JPS6065662A - Facsimile communication system - Google Patents

Abstract

PURPOSE:To improve the efficiency of picture information transmission and to attain appropriate scanning by switching automatically the line density in subscanning direction to a suitable density in response to picture information in the process of transmission of picture information for one page's share. CONSTITUTION:A discrimination section 30 discriminates that picture information is coarse when a prescribed number or over of white signals are consecutive in the picture information for one main scanning line's share of the original read at the transmission side, and the information is fine in other cases. The original of the next main scanning line is read by the scanning line density in the subscanning direction corresponding to the discrimination. Moreover, the discrimination information (h) is added at each picture information for one main scanning line's share and the result is transmitted to a reception side 2. The picture information for the next main scanning line's share is decoded by a control section 100 at the reception side 2, the discrimination information (h) is added to a recoder 90, where the picture recording mode is decided and the signal is recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a facsimile communication system, and in particular, the scanning line density in the sub-scanning direction is automatically switched for each main-scanning direction according to the image content. Regarding facsimile communication methods.

[Prior art]

In general, facsimile communication systems have two scanning line densities in the sub-scanning direction: standard image quality (for example, 3.85 lines/dragon) and high image quality (for example, 7.7 lines/dragon). Line density switching is performed based on operator specifications. In addition, conventionally, the scanning line density could be switched in units of one page of the original, so even if coarse parts and dense parts of the recorded image coexist within one page of the original, they can all be scanned in the same way. Scanning could only be done at linear density. For this reason, coarse portions of the recorded image are scanned with high image quality, and dense portions are scanned with standard image quality. In such a case, it cannot be said that efficient transmission and appropriate scanning (reading and recording) are performed.

[Purpose of the invention]

This invention was made in view of the above circumstances, j) 1.
A facsimile machine that can perform appropriate scanning and efficiently transmit image information by automatically switching the line density in the sub-scanning direction to an appropriate one according to the image information in the process of transmitting image information for one page. The purpose is to provide a communication method.

[Structure of the invention]

Therefore, in this invention, if a predetermined number or more of consecutive white signals are present in the image information for a lifetime scanning line of the document read by the sending side, the image information for the main scanning line is coarse; otherwise, it is dense. The next main scanning green document is read at the scanning line density in the sub-scanning direction corresponding to the discrimination, and the discrimination information is added to each image information of the main scanning line and transmitted to the receiving side. As a result, on the receiving side, image information for the next main scanning line is recorded at the scanning line density corresponding to the discrimination information.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The facsimile communication system according to the present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

The figure shows an example of a configuration for implementing the invention.

In the figure, a transmitting station 1 and a receiving station 2 are connected via a communication line 5.

In the transmitting station 1, the reading device 10 includes, for example, an image sensor and a sensor driver that drives and controls the image sensor, and reads an image of a transmitted document. Here, the reading device 10 is in high image quality mode (7.0 in the sub-scanning direction).
Document images can be read at two scanning line densities: 7 lines/un) and standard mode (3.85 lines/mm in the sub-scanning direction). Normally, the above standard mode is read in the above high quality mode. The image information obtained by calculating the logical sum of each dot for two main scanning lines constitutes image information for one main scanning line. The image information of the document read by the reading device 10 is sequentially stored in the memory 20 and the determination unit 3 for each main scanning line.
It is input to 0. The memory 20 is a line buffer that can store image information for at least one main scanning line, and outputs the stored image information to the encoding section 40. The determination unit 30 determines whether the input image information is coarse or fine; if the image information for each main scanning line contains a predetermined number or more of consecutive white signals, it is coarse; otherwise, it is coarse. The discrimination information is read by the reading device R10 and the encoding unit 40.
Send one. The reading device 10 determines the image reading mode for the next main scan based on the discrimination information.

In other words, if the image information for the main scanning line is coarse, the normal main scanning line is scanned in the standard mode, and if the image information for the main scanning line is dense, the normal main scanning line is scanned in the standard mode. Read and scan lines in high-quality mode. Next, the encoding unit 40 encodes the image information input from the memory 20 using an appropriate redundancy reduction encoding method, for example, a one-dimensional band compression processing method such as the modified Huffman method. During this encoding, the discrimination information inputted from the determination section 30 is added to the encoded information for each main scanning line. As the encoded information, any method may be used as long as it can determine whether the image information for each main scanning line is coarse or dense. For example, there is a method of adding one bit of information as long as it does not interfere with decoding of a predetermined encoding format, and a method of determining density based on the presence or absence of a fill bit. The encoded information encoded as described above by the encoder 40 is once stored in the memory 50 and then transmitted onto the communication line 5 via the network control/modulation/demodulator 60.

In addition to the illustrated configuration, the transmitting station 1 also includes a control section for controlling communications and managing operation sequences, but these are not shown here.

Next, the receiving station 2, like a general facsimile machine, has a network control/modulation/demodulation section 70, a decoding section 80, and a main scanning line segment that can be printed simultaneously and has two scanning line densities: a high-quality mode and a standard mode. a recording device 90 capable of performing recording operations;
The configuration includes a control section 100 that performs various controls on the above-mentioned components, and here, in particular, the following operations are performed. That is, the control unit 100 decodes the encoded information for each line containing the above-mentioned discrimination information received from the transmitting station 1 for each main scanning line, and adds the discrimination information to the recording device 90. The recording device 90 determines the image recording mode for the normal main scanning line based on the discrimination information. If the image information (encoded information) for the main scanning line is coarse, the next main scanning line is recorded in standard mode, and if the image information for the main scanning line is dense, the next main scanning line is recorded. The main scanning line is scanned for recording in high image quality mode.

In this manner, the receiving station 2 records image information at the same scanning line density as the recording scanning line density of the transmitting station 1 based on the discrimination information representing the density of the image information.

Note that in the above embodiment, the one-dimensional band compression method is used in the encoding unit 4.
However, by appropriately changing the configuration of the memory 20 and the like, it is possible to adopt a two-dimensional encoding method such as mode or f-fied read method in the encoding section 40.

〔Effect of the invention〕

As explained above, according to the facsimile communication method according to the present invention, since the scanning line density in the sub-scanning direction can be automatically switched for each scanning line depending on the image content, coarse parts and Even in an image containing a mixture of dense parts, efficient image information transmission and appropriate reading and recording scanning can be realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a configuration for implementing a facsimile communication system according to the present invention. 1 Transmitting station, 2... Receiving station, 10... Reading device, 20
. . . Memory, 30 . . . Determination unit, 40 . . Encoding unit, 5
0.Memory, 60, 70 Network control/modulation/demodulation section, 80.
...Decoding section, 90... Recording device, 100... Control section.

Claims (1)

[Claims] In a facsimile communication system that has two different scanning line densities in the sub-scanning direction and reads and records a document at one of the scanning line densities mentioned above, white is added to the image information for the entire scanning line of the document read by the sending side. If the signal continues for a predetermined number or more, the original manuscript is read, and the above-mentioned discrimination information is added to each image information of the main scanning line and transmitted to the receiving side, so that the receiving side can perform the next main scanning synthesis. A facsimile communication system, characterized in that image information is recorded at the scanning line density corresponding to the discrimination information.