Most JPEG decoders (internal in many computer programs) decode the JPEG images in a quick-and-simple way, giving some typical noise problems. Some of those problems may be reduced on post processing, but if we use noise reduction techniques inside the JPEG decoder, we can take profit of all the JPEG information, instead of only the conventionally decoded image.
Here you have a restoration example from a low quality JPEG:
Trying to collect the state of the art of the JPEG restoration algorithms, I found the next evidences:
Therefore, I thought I could provide some software which:
Look at some screenshots.
I still have not written any manual in English. You should better look at the example video (15MB, DivX, without audio), and send me a letter if you don't understand something. Oh, you may not be able to guess that Control+LeftClick and Control+RightClick alllow the image zooms.
On Linux and Macintosh OS X:
Download the latest version (GPLv2 licensed, taking some bits from MegaWave 2): qjpegrest-0.5.tar.gz - v0.5 (around 100KB)
You can download a Linux 2.6 dynamic executable which requires Qt 4.3 and libjpeg: qjpegrest-0.5.gz - v0.5 (around 190KB)
You can download a MacOSX static executable: qjpegrest-0.5.dmg - v0.5 (around 4MB)