DATA DECOMPRESSING DEVICE AND NON-TRANSITORY COMPUTER READABLE MEDIUM

摘要

A data decompressing device includes an effective code length detector and a determining unit. The detector detects an effective code length of an initial portion of compressed image data to be decompressed, and supplies the detected effective code length to a decompressing unit to decompress data having the effective code length from a head of the image data. The determining unit determines whether or not the initial portion of the image data corresponds to a specific pattern in which a block end code follows a code representing a specific DC difference value, and if having determined that the initial portion of the image data corresponds to the specific pattern, notifies the decompressing unit of the detection of the specific pattern without waiting for the detection of the effective code length, to allow the decompressing unit to output a predetermined decompression result corresponding to the specific DC difference value.

主权项

1. A data decompressing device comprising:
an effective code length detector that detects an effective code length of an initial portion of compressed image data to be decompressed, and supplies the detected effective code length to a decompressing unit to allow the decompressing unit to decompress data having the effective code length from a head of the compressed image data; and a determining unit that determines whether or not the initial portion of the compressed image data to be decompressed corresponds to a specific pattern in which a code representing a specific direct-current difference value is followed by a block end code, and if having determined that the initial portion of the compressed image data to be decompressed corresponds to the specific pattern, notifies the decompressing unit of the detection of the specific pattern without waiting for the detection of the effective code length by the effective code length detector, to allow the decompressing unit to output a predetermined decompression result corresponding to the specific direct-current difference value.