JPH04371074A - Method and device for image data conversion - Google Patents

Abstract

PURPOSE:To enable communication between an image filing device compressing and storing a binary image and a transmitter/receiver of a multivalued image by providing a binary image extension means and a multivalued image compression means. CONSTITUTION:In a communication adapter, a binary image extension means 102 receives the compressed codes of the binary image from an image filing device 101, restores them into the original binary image, and transmits them to a density restoration means 103. The restoration means 103 calculates the density corresponding to the number of color picture elements in prescribed area, and a multivalued image compression means 104 encodes the multivalued image received from the restoration means 103, compresses them and transmits them to a communication interface 108. The interface 108 transmits them to a work station, etc., via a network 109. Thus, since data conversion is available between the compressed codes of the color binary image and that of the color multivalued image, the communication between the image filing device compressing and storing the binary image and the transmitter/receiver of the multivalued image can be enabled.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication adapter for image filing devices connected via a network, and more particularly to a device for converting data between a compression code for a color binary representation image and a compression code for a color multivalue representation image. Regarding.

0002

2. Description of the Related Art Conventionally, a common communication protocol has been widely used for communication of monochrome binary images. An example is that used in facsimile machines. By using this facsimile communication protocol, images can basically be freely communicated between devices of different models. In particular, as the data format of the image itself, the international standard CCITT (International Telegraph and Telephone Consultative Committee)
H (Modified Huffman) code, MR (
Modified READ) code, MMR (Modi
MR) codes are widely used. These codes are compressed monochrome binary images, and each code is slightly different, but basically they are predetermined short codes for the points of change where the color of a pixel in a monochrome binary image changes from white to black or from black to white. This is a method of assigning codes. However, while the MH code encodes and compresses each horizontal line, the MR code and MMR code also encode and compress the continuity of pixel colors in the vertical direction. In addition, when encoding with the continuity of pixel colors in the vertical direction, if the image of one horizontal line is disturbed due to a communication error, subsequent images will also be disturbed, so in MR code, only the horizontal line unit is encoded every few lines. Insert to stop image distortion. The MMR code assumes the use of a dedicated line, and the idea is that communication errors will be corrected in the communication system and the errors will disappear, so coding is not inserted only in units of horizontal lines. Because of this encoding method, the compression rate is highest in the order of MH code, MR code, and MMR code.Facsimile machines that use MH code and MR code are called G3 facsimile machines, and facsimile machines that use MMR codes are called G4 facsimile machines. It is called a facsimile machine. Note that since compressed data is called a code, the process of compression is also called encoding, and the process of restoring the compressed code to the original image is also called decompression.

As described above, it is possible to communicate monochrome binary images according to the international standard for facsimile devices, but there are also devices that perform data conversion, as disclosed in Japanese Patent Application Laid-Open No. 2-2755. Although direct communication is possible between G3 facsimile machines, we focused on the fact that the MMR code of G4 facsimile machines has a higher compression rate and requires shorter communication time than the MH/MR code of G3 facsimile machines. It is converted into a code and communicated. FIG. 2 is a block diagram of a system using this device. G3
G3 FAX201 and 205 which are facsimile machines
When communicating, the MH/MR code and MMR code conversion devices 202 and 204 are used, and the network 109 uses M
Communicate using MR code. Of course, it is also possible to communicate with the G4 FAX 203, which is a G4 facsimile machine. There is only one data format for monochrome binary images that can realize data conversion of compression codes for such images, and that is MH/MR.
This is because a code can be expanded into an image and then compressed into an MMR code, or an MMR code can be expanded into an image and then compressed into an MH/MR code.

However, for color images, there are many types of image data formats, and there are also multiple types of compression codes. Image data formats include, for example, binary expression images and multi-value expression images. FIG. 8 is an explanatory diagram of the data format of a binary representation image. In a binary expression image, the data width of one pixel is 1 bit, and since only binary values can be expressed, the density is expressed by the number of colored pixels within a certain area. That is, an image with a large number of hatched pixels in FIG. 8 has a high density, and an image with a small number of hatched pixels has a low density. Such an image is generally called a dithered image. In a color image, by dithering each of the three surfaces: red R surface, green G surface, and blue B surface,
, B have their respective densities. Furthermore, 3 of R, G, and B
By overlapping the surfaces, various colors are produced from the density of R, G, and B. FIG. 9 is an explanatory diagram of the data format of a multivalued image. In a multivalued image, the data width of one pixel is multiple bits, for example 8
Since there are bits, multilevel density can be expressed in units of one pixel. Therefore, in a color image, the three surfaces of R, G, and B are simply superimposed to produce various colors based on the densities of R, G, and B. These image data formats are selected based on the data amount compression rate and color expressiveness. On the other hand, as a type of compression code, there is a method of assigning the above-mentioned MH code, MR code, and MMR code to each of the three R, G, and B sides of a binary image. For multilevel images, JPEG (JointPhoto) is a joint organization of CCITT and ISO (International Organization for Standardization).
Graphic Experts Group) D
CT (Discrete Cosine Transform)
There is a rm (discrete cosine transform) method. This method is explained in CQ Publisher's Interface Magazine, September 1990 issue, pages 247 to 250. others,
Workstations and personal computers use a color code and an LUT that represents the actual color from that color code.
(Look Up Table) may be used as an image data format or compression code.

[0005]

In the above-mentioned prior art, by using a compression code for facsimile machines, which is an international standard, in monochrome binary image communication, it is possible to easily communicate between different devices. In particular, no matter what kind of code to code conversion, a monochrome binary image can be decompressed to the original image, and then compressed again to another code.
Conversion is possible. However, data conversion by expanding to the original image generally requires memory capacity sufficient to store one page's worth of image data, and A4 size 200DPI (Do
t Per Inch) requires a large capacity of about 500 Kbytes.

However, in color image communication, communication is difficult because there are many types of image compression codes. Furthermore, there are many types of image data formats, so even if the original image is restored, such as a monochrome binary image, it is difficult to immediately recompress it into another code due to the difference in image data format. There was a problem.

A first object of the present invention is to enable data conversion and communication between a compression code for a color binary representation image and a compression code for a color multivalue representation image. A second object of the present invention is to enable high-speed communication with a communication partner that can receive multiple types of compression code formats. A third object of the present invention is to enable transmission and reception in a plurality of compression code formats depending on the communication partner device serving as the destination or source.

[0008]

[Means for Solving the Problems] In order to achieve the above first object, the present invention provides means for receiving a compressed code of a binary representation image from an image filing device, and means for decompressing the received code into a binary representation image. , a means for restoring the density of an expanded binary expression image and converting it into a multi-value expression image, a data conversion means for encoding and compressing the converted multi-value expression image, a means for transmitting the compressed code, or a means for converting the multi-value expression image into a multi-value expression image. Means for receiving a compression code, means for expanding the received code into a multi-value representation image, means for dithering the expanded multi-value representation image and converting it into a binary representation image, and encoding and compressing the converted binary representation image. data inverse conversion means and means for sending the compressed code to the image filing device.

In order to achieve the second object, the present invention provides a means for comparing the data amount of a compression code for a binary representation image and a compression code for a multivalue representation image, and a means for comparing the data amount of a compression code for a binary representation image and a compression code for a multivalue representation image, Use select and send methods.

In order to achieve the third object, the present invention uses selection means for communicating without going through the data conversion means and the data inverse conversion means. Furthermore, means for inputting the compression code type of the binary expression image or multi-value expression image that can be received at the destination together with the destination address, or table means for holding it is used.

[0011]

[Operation] The code received from the image filing device is
The code is temporarily restored to the image by means of decompression into a value representation image. This expanded binary representation image is converted into a recompressible image data format by means of restoring the density and converting it into a multivalued representation image. Furthermore, data conversion means that encodes and compresses the converted multi-valued image can provide a compressed code for the multi-valued image that can be received by the destination, allowing communication. Further, when the communication partner transmits a compressed code of multi-value expression, the code is temporarily restored to an image by means of expanding the received code into a multi-value expression image. This decompressed multivalued image is converted into a recompressible image data format by means of dithering and converting it into a binary image. The data inverse conversion means that encodes and compresses the converted binary representation image can obtain a compressed code of the binary representation image that can be stored by the image filing device, so that communication is possible.

[0012] Generally, the time required for communication is proportional to the amount of data to be communicated, and inversely proportional to the communication line speed. Therefore, communication can be made faster by reducing the amount of data to be communicated without increasing the speed of the communication line itself. The data amount of the two types of codes is determined by means of comparing the data amount of the compression code of the binary expression image and the compression code of the multi-value expression image, and the code with the smaller compared data amount is selected and transmitted. By means of this means, it is possible to reduce the amount of data to be communicated and speed up communication.

[0013] The data conversion means converts the compression code of the binary expression image into the compression code of the multi-value expression image, and the selection means for communicating without going through the data inverse conversion means in the opposite direction, allows the multi-value expression image to be converted into a multi-value expression image. In addition to the compressed code of , it is now possible to transmit and receive compressed codes of binary representation images, so it is possible to communicate in two types of compressed code formats. Furthermore, the destination's receivable 2
By means of inputting the compression code type of the value expression image or the multi-value expression image together with the destination address, or by the table means for holding it, it is possible to transmit and receive the compressed code that can always be communicated depending on the communication partner.

[0014]

[Embodiment] An embodiment of the present invention will be explained below with reference to FIG. FIG. 1 is a block diagram of a color image data conversion mechanism. The image filing device 101 is a binary expression image decompressor 102
, density restoration 103, multivalue expression image compression 104, binary expression image compression 105, dithering 106, multivalue expression image expansion 1
07, communicates with other devices through a communication adapter consisting of a communication interface 108 and a network 109.

The image filing device 101 encodes and compresses a binary representation image input from a scanner device or the like.
The information is stored in a large capacity storage device such as an optical disk device, and displayed on a display screen or printed with a printer device as needed. The image filing device 101 sends the compressed code of the stored image to the binary expression image decompression 102, and from the binary expression image compression 105 to the network 109.
Receives the compression code of the image received via.

Binary expression image expansion 102 and density restoration 103
, multi-value expression image compression 104, binary expression image compression 105, dithering 106, multi-value expression image expansion 107, and communication interface 108 are components of a communication adapter. The binary expression image expansion 102 receives the compression code of the binary expression image from the image filing device 101, restores it to the original binary expression image, and sends it to the density restoration 103. CCITT's MH code, MR code, M
There is an MR code. The density restoration 103 is performed using a density restoration mask 1 according to the number of color pixels in a certain area as shown in FIG.
001 and an adder to calculate the concentration in that area. This density restoration process will be explained later. Furthermore, by calculating the density of the entire image, the binary representation image is converted into a multivalue representation image. The converted multivalued image is sent to multivalued image compression 104. The multivalued image compression 104 encodes and compresses the multivalued image received from the density restoration 103 . JPEG is the compression encoding format for multivalued images.
There is a DCT method. The compressed code is sent to the communication interface 108, and the communication interface 108 sends it via the network 109 to the WS/PC 110, which is a workstation or personal computer, or to the color facsimile device FAX 111, which can receive the compressed code of a color multivalued image.

On the other hand, the communication interface 108 is a WS/
Network 10 from PC 110 or FAX 111
The compression code of the multi-valued image is received via 9 and sent to the multi-valued image decompression 107 . The multi-value expression image decompression 107 restores the compressed code to the original multi-value expression image and sends it to the dithering 106. In dithering 106, as shown in FIG. 11, a dithering matrix 1101 is applied to the density of each pixel of the multi-valued image, the color of the pixel is determined, and the multi-valued image is converted into a binary image. This dithering process will be explained later. The converted binary representation image is sent to the binary representation image compression 105. Binary expression image compression 105 encodes and compresses the binary expression image received from dithering 106. The compressed code is sent to the image filing device 101 and stored in an optical disk device or the like.

As explained above, according to this embodiment, data can be converted between the compression code of a color binary representation image and the compression code of a color multivalue representation image using the communication adapter. Communication is possible between an image filing device that compresses and stores images and a device that can send and receive compression codes for multivalued images.

Another embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a block diagram of the color image data conversion mechanism.

The color image data conversion mechanism shown in FIG. 3 is obtained by adding a selector 301 and a selector 302 to the color image data conversion mechanism shown in FIG. The selector 301 selects whether to send the compression code received by the communication interface 108 from the network 109 directly to the image filing device 101, or to expand the image once and then compress it again before sending it to the image filing device 101. That is, when receiving a compression code of a multivalued image from the network 109, the communication interface 108, multivalued image expansion 107, dithering 106, and binary image compression 105 are used.
The selector 301 selects the data converted into the compressed code of the binary representation image via the image filing device 101.
The compressed code of the multivalued image can be received. Further, when receiving a compressed code of a binary representation image from the network 109, the selector 301 selects the data from the communication interface 108, and the image filing device 101 selects the data from the communication interface 108.
The compressed code of the binary representation image can be received.

The selector 302 is the image filing device 1
The compression code sent from 01 to the network 109 via the communication adapter can be sent directly to the network 109, or the image can be decompressed once and then compressed again.
You can choose whether to send it to In other words, when transmitting the compression code of a multivalued image to the network 109, 2
The selector 302 selects the data converted into the compression code of the multivalued image via value expression image expansion 102, density restoration 103, and multivalued image compression 104, and sends it to the communication interface 108, so that the multivalued image is compressed. Can send codes. Furthermore, when transmitting the compressed code of the binary representation image to the network 109, the selector 302 selects the data from the image filing device 101 and sends it to the communication interface 108, so that the compressed code of the binary representation image can be transmitted. Switching between the selector 301 and the selector 302 is performed when the operator inputs the communication partner using the keyboard or the like, depending on the model of the communication partner.

As explained above, according to this embodiment, data can be converted between the compression code of a color binary representation image and the compression code of a color multivalue representation image using the communication adapter, and there is also a path where data is not converted. can also be selected, allowing communication between the image filing device that compresses and stores binary images, and devices that can send and receive compression codes for binary images and devices that can send and receive compression codes for multivalued images. can.

Another embodiment of the present invention will be described below with reference to FIG. FIG. 4 is a block diagram of the color image data conversion mechanism.

The color image data conversion mechanism shown in FIG. 4 is obtained by adding a data amount comparator 401 to the color image data conversion mechanism shown in FIG. 3, and using a selector 402 instead of the selector 302. In addition, in FIG. 4, the binary representation image compression 1 of FIG.
05, dithering 106, multi-value expression image expansion 107, and selector 301 are omitted because they do not require explanation, but are actually provided. The data amount comparator 401 receives the compression code of the binary representation image from the image filing device 101 and the compression code of the multivalued representation image from the multivalued representation image compression 104.
The data amounts are compared and the comparison result is sent to the selector 402.
send to The selector 402 selects a compression code with a smaller amount of data according to the comparison result from the data amount comparator 401 and sends it to the communication interface 108 .

The data amount comparison and selection mechanism shown in FIG. 12 is a specific example of the structure of the data amount comparator 401 and selector 402 shown in FIG. A compression code for a binary representation image and a compression code for a multivalued representation image are received by a counter 1201 and a code detector 1204, and a counter 1202 and a code detector 1205, respectively, and the selected compression code is output from a data transfer device 1208. A counter 1201 and a counter 1202 sequentially count the data amount of the received compressed code, and a comparator 1203 compares the data amount. The code detector 1204 and the code detector 1205 detect the terminal code attached to the end of each compression code, and at the time of detection, the data transfer unit 120
Tell it to 8. Buffer 1206 and buffer 1207 temporarily store each compression code. When both the code detector 1204 and the code detector 1205 detect the terminal code of the compressed code, the data transfer unit 1208 checks the comparison result of the comparator 1203 and transfers the compressed code with a small amount of data to the buffer 1.
206 or the buffer 1207.

As described above, according to this embodiment, a compressed code with a small amount of data can be transmitted to the network 109 from among the compressed code for a binary image and the compressed code for a multi-valued image.

Another embodiment of the present invention will be described below with reference to FIG. FIG. 5 is a block diagram of a color image data conversion mechanism.

The color image data conversion mechanism shown in FIG. 5 is obtained by adding a destination address/code type table 501 to the color image data conversion mechanism shown in FIG. 4, and using a selector 502 instead of the selector 402.

[0029] Destination address/code type table 501
is a table that stores the addresses on the network 109 of devices connected to the network 109 and communicating with the image filing device 101 and the types of compression codes that the devices can receive. When an address is input, the type of compression code is obtained. It will be done. Here, it is assumed that the WS/PC 110 can only receive compressed codes for binary images, and that the FAX 111 can only receive compressed codes for multivalued images. When the image filing device 101 transmits to the WS/PC 110, when the operator inputs the address of the WS/PC 110, the destination address/code type table 501 stores a compressed code for a binary representation image to be transmitted. Therefore, the selector 502 selects the binary compression code from the image filing device 101 and transmits the compression code of the binary representation image to the WS/PC 110 via the communication interface 108 and the network 109. Image filing device 101
If the operator sends a message to FAX111, the operator
When address No. 11 is input, the destination address/code type table 501 stores the compressed code for the multi-valued image to be sent, so the selector 502 selects the data converted from the multi-valued image compression 104. A multilevel compression code is selected, and the compression code of the multilevel image is transmitted to the FAX 111 via the communication interface 108 and network 109. As explained above, according to this embodiment, there is an image filing device that compresses and stores binary expression images according to the communication partner device, a device that can receive compression codes of binary expression images, and a device that can receive compression codes of binary expression images, and It is possible to communicate accurately with both devices that can receive compressed codes.

Another embodiment of the present invention will be described below with reference to FIGS. 6 and 7.

FIG. 6 is a block diagram of a color image data conversion mechanism. Memory 601, communication interface 108
, a control device 602, a dithered density restoration 603, a multilevel image compression/expansion 604, and a binary image compression/expansion 605 constitute a communication adapter, and each part is mounted on one or more boards, and the image filing device 101 It is connected to the bus by installing it in the expansion board slot of the . Memory 601
is a storage device that stores binary expression images, multi-value expression images, compression codes for binary expression images, and compression codes for multi-value expression images. The dithered density restoration 603 reads out the binary expression image stored in the memory 601, converts the data into a multi-value expression image, and writes the data into the memory 601. Further, the multivalue representation image stored in the memory 601 is read out, data is converted into a binary representation image, and the data is written into the memory 601. The multivalued image compression/decompression 604 reads out and compresses the multivalued image stored in the memory 601 and writes the compression code to the memory 601, or reads the compression code of the multivalued image stored in the memory 601. The multi-level representation image is written into the memory 601. An example of an LSI that realizes such a function is CL550 manufactured by C-Cube. Binary image compression/
Decompression 605 reads the binary representation image stored in the memory 601, compresses it, and writes the compression code to the memory 601, or reads the compression code of the binary representation image stored in the memory 601, decompresses it, and converts it into binary representation. Image memory 60
Write to 1. An example of an LSI that realizes such a function is the HD63185 manufactured by Hitachi. Control device 60
2 is a device that controls the entire color image data conversion mechanism, which controls writing from the image filing device 101 to the memory 601 and from the memory 601 to the communication interface 108.
reading, starting and stopping dithered density restoration 603,
It controls starting and stopping of multivalued image compression/expansion 604, starting and stopping of binary image compression/decompression 605, and the like. A microprocessor such as Intel 80286 is used for such control.

FIG. 7 shows a processing flow of the color image data conversion mechanism of FIG. 6, which is executed by the control device 602. A compressed code of a binary representation image is sent from the image filing device 101 to the memory 601 by a binary code input 701 . The amount of compressed code data to be sent is limited to half the capacity of the memory 601, as shown in the memory configuration 709. In the binary code decompression activation, the binary image compression/decompression 605 decompresses the compression code of the binary expression image stored in the memory 601, restores it to the original image, and converts the compression code of the binary expression image stored in the memory 601 into the original image. Write so you don't erase it. Binary code expansion stop 703
stops the decompression process when the decompressed image becomes half of the memory 601. This results in a memory configuration 710. In the density restoration activation 704, the dithering/density restoration 603 performs density restoration processing on the binary representation image stored in the memory 601, converts it into a multivalued representation image, and writes the binary representation image in the memory 601 so as not to erase it. Concentration restoration stop 70
5 stops the density restoration process when the converted image becomes half of the memory 601. This allows memory configuration 71
Do like 1. The multilevel image compression activation 706 is performed by the memory 60.
The multi-value expression image stored in 1 is multi-value image compressed/expanded 60
4 performs compression processing, converts into a code of a multivalued image, and writes the multivalued image in the memory 601 so as not to erase it. A multivalued image compression stop 707 stops the compression process when the number of compressed codes becomes half of the memory 601. This results in a memory configuration 712. Communication is possible by sending the compressed code of the multi-valued image stored in the memory 601 to the communication interface 108 by the multi-level code output 708, and the communication interface 108 transmits the compressed code. Since it may not be possible to transmit all images in one process due to the limited capacity of the memory 601, the above process is repeated until transmission of all images is completed. 10 and 11 are explanatory diagrams of the dithered density restoration process 603. For methods of dithering and density restoration, see Japanese Patent Application Laid-Open No. 60-1426.
Publication No. 70 and Nikkei Electronics Magazine May 1, 1978
It is explained on pages 50 to 64 of the Japanese issue. In the density restoration process of converting the binary representation image to the multivalue representation image in Fig. 10, 2
Since the value expression image expresses the density by the number of color pixels within a certain area, the density is calculated using a density restoration mask 1001, a mask pattern that determines the relationship between the position of the color pixel and the density. Here, assuming that the density restoration mask 1001 has a size of 4 pixels in the vertical and horizontal directions, the binary expression image is cut out by 4 pixels in the vertical and horizontal directions and applied to the density restoration mask, and the density at each position is calculated. For the hatched color pixel 1002, the value of the pixel position 1003 of the density restoration mask 1001 is 2, and the hatched positions with values 4, 8, and 4 are also color pixels, so these 4 vertical and horizontal pixels The concentration of is 18 of the total value
becomes. In the dithering process of converting a multivalued image into a binary image shown in FIG. 11, a dithering matrix 1101 converts density into the number of color pixels within a certain area. Here, assuming that the size of the dithering matrix 1101 is 4 pixels in the vertical and horizontal directions, a multivalued expression image is cut out by 4 pixels in the vertical and horizontal directions and applied to the dithering matrix 1101 to determine the color at each pixel position. For density value 1102, the value of pixel position 1103 of dithering matrix 1101 is 7,
Since the density value 1102 of 8 is larger, it is colored. This is hatched in FIG. Furthermore, the four pixels at the center of the dithering matrix 1101 are also converted into the dithering matrix 110.
Each density of the multi-value expression image is greater than each pixel position of 1, so it is colored.

As explained above, according to this embodiment, the memory capacity used in each process is halved, so that color image data conversion processing can be realized with a small memory capacity through repeated processing.

Another embodiment of the present invention will be described below with reference to FIG. FIG. 13 is a block diagram of the color image data conversion mechanism. A multivalued image filing device 1301 performs binary expression image expansion 102, density restoration 103, and multivalued image compression 1.
04, binary expression image compression 105, dithering 106, multi-value expression image expansion 107, and communication interface 108, and a communication adapter and network 109 communicate with other devices.

The multivalued image filing device 1301 encodes and compresses a multivalued image input from a scanner device or the like, stores it in a large capacity storage device such as an optical disk device, and displays it on a display screen as necessary. , which is printed using a printer device. Multilevel image filing device 1
301 sends the compressed code of the stored image to the multivalued image decompression 107 and receives the compressed code of the image received via the network 109 from the multivalued image compression 104 .

Binary expression image expansion 102 and density restoration 103
, multi-value expression image compression 104, binary expression image compression 105, dithering 106, multi-value expression image expansion 107, and communication interface 108 are components of a communication adapter. Multi-valued image decompression 107 is carried out by multi-valued image filing device 130
1 receives the compression code of the multi-valued image, restores it to the original multi-valued image, and sends it to dithering 106. Dithering 10
6 converts the multivalued image into a binary image. The converted binary representation image is sent to the binary representation image compression 105. Binary expression image compression 105 encodes and compresses the binary expression image received from dithering 106. The compressed code is sent to the communication interface 108, and the code is sent to the communication interface 108.
is transmitted via the network 109 to a WS/PC 110 that is a workstation or personal computer, or to a color facsimile device FAX 111 that can receive compressed codes of color binary representation images.

On the other hand, the communication interface 108 is WS/
Network 10 from PC 110 or FAX 111
The compressed code of the binary representation image is received via 9 and sent to the binary representation image decompression 102. The binary expression image expansion 102 restores the compressed code to the original binary expression image and sends it to the density restoration 103. Density restoration 103 converts a binary expression image into a multivalue expression image. The converted multi-value expression image is subjected to multi-value expression image compression 104.
send to The multi-value expression image compression 104 encodes and compresses the multi-value expression image received from the density restoration 103. The compressed code is sent to the multilevel image filing device 1301 and stored in an optical disk device or the like.

As explained above, according to this embodiment, data can be converted between the compression code of a color binary representation image and the compression code of a color multivalue representation image using the communication adapter. Communication is possible between an image filing device that compresses and stores images and a device that can send and receive compression codes for binary representation images.

Another embodiment of the present invention will be explained below with reference to FIG. FIG. 3 is a block diagram of the color image data conversion mechanism.

The color image data conversion mechanism shown in FIG. 3 has a selector 301 so that it can receive compression codes for binary images and multivalue images. If two types of compression codes can be received in this way, and the communication partner can also transmit two types of compression codes by having a mechanism equivalent to the selector 302, the two types of compression codes can be freely selected as shown below. and communicate. Since the image filing device 101 is a device that processes binary representation images,
Initially, it is agreed in advance with the communication partner to receive the compressed code of the binary representation image. As a result, the selector 30
1 can select the compression code of the communication interface 108, so the processing of multilevel image expansion 107, dithering 106, and binary image compression 105 is unnecessary, and the image is displayed on the image filing device 101 after receiving the compression code. The time it takes to do this can be shortened. The operator checks the received image on the display screen of the image filing device 101 and ends the communication if there is no problem with the image quality. If an image of a different quality is required, an operator operates the communication interface 108 to request the communicating party to retransmit the same image using a compression code of a multi-valued image. At this time, the operator causes the selector 301 to select a compression code from the binary image compression 105. When a compression code of a multivalued image is received from a communication partner, it takes some time to convert the compression code, but it is possible to obtain a different image quality.

As described above, according to this embodiment, the same image of different image quality can be easily received, so the operator can select the image quality according to his/her preference.

[0042]

According to the present invention, data can be converted between the compression code of a color binary representation image and the compression code of a color multivalue representation image in the communication adapter of the image filing device. This has the advantage of being able to communicate with other color image processing devices. Furthermore, since the compression code format with the smallest amount of data can be selected for communication with a communication partner that can receive a plurality of types of compression code formats, there is an effect that communication can be performed at high speed. Furthermore, since transmission and reception can be performed by selecting from a plurality of compression code formats depending on the communication partner device, it is possible to communicate with various types of devices. Further, since the memory can be sequentially used in half to perform image expansion processing, density restoration processing or dithering processing, and recompression processing into codes, it is possible to convert compressed code formats with a small memory capacity.

[Brief explanation of drawings]

[Figure 1] Configuration diagram of the first data conversion mechanism

[Figure 2] Configuration diagram of conventional data conversion mechanism

[Figure 3] Configuration diagram of the second data conversion mechanism

[Figure 4] Configuration diagram of the third data conversion mechanism

[Figure 5
] Configuration diagram of the fourth data conversion mechanism

[Figure 6] Block diagram of data conversion mechanism

[Figure 7] Processing flow of data conversion mechanism

[Figure 8] Data format of binary representation image

[Figure 9] Data format of multivalued image

[Fig. 10] Explanatory diagram of density restoration processing

[Figure 11] Explanatory diagram of dithering processing

[Figure 12] Configuration diagram of data amount comparison and selection mechanism

[Figure 13] Configuration diagram of the fifth data conversion mechanism

[Explanation of symbols]

101...Image filing device 102...Binary expression image expansion 103...Concentration restoration 104...Multi-value expression image compression 105...Binary representation image compression 106...Dithering 107...Multi-value expression image expansion 108...Communication interface

Claims (18)

[Claims] Claim 1: An image data conversion device in a communication adapter of an image filing device that encodes, compresses, and stores a binary representation image, and receives a compression code of the binary representation image from the image filing device. means and the code 2
data conversion means for decompressing into a value expression image, restoring the density of the binary expression image to convert it into a multi-value expression image, encoding and compressing the multi-value expression image; and means for transmitting the compressed code; means for receiving a compressed code of multi-value representation, expanding the code into a multi-value representation image, dithering the multi-value representation image to convert it into a binary representation image, encoding and compressing the binary representation image; An image data conversion device comprising: data inverse conversion means for converting data; and means for sending the compressed code to the image filing device. 2. The image forming apparatus according to claim 1, further comprising means for comparing the data amount of the compression code of the binary expression image and the compression code of the multi-value expression image, and selecting and transmitting the code with the smaller data amount.
The image data conversion device described. 3. The image data conversion apparatus according to claim 1, further comprising selection means for communicating without going through said data conversion means and said data inverse conversion means. 4. The image data according to claim 3, further comprising a table in which a compression code type of the binary expression image or the multi-value expression image that can be received by the destination is input together with the destination address or is held therein. conversion device. 5. The image data conversion apparatus according to claim 1, further comprising means for requesting retransmission of the same image as the received compression code using a compression code different from the received compression code. 6. A first storage means for storing a compression code of the binary representation image; a second storage means for storing the binary representation image obtained by decompressing the data of the first storage means; Second
a third storage means for storing the multivalue expression image obtained by restoring the density of the data in the storage means; and a fourth storage means for storing a compression code of the multivalue expression obtained by compressing the data in the third storage means. 2. A storage system for an image data conversion device according to claim 1. 7. A first storage means for storing a compression code of the multi-valued image; a second storage means for storing the multi-valued image obtained by decompressing the data in the first storage means; Second
a third storage means for storing the binary representation image obtained by dithering the data in the storage means; and a fourth storage means for storing a compression code of the binary representation obtained by compressing the data in the third storage means. 2. A storage system for an image data conversion device according to claim 1. 8. At the time of transmission, the process of expanding the compressed code to the binary representation image is stopped and density restoration processing is started, and the density restoration processing is stopped and the density of the multivalued representation image is restored. means for activating encoding; upon receiving, stopping processing for decompressing the binary representation image from the utilization device and activating dithering processing; and stopping the dithering processing;
2. The image data conversion apparatus according to claim 1, further comprising means for activating encoding of a value-expressing image, and said image data is divided and processed. 9. The image data conversion apparatus according to claim 1, wherein said image data is color image data. 10. An image data conversion device in a communication adapter of an image filing device that encodes, compresses, and stores a multivalued image, the means for receiving a compressed code of the multivalued image from the image filing device. Then, the code is expanded into a multi-value expression image, the multi-value expression image is dithered, and 2
data inverse conversion means for converting into a value representation image, encoding and compressing the binary representation image; means for transmitting the compressed code; means for receiving the compressed code of the binary representation; a data conversion means for decompressing the image into a binary expression image, restoring the density of the binary expression image to convert it into a multi-value expression image, encoding and compressing the multi-value expression image; An image data conversion device comprising means for sending data to the image filing device. 11. At least a means for storing color image data as a compressed code of a binary representation image, and a device for using the storage means via communication, wherein the color image data in the communication adapter section of the storage means is - An image data conversion method, wherein at the time of transmission, a compression code of the binary expression image is received from the storage means, the compression code of the binary expression image is expanded into a binary expression image, and the compression code of the binary expression image is expanded into a binary expression image. Restoring the density of the expanded binary expression image and converting it into a multi-value expression image, encoding and compressing the converted multi-value expression image, and transmitting the compression code of the multi-value expression image to the utilization device. At the time of reception, the compressed code of the binary representation image is received from the utilization device, the compressed code is expanded into a multivalued representation image, and the expanded multivalued representation image is dithered to create a binary representation image. 1. A color image data conversion method, comprising: converting into an expression image, encoding and compressing the converted binary expression image, and storing a compression code of the binary expression image in the storage means. 12. The color image data conversion method according to claim 11, wherein a compression code for the binary representation image and a compression code for the multivalue representation image are selected and transmitted at the time of transmission. . 13. At the time of transmission, the data amount of the compression code for the binary expression image and the compression code for the multi-value expression image are compared, and the compression code with the smaller amount of data is selected and transmitted. 12. The color image data conversion method according to claim 11. 14. At the time of transmission, the type of compression code that can be used by the utilization device is input together with the destination address to the utilization device, and the compression code to be transmitted to the utilization device is selected according to the input type. 12. The color image data conversion method according to claim 11, characterized in that the color image data conversion method is selected. 15. A plurality of the utilization devices exist, and the types of compression codes that can be used by the plurality of utilization devices are held together with the destination addresses for each of the utilization devices, and when transmitting to the utilization devices, 12. The color image data conversion method according to claim 11, wherein said compression code is selected and transmitted according to said type held. 16. When one of the two types of compression codes is received as the color image data from the utilization device at the time of reception, the same color image data is transferred to another one. 12. The color image data conversion method according to claim 11, further comprising the step of requesting retransmission using a different compression code. 17. A communication adapter for the storage means, comprising at least means for storing color image data as a compressed code of a binary or multivalued image, and a device for using the storage means via communication. 2. A color image data conversion method in a color image data conversion method, which receives a compression code of the binary expression image from the storage means at the time of transmission, and converts the compression code of the binary expression image into two.
Decompressing into a value expression image, restoring the density of the expanded binary expression image and converting it into a multivalue expression image, encoding and compressing the converted multivalue expression image, and compressing the multivalue expression image. Color image data, characterized in that the code is transmitted to the utilization device.
data conversion method. 18. A communication adapter for the storage means, comprising at least means for storing color image data as a compressed code of a binary or multivalued image, and a device for using the storage means via communication. A method for converting color image data in a color image data conversion method in which, at the time of reception, a compression code of a binary representation image is received from the utilization device, the compression code is expanded into a multivalue representation image, and the expanded multivalue representation image is A value expression image is dithered and converted into a binary expression image, the converted binary expression image is encoded and compressed, and a compression code of this binary expression image is stored in the storage means. Color image data conversion method.