Decoding circuit, decoding method, encoding circuit, and encoding method

A decoding circuit that decodes encoded data generated by image compression encoding for transforming image data into plural coefficient data in units of a block of a predetermined number of pixels and rearranging the transformed plural coefficient data according to a scan pattern indicating order of the coefficient data, the decoding circuit comprising:

• a pattern storing unit that stores scan pattern data for the scan pattern;
• a pattern writing unit that rewrites, according to the encoded data, the scan pattern data stored in the pattern storing unit into at least one scan pattern data for an encoding system of the encoded data;
• an information generating unit that generates, according to the encoded data, pattern selection information indicating a selection method for selecting one scan pattern data suitable for the encoded data out of the at least one scan pattern data stored in the pattern storing unit;
• a pattern readout unit that selects one scan pattern data suitable for the encoded data out of the at least one scan pattern data stored in the pattern storing unit using the pattern selection information and reads out the selected scan pattern data stored in the pattern storing unit;
• a coefficient restoring unit that restores the coefficient data from the encoded data;
• and
• an inverse scan processing unit that rearranges, according to the scan pattern data read out by the pattern readout unit, the coefficient data restored by the coefficient restoring unit.

A decoding method of decoding encoded data generated by image compression encoding for transforming image data into plural coefficient data in units of a block of a predetermined number of pixels and rearranging the transformed plural coefficient data according to a scan pattern indicating order of the coefficient data, the decoding method comprising:

• a pattern writing step of rewriting, with respect to a pattern storing unit that stores scan pattern data for the scan pattern, according to the encoded data, the scan pattern data stored in the pattern storing unit into at least one scan pattern data for an encoding system of the encoded data;
• an information generating step of generating, according to the encoded data, pattern selection information indicating a selection method for selecting one scan pattern data suitable for the encoded data out of the at least one scan pattern data stored in the pattern storing unit;
• a pattern readout step of selecting one scan pattern data suitable for the encoded data out of the at least one scan pattern data stored in the pattern unit using the pattern selection information and reading out the selected scan pattern data stored in the pattern storing unit;
• a coefficient restoring step of restoring the coefficient data from the encoded data;
• and
• an inverse scan processing step of rearranging, according to the scan pattern data read out in the pattern readout step, the coefficient data restored in the coefficient restoring step.

An encoding circuit that generates encoded data with image compression encoding for transforming image data into plural coefficient data in units of a block of a predetermined number of pixels and rearranging the transformed plural coefficient data according to a scan pattern indicating order of the coefficient data, the encoding circuit comprising:

• a pattern storing unit that stores scan pattern data for the scan pattern;
• a pattern writing unit that rewrites, according to the encoded data, the scan pattern data stored in the pattern storing unit into at least one scan pattern data for an encoding system of the encoded data;
• an information generating unit that generates, according to the encoded data, pattern selection information indicating a selection method for selecting one scan pattern data suitable for the encoded data out of the at least the scan pattern data stored in the pattern storing unit;
• a pattern readout unit that selects one scan pattern data suitable for the encoded data out of the at least the scan pattern data stored in the pattern storing unit using the pattern selection information and reads out the selected scan pattern data stored in the pattern storing unit;
• a coefficient generating unit that generates the coefficient data from the image data;
• and
• a scan processing unit that rearranges, according to the scan pattern data read out by the pattern readout unit, the coefficient data generated by the coefficient generating unit.

An encoding method of generating encoded data with image compression encoding for transforming image data into plural coefficient data in units of a block of a predetermined number of pixels and rearranging the transformed plural coefficient data according to a scan pattern indicating order of the coefficient data, the encoding method comprising:

• a pattern writing step of rewriting, with respect to a pattern storing unit that stores scan pattern data for the scan pattern, according to the encoded data, the scan pattern data stored in the pattern storing unit into at least one scan pattern data for the encoding system of the encoded data;
• an information generating step of generating, according to the encoded data, pattern selection information indicating a selection method for selecting one scan pattern data suitable for the encoded data out of the at least the scan pattern data stored in the pattern unit;
• a pattern readout step of selecting one scan pattern data suitable for the encoded data out of the at least one scan pattern data stored in the pattern storing unit using the pattern selection information and reading out the selected scan pattern data stored in the pattern storing unit;
• a coefficient generating step of generating the coefficient data from the image data;
• and
• a scan processing step of rearranging, according to the scan pattern data read out in the pattern readout step, the coefficient data generated in the coefficient generating step.