JPS63182974A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To shorten the time of holding a transmission line and to improve the efficiency of the use of the line by receiving respective information of the reception code storage capacity of a receiver, its longest processing time and its transmission rate by a transmitter, operating a prediction for the adding condition of a supplementary code by using the above-said information, and thus making the code supplement finer. CONSTITUTION:The procedure signal reception circuit 11 of the transmitter receives procedure signals from the receiver. A reception signal storing circuit 12 temporarily stores these procedure signals. A receiver's function identifier circuit 13 takes out a terminal function confirmation information from among the received procedure signals, and identifies a reception code storage capacity, a longest processing time, and a transmission rate which are the function of the receiver. A code supplement instruction circuit 14 predicts the longest processing time from the receiver's function and the function of self-receiver, and predicts the amount of reception code storing in the receiver by using the transmission rate, the reception code storing capacity of the receiver, and the amount of coding of image signals for each scanning line obtained from a coding circuit 16, and calculates a code supplement condition, and outputs a transmission instruction for supplement code. The coding circuit 16 receives image signals, and encodes them into transmission codes, and at the same time adds supplementary codes under the instruction from the instruction circuit 14 in case the quantity of transmission codes is small.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is capable of changing the transmission code amount of an image signal and changing the code by the shortest processing time of the encoding circuit, decoding circuit, and recording circuit and the code transmission speed. This invention relates to a facsimile machine that inserts and transmits a supplementary code into the difference in occurrence time.

[Common technology]

In order to improve the transmission efficiency of image signals, facsimile machines perform encoding suppression by compressing and encoding, for example, consecutive white signals and consecutive black signals for each scanning line. Therefore, the amount of transmission codes generated for the image signal for each scanning line changes.

For example, in the case of a complex black and white screen in which image signals differ for each scanning point, the coding suppression rate is small and the amount of transmitted code is large.

Currently, as long as facsimile communication is carried out through the most common telephone network, the code transmission speed of the telephone line cannot be increased much. On the other hand, encoding methods that suppress the redundancy of image signals are rapidly reducing the processing time of encoders and decoders.

Therefore, on the transmitting side, since the transmission code generation speed of the image signal generated by the encoding circuit is usually faster than the transmission speed of the transmission code, if there is a storage circuit with a small capacity that temporarily stores the transmission code, it is possible to generate the transmission code. can be transmitted almost continuously. On the other hand, when the received transmission code is decoded into an image signal on the receiving side, the decoding speed is faster than the transmission speed, so the larger the amount of transmission code per fixed scan line, the more time there is for decoding. However, the recording time for each scanning line is constant, and - when the amount of transmission code for a scanning line is small, transmission codes for subsequent scanning lines arrive sequentially during this recording and exceed the capacity of the temporary storage circuit for received codes. A state in which the transmission code cannot be received occurs.

In order to avoid this, on the transmitting side, a supplementary code (so-called FILL code) is added to a certain scan line to compensate for the shortfall in the predetermined minimum guaranteed number of bits that guarantees the minimum transmission time. For example, the minimum guaranteed number of bits is determined based on the shortest processing time and the longest processing time for the image signal encoding circuit on the transmitting side and the image signal decoding circuit and recording circuit on the receiving side. be done. Normally, the recording circuit is the longest because it includes mechanical operation, and therefore the minimum guarantee period depends on the performance of the recording circuit.
) number is often set.

On the sending side, which sets the minimum guaranteed number of bits, the receiving side's function information is extracted from the function identification signal received in the receiver function confirmation procedure of CCITT Recommendation T30. For new models with superior performance, in addition to standard function information, non-standard function information is transmitted from the receiving side to the transmitting side in a non-standard function identification signal (NSF).

[Conventional technology]

In conventional facsimile machines, the sending side receives a function identification signal from the receiving side, determines the worst condition from code generation to recording to be, for example, the shortest recording time of 10 m5, and sets the effective transmission speed to, for example, 9600 bps. In this case, the minimum code amount for each scanning line, that is, the minimum guaranteed number of bits as a transmission code is (10m5×9600 bps=)96 bits, and the above-mentioned 10m5 is secured.

Therefore, the transmission code reception and storage circuit on the receiving side only needs to have a predetermined amount of code capacity for the transmission code being received.

[Problem that the invention seeks to solve]

As mentioned above, in conventional facsimile machines, the line is held up due to the worst-case processing time required to encode and record the image signal and the transmission time of the supplementary code, which is added based on the minimum guaranteed number of bits determined based on the transmission speed of the transmission code. This has the problem of deteriorating economic efficiency, especially in terms of long-distance communication fees and line usage efficiency in the communication network.

SUMMARY OF THE INVENTION An object of the present invention is to provide a facsimile machine that solves the above problems.

[Means for solving problems]

A facsimile apparatus according to the present invention includes an encoding circuit in which the amount of code of a transmission code that encodes an image signal is variable.

It has at least a transmitter that inserts a supplementary code into the difference in code generation time set by the worst processing time obtained from the shortest processing time of the decoding circuit and the recording circuit and the transmission speed of the transmission code and transmits the result.

The receiver includes terminal function confirmation information, including at least received code storage capacity information, worst-case processing time information, and transmission speed information, and sends it to the transmitter in a function confirmation procedure prior to message transmission. The transmitter calculates the amount of transmission codes to be stored in the reception code storage circuit of the destination receiver from the information (at least the reception code storage capacity Φ worst processing time and transmission speed) extracted from the confirmation information received from the receiver. The prediction is made, a necessary supplementary code is added, and the signal is sent out as a transmission code.

〔Example〕

Next, a facsimile apparatus according to the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a transmitter showing one embodiment of the present invention. The control circuits common to all 9s are omitted from illustration. The transmitter of the facsimile machine is connected to the destination receiver
The transmission line will be closed using the connection conditions of CITT Recommendation T30. In FIG. 1, the transmitter is a procedural signal receiving circuit 11.
Received signal storage circuit 12, receiver function identification circuit 13. Code replenishment instruction circuit 141 Image signal generation circuit 15. Encoding circuit 1
It has a 6° transmission code storage circuit 17 and a code transmission circuit 18. A procedure signal receiving circuit 11 receives a procedure signal from a receiver. The received signal storage circuit 12 temporarily stores the received procedure signal. The receiver function identification circuit 13 extracts terminal function confirmation information from the received procedure signal and identifies receiver functions such as received code storage capacity, worst processing time, and transmission speed. The code supplement instruction circuit 14 encodes the worst processing time and transmission speed set from the receiver function and its own transmitter function, the received code storage capacity of the receiver, and the image signal for each scanning line obtained from the encoder circuit 16. The received code storage amount of the receiver is predicted based on the amount, code compensation conditions are calculated, and a compensation code transmission instruction is output. The image signal generation circuit 15 scans the screen, digitally encodes the pigment of the pixel element for each scanning line, and outputs it as an image signal. The encoding circuit 16 receives the image signal and encodes it into a transmission code with high transmission efficiency. Since the transmission code is shortened and encoded depending on the state of continuous image signals, the amount of transmission codes for each scanning line is undefined. Furthermore, the encoding circuit 16 adds a supplementary code to a small amount of transmitted codes according to instructions from the code supplementation instruction circuit 14. The transmission code storage circuit 17 temporarily stores the output of the encoding circuit 16, and the code transmission circuit 18 sends out the transmission code.

Next, the terminal function confirmation information identified by the receiver function identification (b) path 13 will be explained. Terminal function confirmation information is CCIT
T Recommendation T3 Recommendation 30 standard functions include digital identification signals (
A non-standard function signal (hereinafter DIS signal) and a non-standard function signal K (hereinafter NSF signal) are transmitted from the receiver to the transmitter. In this embodiment, the received code storage capacity information of the receiver is
Include in F signal. The worst-case processing time and transmission rate are also included in the NSF signal if they are non-standard values. The transmission rate to be implemented is set taking into consideration the transmitter functionality of the transmitter itself.

The code compensation condition is that a compensation code is added to the received code accumulation amount of the receiver [13°, the minimum transmission time MT of the receiver, the set transmission rate υ, and the minimum transmission code amount CMIN for each scanning line that can occur υ. As an example of the threshold value, the following arithmetic expression (1) can be set.

L≦B-(MT11υ-CMIN)・・・・・・・・・
・(1) On the other hand, the received code accumulation amount Rn-1 of the receiver for the transmission code of the previous scanning line, and the worst processing time T of the receiver
From MIN and the code amount C of the scanning line, the storage amount an of the received code storage circuit is determined by the following equation.

an=Rn-1+ (TMIN IIυ-〇)...
(2) Therefore, the code supplement instruction circuit 14 performs the above (
By calculating the equation 2), the transmission code amount C for each scanning line is calculated as TMIN 'υ〉C and L(an and @(TMzN
- υ-C) Add as many complementary codes as transmission codes.

In the above embodiment, only the transmission code amount for the previous scanning line is the subject of calculation, but it is more effective to use an arithmetic expression in which the condition (TMIN·υ>C) is continuous. Moreover, the calculation formula (1) for the threshold value can be set more precisely by taking into consideration the margin of the received code storage amount B of the receiver. Furthermore, the calculation formula for the storage amount an of the reception code storage circuit (
Of course, even in 2), more detailed settings can be made from the value of the received code accumulation 1tRn-1 for the transmission code of the previous scanning line, the value of the worst processing time TMIN of the receiver, etc.

〔Effect of the invention〕

According to the facsimile apparatus of the present invention, the transmitter receives information on the received code storage capacity, worst-case processing time, and transmission speed of the receiver as function confirmation information from the receiver, and uses these information to determine supplementary code addition conditions. Since it is configured to perform predictive calculations, fine-grained code compensation can reduce line holding on the transmission line, improve line usage efficiency, and improve the receiver's progress with new technology. This has the operational and economical effect of being able to respond without any changes when the situation arises.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a transmitter showing an embodiment of the facsimile apparatus of the present invention.

Claims (1)

[Claims] The code amount of the transmission code that encodes the image signal for each scanning line is variable, and the maximum processing time of the processing system for each scanning line obtained from the shortest processing time of each of encoding processing, decoding processing, and recording processing is the worst case. In a facsimile machine that inserts a supplementary code into the difference in code generation time set by the worst processing time and the transmission speed of the transmission code and transmits the data, the terminal receives the data from the destination receiver in the function check procedure. The information on at least the received code storage capacity, the worst processing time, and the transmission speed included in the function confirmation information is extracted, and the amount of transmitted codes stored in the received code storage circuit of the destination receiver is calculated and predicted. A facsimile device comprising a transmitter that adds a supplementary code and sends it out as a transmission code.