hi
http://www.gsp.com/cgi-bin/man.cgi?section=1&topic=jpegtran """ We also offer a lossless-crop option, which discards data outside a given image region but losslessly preserves what is inside. Like the rotate and flip transforms, lossless crop is restricted by the current JPEG format: the upper left corner of the selected region must fall on an iMCU boundary. If this does not hold for the given crop parameters, we silently move the upper left corner up and/or left to make it so, simultaneously increasing the region dimensions to keep the lower right crop corner unchanged. (Thus, the output image covers at least the requested region, but may cover more.) The image can be losslessly cropped by giving the switch: -crop WxH+X+Y Crop to a rectangular subarea of width W, height H starting at point X,Y. """ not sure if this is what we are looking for... ciao a.l.e
