission device according to the present invention.

FIG. 6 is a flowchart continued from FIG.

[Explanation of symbols]

1 ... Operation part, 2 ... Secondary storage device, 3 ... System controller, 4 ... ISDN I / F part, 5 ... Scanner part, 6 ... Codec part, 7 ... Plotter part, 8 ... Image memory part, 9 ...
CRT I / F section, 10 ... CRT, 11 ... System bus.

Claims (4)

[Claims] 1. A scanner unit for inputting image data from a document, an ISDN I / F unit for transmitting and receiving encoded data via a communication line, and encoding of image data input from the scanner unit. A codec section for decoding compressed data sent via the communication line, an image memory section for holding the image data, a plotter section for outputting the image data, and the image data CRT I / F section for outputting the data to a CRT, a system controller for controlling these, an operation section having a panel for displaying the machine status in response to a user's instruction, and storing encoded image data In addition to a mode in which the image data is multi-color multi-gradation data and the image data of all colors is transmitted,
An image transmitting apparatus having a mode for transmitting only image data of a color designated by a transmitting side. 2. The image transmitting apparatus according to claim 1, wherein the image data of each color is binary image data, and only the image data of the color designated by the transmitting side is transmitted. 3. The image transmitting apparatus according to claim 1, wherein the image data is full-color image data, and only the image data of the color component designated by the transmitting side is transmitted. 4. The image transmission device according to claim 3, wherein the full-color image data is decomposed into a luminance component and a color difference component, and only the luminance component is transmitted.