jpegjudge - 0.0.2-5 main

Try to determine which same picture was saved at a higher quality,
even if the picture was saved at low quality and later at a higher
quality.
.
By a statistical analysis over the quantization table stored in a
jpeg one could probably deduce the quality which the picture was
saved (i.e. this particular save), but it in no way says anything
about the picture quality itself (i.e. whether it has ever been saved
at lower quality before since its creation). For example, one might have
saved a jpeg picture at low quality, and later saved at a higher
quality, yet the information lost during the first save can't be
restored.