JPH0278373A - Picture data transmission equipment - Google Patents

Abstract

PURPOSE:To shorten transmission time by sending a picture data of a part in which a picture exists and compressing the picture. CONSTITUTION:A picture 12 of a document 10 is read by an image input circuit 21, converted into an electric signal by a photoelectric conversion circuit 22 and stored in a picture memory 25. An X-Y position detection storage circuit 26 discriminates an existing position of a picture area 11 in which the picture exists actually in the case of storage. The picture information only in the picture area 11 stored in the picture memory 25 is compressed by a picture data compression circuit 27 and stored in a compression data memory 28. The stored picture data is sent to a work station 50 via a data transmission/deception circuit 29 through an interface cable 40.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an image data transmission apparatus, and more particularly to an image data transmission apparatus that reduces image transmission time.

"Prior art" For example, in devices that have the function of transmitting text and images, such as workstations and facsimile machines, it would take a long time to transmit the image information on a document read by a reading device. Become something. Therefore, redundant parts in the image information can be removed using MH (Modif).
ied Huffman) method and MR (Modify) method.
Image information was transmitted by compressing it using a data compression method such as ed Read) method. These methods not only transmit compressed data, but also transmit ``data (code) indicating that no image exists'' for areas where no image exists.

However, even if the data is compressed as described above, the amount of image information is generally enormous, so it still takes a long time to transmit it.

On the other hand, as is well known, a workstation has at least a word processing function, a communication function, and a database function.
(Local Area Netv+ork). Recently, the processing speed of the terminal device itself of such a workstation has increased to 10 Mbit for communication processing, for example.
/sec to 100 Mbit/s
It is improving as shown in e c.

"Problem to be Solved by the Invention" By the way, a wired line such as a LAN is generally used to transmit image information at a workstation.

In this case, if we try to shorten the transmission time, it is not enough to improve the processing speed of the terminal device itself as described above.
It is also necessary to increase the transmission speed of wired lines. However, increasing the transmission speed of existing wired lines costs a huge amount of money and is not easy to implement.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide an image data transmission device that can shorten transmission time even when conventional wired lines are used as is. .

In the present invention, a reading means for reading image data on a document, an image start position detection means for detecting an image start position where image data exists in an output signal of the reading means, an image start position detection means for detecting an image start position where the image data in the output signal exists; a compression means for compressing the image data in the part where the image data exists in the output signal;
When transmitting the image data, the image data is compressed by the compression means, and the image start position information detected by the image start position detection means is added to the image start position information detected by the image start position detection means. This is installed in the processing equipment.

In this way, nothing is transmitted for the part where the image does not exist, so it does not take much time to transmit, and only the image data for the part where the image exists is transmitted, and the image data to be transmitted is also compressed. Therefore, it becomes possible to significantly reduce transmission time.

〔Example〕

Next, the present invention will be explained based on illustrated embodiments. .

FIG. 1 is a block diagram when the image data transmission apparatus of the present invention is applied to a workstation.

As shown in the figure, in this image data transmission device, image data on a document 10 is read by an image input device 2o having an image input circuit, the read image data is transmitted to a workstation 5o via an interface cable 40, and is displayed on a display. The system is designed to display information such as the following.

As shown in FIGS. 1 and 2, an image area 11 on the surface of a rectangular document 1o made of a suitable paper, etc.
, an image 12 consisting of characters, figures, etc. is drawn.

The image area 11 has a vertically long rectangular shape, and the coordinates of the upper left corner are P (X,, Y, ''), and those of the lower right corner are P (X2. Y2).

The image 12 of the document IO is read by an image input circuit 21 consisting of a light source, an image sensor, etc., and the output optical signal is converted into an electrical signal by a photoelectric conversion circuit 22. Control of the above-mentioned optical signal and scanning of the image input circuit 21 is performed by a video control circuit 23.

The image information output from the video control circuit 23 is transferred to a DMA (Direct) that directly transfers the image information to the memory.
! The image data is stored in the image memory 25 under the transfer control of the DMA:I control circuit 24 that performs the following. During this storage, the X-Y position detection and storage circuit 26 determines the position of the image area 11 where the image actually exists as coordinates.

The image information of only the image area 11 in which the image stored in the star image memory 25 exists is compressed by an appropriate method in the image data compression circuit 27 and stored in the compressed data memory 28. The image data thus stored is transmitted to the workstation 5o via the data transmitting/receiving circuit 29 and the interface cable 4°.

The control of the entire apparatus as described above is performed by the CPU 30.

The compressed image information transmitted from the data transmitting/receiving circuit 29 of the image human power device 20 is transmitted through the interface cable 4.
The data is received by the data transmitting/receiving circuit 51 on the workstation 50 side via 0, and the output compressed data is decompressed by the data decompressing circuit 52. This expanded output is stored as image information in the memory circuit 53, and the image processing circuit 5
4 performs various image processing such as expansion, reduction, and rotation.

The image information processed in this manner is displayed on the display 56 after being processed by the display control circuit 55, or output as a hard copy to the printer 58 under the control of the printer control circuit 57. The overall control of the workstation 50 as described above is executed by the CPtJ 59.

Next, the operation of the image data transmission apparatus configured as described above will be explained along the flowcharts shown in FIG. 3 (transmission side) and FIG. 5 (reception side).

As shown in FIG. 3, the image information on Dokinimen) 10 is read by the image input circuit 21 (step ■).
The image information is photoelectrically converted by the photoelectric conversion circuit 22 (step 2), and stored in the image memory 25 via the video control circuit 23 under the control of the DMA control circuit 24 (step 2).

When storing this image information in the image memory 25, as shown in FIG.
Position information P (XI, Yl
) and the position information P(X2.Y2) of the lower right corner, x-Y
Detected and stored in the position detection storage circuit 26 (step ■
). This is because by specifying these P(X,, Yl) and P(x2.y2), it is possible to determine the area where the image exists.

In order to detect this position information, by scanning in the X direction, the minimum value of the coordinates of the changing point of the image (where the image starts) is set to X, and the maximum value is set to x2, and similarly by scanning in the Y direction, the coordinates are Let the minimum value be Y, and the maximum value be Y2.

In this way, the change point of the image P (X,,Y, ),
The image area 11 surrounded by ■).

Then, the X-
The Y coordinate information and the compressed data stored in the compressed data memory 28 are combined into a format for transmission as shown in FIG. The data is transmitted to the data transmitting/receiving circuit 51 on the 50 side (step ■). That is, according to this transmission format,
Of the document 10 shown in FIG. 2, data (codes) in a portion where no image exists (in the figure, all white portions excluding the image area 11) are not transmitted at all. Therefore, the amount of transmission can be reduced, and the transmission time can be reduced.

Next, the operation on the receiving side will be explained with reference to the flowchart shown in FIG.

The transmitted data is received by the data transmitting/receiving circuit 51 (
The image is divided into image position information and compressed data (step ■). Of these, the compressed data is expanded by the data decompression circuit 52 into bitmap image information in which image information corresponds to each memory element on a 1:1 basis (step ■).
, are stored in the data memory circuit 53.

Next, the image processing circuit 54 performs image processing such as composition, expansion, reduction, rotation, etc. on the position information and image information (step (2)). Then, the data is sent to the display 56 by the display control circuit 55 for display, or sent to the printer 58 by the print control circuit 57 to be printed out (step 2).

In this embodiment, a case has been described in which image data read by the image processing device 20 is transmitted to the workstation 50, but the present invention can also be applied to facsimile machines, workstations, etc. that use general wired lines. Of course you can.

"Effects of the Invention" As explained above, according to the present invention, the positional information of the part of the document where the image exists is transmitted without transmitting anything about the part where the image does not exist, and the data of that part is transmitted. Since the amount of image information to be transmitted is omitted by compression, it is possible to shorten the transmission time even if the conventional wired line is used as is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an image data transmission device showing an embodiment of the present invention, and FIG. 2 is a conceptual diagram showing an area where images exist on a document applied to the image data transmission device of the present invention.
FIG. 3 is a flowchart showing the operation on the transmitting side of the image data transmission device of the present invention, FIG. 4 is a diagram showing the data transmission format used in the image data transmission device of the invention, and FIG.
The figure is a flowchart showing the operation of the receiving side of the image data transmission apparatus of the present invention. 10...Document, 11...Image area, 12...Image, 20...Image human power device, 21...Image input circuit ( reading means), 26... X-Y position detection storage circuit (image start position/start position detection means), 27... image data compression means, 29... data transmission/reception Circuit (transmission means), 40...Interface cable, 50...Workstation. Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Umeo Yamauchi Figure 2 S λ! ,)*! Saw [Data Figure 3 Figure 5

Claims (1)

[Scope of Claims] Reading means for reading image data on a document such as a document; Image start position detection means for detecting an image start position where image data exists in an output signal of the reading means; image end position detection means for detecting an image end position where image data exists; compression means for compressing image data in a portion of the output signal where image data exists; Image data characterized by comprising a transmitting means for transmitting, together with the image data, image start position information detected by the image start position detection means and image end position information detected by the image end position detection means. Transmission device.