Browse Prior Art Database

Parallel Compression/Decompression Method for Joint Photographic Experts Group

IP.com Disclosure Number: IPCOM000114252D
Original Publication Date: 1994-Nov-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 2 page(s) / 79K

Publishing Venue

IBM

Related People

Watanabe, Y: AUTHOR

Abstract

Disclosed here is a parallel processing method for Joint Photographic Experts Group (JPEG) Image Compression/Decompression, which is beneficial when using several compression/decompression processing units.

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Parallel Compression/Decompression Method for Joint Photographic
Experts Group

      Disclosed here is a parallel processing method for Joint
Photographic Experts Group (JPEG) Image Compression/Decompression,
which is beneficial when using several compression/decompression
processing units.

      JPEG is the standard about still image
compression/decompression algorithms and there are many H/Ws or S/Ws
to process those algorithms.  Sometimes, there are several JPEG
compression/decompression processors available in one system.  For
example, if the system has L CPUs with JPEG S/W and M optional H/Ws
for JPEG, there are N(=L+M) processing units for image
compression/decompression.

      The input original image will be splitted into N or more
blocks.  The sizes of each blocks can be same or different according
to the performance of each JPEG unit.  Or, the number of the blocks
can be more than N, so that each block can be supplied to an idle
unit.

      Compressing method is shown in Fig. 1.  The original image is
splitted into N-blocks and splitted blocks are compressed and
gathered into 1 compressed image.  Each compressed block begins with
RST (Restart Interval Marker Code) defined in JPEG.  This marker code
indicates that the following compressed data can be individually
decompressed without using the data of previous block.  However,
after compression, the size of the each block is not fixed length, so
there is no way to know where are all the R...