Method and apparatus for a memory efficient approach for decoding progressive joint photographic experts group (jpeg) images

An apparatus for a memory efficient approach for decoding progressive JPEG images comprising:

• a computer having one or more processors and further comprising:
• a decoding module for (a) accessing a progressive JPEG image, wherein the progressive JPEG image comprises a plurality of compressed scans and wherein each scan in the plurality of scans comprises a plurality of compressed rows of image data;
• (b) decompressing not more than half of the compressed rows of each scan in the plurality of scans into a memory buffer;
• (c) copying a remaining plurality of compressed rows of each scan in the plurality of scans into a plurality of small memory buffers;
• (d) decoding, in place, the decompressed rows in the memory buffer;
• and (e) repeating steps (b)-(d) until a predefined number of rows are remaining in the plurality of small memory buffers, at which time the remaining rows are decompressed and decoded.

A non-transient computer readable medium for storing computer instructions that, when executed by at least one processor causes the at least one processor to perform a method for a memory efficient approach for decoding progressive JPEG images comprising:

• (a) accessing a progressive JPEG image, wherein the progressive JPEG image comprises a plurality of compressed scans and wherein each scan in the plurality of scans comprises a plurality of compressed rows of image data;
• (b) decompressing not more than half of the compressed rows of each scan in the plurality of scans into a memory buffer;
• (c) copying a remaining plurality of compressed rows of each scan in the plurality of scans into a plurality of small memory buffers;
• (d) decoding, in place, the decompressed rows in the memory buffer;
• and
• (e) repeating steps (b)-(d) until a predefined number of rows are remaining in the plurality of small memory buffers, at which time the remaining rows are decompressed and decoded.