JPH03253175A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To reproduce an intermediate tone picture with high quality by using an intermediate tone picture as multi-value picture information, applying compression encoding transmission, reproducing the multi-value picture signal at a receiver side and binarizing the signal as a pseudo intermediate tone. CONSTITUTION:A picture signal read by an original read section 1 is A/D- converted for each picture element, transferred to an encoding section 2 as a multi-value signal, compressed-coded and sent via a transmission section 3. The protocol is analyzed at a reception section 4 at a receiver side and only the coded picture information is decoded by a decoding section 5 and the reproduced multi-value picture signal is converted into a binary picture signal at a pseudo intermediate tone generating section 6. In this case, since the pseudo intermediate tone processing is implemented at the receiver side, a binarization parameter is optimizingly selected in response to the recording characteristic. Thus, the intermediate tone picture with high quality is reproduced when the signal is recorded by a recording section 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a facsimile device, and more particularly to a facsimile device that has a binary recording method and can reproduce halftone images.

[Conventional technology]

Conventionally, in a facsimile apparatus having a recording section using a binary recording method, when reproducing a halftone image, the sending side binarizes it to generate a pseudo halftone image and transmits it.

[Problem to be solved by the invention]

In the above-mentioned conventional facsimile machine, since the sending side performs binarization to generate a pseudo-halftone image, it is not possible to perform binarization according to the recording characteristics of the receiver, and a receiver of the same model cannot produce a high-quality halftone image. Even if the image is reproduced, it has the disadvantage that a high-quality image cannot be reproduced if it is transmitted to a receiver having a different recording method.

[Means to solve the problem]

A facsimile device of the present invention includes a document reading section that reads a document and outputs a multilevel image signal, an encoding section that encodes the multilevel image signal from the document reading section, and a code output from the encoding section. a transmitter that transmits encoded image information to a transmission path; a receiver that receives encoded image information from the transmission path; a decoder that receives encoded image information from the receiver and decodes it; The image forming apparatus includes a pseudo halftone image signal generation section that binarizes the multilevel image signal, and a recording section that records the pseudo halftone image signal according to the binary image signal from the generation section.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

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

In FIG. 1, numeral 1 is a document reading unit that scans a document, converts analog signals corresponding to the density of the document image into pixels as pixels, and outputs a digital multi-value image signal; 2 is a device that outputs a digital multi-value image signal; An encoding unit that performs compression encoding; 3 a transmitting unit that sends encoded image information to a transmission path according to a predetermined protocol; 4 a receiving unit that receives image information from the transmission path; 5 a receiving unit 4; 6 is a pseudo intermediate that converts the reproduced digital multilevel image signal into a pseudo halftone binary image signal. The tone generation section 7 is a recording section that records an image in binary form according to the binary image signal from the pseudo halftone generation section.

The image signal read by the document reading section 1 is A/D converted for each pixel, and then transferred to the encoding section as a multivalued image signal.

The encoding unit 2 uses DCT (Discret
Various encoding methods are known, including the Co-5ine Transform) method, and any encoding method may be used as long as it is consistent with the encoding unit 5. The encoded image information is transmitted to the receiver via the transmitter 3.

On the receiving side, the receiving section 4 analyzes the protocol and transfers only encoded image information to the encoding section 5. The multivalued image signal decoded and reproduced by the encoding unit 5 is converted into a binary image signal by the pseudo halftone generation unit 6. There are various pseudo-halftone methods known for converting a multilevel image signal into a binary image signal without losing the intermediate tones, such as the systematic dither method, random dither method, and error diffusion method. What is important here is that pseudo-halftoning is performed on the receiving side, so the parameters for 2M conversion can be optimally selected according to the recording method and recording characteristics of the receiver. It is possible to adjust the generation of pseudo halftones so that a high quality halftone image is reproduced when recorded by the recording section. Pseudo halftone generation section 6
The binary image signal generated in is recorded as an image in the recording section 7 and reproduced.

〔Effect of the invention〕

As explained above, according to the present invention, a halftone image is compressed and encoded as multilevel image information and transmitted, and the receiving side reproduces the multilevel image signal and then binarizes it as pseudo halftone, thereby recording. It is possible to generate a pseudo halftone image signal according to the characteristics of the area, and therefore, there is an effect that a high quality halftone image can always be reproduced.

signal unit, 4...receiving unit, 5...decoding unit, 6...pseudo halftone generation unit, 7...recording unit.

Claims (1)

[Claims] A document reading section that reads a document and outputs a multilevel image signal, an encoding section that encodes the multilevel image signal from the document reading section, and encoded image information output from the encoding section is sent to a transmission path. A transmitting section that transmits data, a receiving section that receives coded image information from the transmission path, a decoding section that receives and decodes the coded image information from the receiving section, and a multilevel image signal from the decoding section that converts the multilevel image signal into two. A facsimile apparatus comprising: a pseudo-halftone image signal generating section that converts into values; and a recording section that records in accordance with the binary image signal from the pseudo-halftone image signal generating section.