JPEG Decompression Plugin
The JPEG decompression plugin is an extension to the library, implemented with the IJG's libjpeg∞
. It currently handles C3 and M3 imagery. It does handle data with builtin Huffman and Quantization tables. It does not handle data where the tables are defaulted using the NITF MIL STD, though extending it to support this is definitely possible. This plugin originated in 2004, and updates were made in early 2008 to support M3 and to support multiple event registration by plugin handlers. The plugin was also recently modified to reuse file descriptors between block read calls.
The plugin currently does not cache blocks internally, although adding this capability is certainly not too difficult. The read function would simply lookup the block number to see if it exists in the cache, before decompressing and returning the block.