JPS61129976A - Picture data compression/reproducing device - Google Patents

Abstract

PURPOSE:To speed up processing as a result of eliminating wasteful time during compressing and reproducing process by installing an FIFO memory between the run length counter means and the compressed data transmitting/receiving means. CONSTITUTION:The variation point detector 1 shall continue to send out picture data request A to the picture source until picture data B changes. The FIFO-IN controller 6 by the change in signal from the detector 1 shall store in the FIFO memory 4, the code E comprising run length value D of the run length counter 2 converted to MH code by the code generator 3, and resets the counter 2. The compressed data sending part 5, by control of the FIFO-OUT controller 7, shall transmit MH code F input from the FIFO4 after converting to serial data. Then, regardless of the operation of the compressed data sending part, the run length counter 2 shall be able to continue counting up to the capacity of the FIFO, thereby eliminating wasteful time, speeding up processing.

Description

TECHNICAL FIELD The present invention relates to a data compression/reproduction device in an image data processing system, and more particularly to a compression/reproduction device that can improve the processing speed of a compression/reproduction process.

Prior Art Conventionally, in an image data compression/reproduction device, during compression,
It is necessary to detect the change point in the image data and stop the process of detecting the next change point until the code has been generated. Also, during playback, it is necessary to detect the valid compressed data and stop the process of detecting the next change point.
It is necessary to stop the process of detecting the next valid compressed data until the image data has been generated.

FIG. 2 shows a conventional M H (Modified Huf).
It is a block diagram of a compression circuit using fman) code,
FIG. 3 is an operation time chart of FIG. 2.

As shown in FIG. 2, the conventional MH compression circuit includes a change point detection section 1, a run length counter 2, a code generation section 3, and a compressed data transmission section 5.

First, the changing point detection unit 1 issues an image data request to the image data source, and continues issuing the request until a changing point is detected. When a change point is detected, the image data request signal is stopped. When a change point is detected, the shift signal is checked to confirm that the compression code transmission for the previous run length has been completed, and then the MH for the current run length is
The code is loaded into the compressed data sending section 5. At the same time, a reset signal for resetting the run length counter 2 is issued.

The run length counter 2 is a counter for counting the run length up to the change point, and sends the counted run length value to the code generation section 3. The code generator 3 is usually composed of a ROM, and inputs the run length to the address.

Outputs the MH code according to the run length.

The compressed data sending unit (shift register) 5 loads the MH code input as a parallel signal when a change point occurs, converts the valid part of the MH code into serial data, and sends the serial data.

In FIG. 3, when image data and data Enable are input in synchronization with the clock CLK, the change point detection unit 1 detects the first white signal, issues the next image data request, and then outputs the first black signal. At the time of signal detection, a set signal is sent to the run length counter 2 and the compressed data sending section 5 to reset the counter 2.

Start sending the MH code. After loading the MH code into the compressed data sending unit 5, it is shifted and the compressed data D1
~ Send D4. After sending out the data D1 to D4, a shift end signal is issued to enable setting from the change point detection section 1. On the other hand, the run length counter 2 needs to count the next black signal and send the run length value RL2 to the code generator 3.

However, the first run length value RLI (white 2 bits)
The processing of the primary run length value RL2 must be stopped while the data is being encoded into MH code and the data is being sent from the compressed data sending unit 5 (see period 2 in FIG. 3). When the shift end signal is sent from the compressed data sending unit 5 to the changing point detecting unit 1, a set signal is output from the changing point detecting unit 1, which causes the run length counter 2 to continue counting, and the next An image data request signal is issued. In this way, conventionally, counting is stopped while compressed data is being transmitted, which results in wasted time during the compression and reproduction processing process, making it impossible to perform efficient processing.

OBJECTS It is an object of the present invention to provide an image data compression/reproduction device that can solve the above-mentioned conventional problems, eliminate wasted time during compression/reproduction processing, and speed up the processing process.

Configuration To achieve the above object, the image data compression/reproduction apparatus of the present invention includes a counter means for counting the run length of image data and a compressed data transmitting/receiving apparatus for transmitting and receiving a compressed code corresponding to the count value counted by the counter means. In the image data compression/reproducing apparatus equipped with a means for compressing and reproducing image data, an FI
A feature is that a FO (first-in, first-out) memory is provided and advance processing is performed for the capacity stored in the FIFO.

Hereinafter, the configuration of the present invention will be explained using examples.

FIG. 1 is a block diagram of an image data compression circuit showing one embodiment of the present invention.

2 is a change point detection section, 2 is a run length counter, 3 is a code generation section, and 5 is a compressed data transmission section.

These have the same configuration as before, but in addition to this, there is a new FI
FO4, FI'FOIN control section 6, and FI
A FOOUT control section 7 is provided.

In this way, in FIG. 1, between the run length counter 2 and the compressed data sending section 5, specifically between the code generating section 3 and the compressed data sending section 5.

A FIFO 4 is inserted to logically separate the compressed data sending section 5. As a result, even if the compressed data sending unit 5 is in operation, the count of the run length counter 2 is
Preliminary checking can be performed in proportion to the capacity of FIFO 4, improving processing speed.

The change point detection unit 1 converts the set signal obtained by detecting the change point into an FI
FOIN control section 6, compressed data sending section 5
The shift end signal by sending compressed data is sent to FIFO○U.
The signal is sent to the T control section 7. The run length counter 2 sends the counted value to the code generator 3, and
After generating the H code, this code is input to the FIFO 4 under the control of the FIFOIN control section 6.

On the other hand, the MH code input from the FIFO 04 to the compressed data sending section 5 under the control of the FIFOOUT control section 7 is sent out after being converted into serial data.

In this way, the run-length counter 2 and the compressed data sending section 5 are completely separated, and the run-length counter 2 can continue counting by the length of data stored in the FIFO 4. Although only compression processing has been described in the embodiment, it is also applicable to reproduction processing in the same way.

Effects As explained above, according to the present invention, since the FIFO is inserted between the run-length counter and the compressed data sending section, advance checks (counter operations of the run-length counter) are performed in accordance with the capacity of the FIFO. It is possible,
Since there is no need to interrupt the processing, compression and playback processing can be speeded up.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an image data compression device showing an embodiment of the present invention, FIG. 2 is a block diagram of a conventional data compression device, and FIG. 3 is an operation time chart of FIG. 2. 1: Change point detection unit, 2: Run length counter, 3: Code generation unit, 4: FIFO, 5: Compressed data transmission unit, 6
:FIFOIN control section. 7: FIFO○UT control section. Patent applicant: Ricoh Co., Ltd.

Claims (1)

[Claims] An image data compression/reproduction device comprising a counter means for counting the run length of image data and a compressed data transmitting/receiving means for transmitting/receiving a compressed code corresponding to the count value counted by the counter means, the counter means and the compressed data transmitting/receiving means. A FIFO (first-in, first-out) memory is provided between the
An image data compression/reproduction device characterized in that advance processing is performed for the amount stored in O.