Moving-picture signal coding and/or decoding system resistant to transmission error

Abstract

An input image signal is coded by an encoder to be outputted as a basic code string, and the basic code string is delayed by a code-string delay circuit for a predetermined period of time to be outputted as an additional code string. The basic code string is synthesized with the additional code string by a code-string synthesizer to be outputted as an output code string. Thus, there is provided an image data coding system which can quickly restore data even if the data is lost due to error and in which the increased code amount is less than the cycle refresh and the error correction.

Description

[0001]More than one reissue application has been filed for the reissue of U.S. Pat. No. 6,701,018. The currently pending reissue applications are applications Ser. Nos. 11 / 366,010; 12 / 232,511; 12 / 654,141; 12 / 762,604; 12 / 762,642; 12 / 762,669; 12 / 232,509; 12 / 654,140; 12 / 763,064; 12 / 763,052; 12 / 763,036; 12 / 762,722; 12 / 272,510; 12 / 591,980; 12 / 762,864; 12 / 762,834; 12 / 762,793; 12 / 762,756; 12 / 762,686; 12 / 272,508; 12 / 591,981; 12 / 762,795; 12 / 762,972; 12 / 762,983; 12 / 762,745; 12 / 762,998; and 12 / 762,935.[0002]This is a divisional reissue application of U.S. reissue application Ser. No. 12 / 591,980, filed Dec. 7, 2009, which is a divisional reissue application of U.S. reissue application Ser. No. 12 / 232,510, filed Sep. 18, 2008, which is a divisional reissue application of U.S. reissue application Ser. No. 11 / 366,010, filed Mar. 2, 2006, now abandoned, which is a reissue application of U.S. Pat. No. 6,701,018, which is a divisional of application Ser. No. 09 / 471,415 filed Dec. 23, 1999, now U.S. P...

AI Technical Summary

Benefits of technology

[0016]It is therefore an object of the present invention to provide a moving-picture coding and / or decoding system which can quickly restore if data is lost due to error and in which the increased code amount is less than those of the refresh and the error correction.

Problems solved by technology

However, in such a conventional moving-picture coding and / or decoding system, there are the following problems.

In a channel in which an error may be mixed, such as a radio channel, when only the aforementioned coding is carried out, the quality of the decoded image is remarkably deteriorated if an error occurs.

In particular, when there is an error in a signal such as a synchronizing signal, a mode data and a motion vector, the picture quality is remarkably deteriorated.

However, since only the interframe difference is coded in the motion-compensated adaptive prediction coding, when an error occurs, the frame is not only incorrect, but an incorrect image is also stored in a frame memory, so that a predicted image is prepared using the incorrect image and a residual error is added thereto.

For that reason, even if the subsequent frame is correctly decoded, it is not possible to obtain a correctly decoded image in the subsequent frame, except that when the data is transmitted in a mode (INTRA mode) wherein the coding is performed in only the frame without using the interframe difference or when the influence of the error is gradually attenuated to return to the original state.

Thereafter, since the residual error is added to the incorrect image, the error is not basically erased, so that it is not possible to reproduce a correctly decoded image.

In this case, when the coding is performed in the INTRA mode, the code amount is increased to remarkably deteriorate the picture quality when no error occurs.

However, although the cyclic refresh is able to resstring the increase of the code string, there is a problem in that it takes a long time until the normal state is restored.

However, if errors of hundreds bits occur at a burst and continuously, it is difficult to correct such errors.

Even if it is possible to correct such errors, a very long redundancy is required.

As mentioned above, in en image coding, particularly in a moving-picture coding, the loss of data due to error greatly deteriorates the picture quality.

In addition, in the conventional methods such as the cyclic refresh for restoring the lost data due to error, there are problems in that it takes a long time until it is restored considering the coding efficiency, and that the attempt to decrease the time required to restore the lost data increases the code amount to lower the efficiency.

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