Hi Tom, I don't think anybody literate in computer imaging would
resave an edited jpeg back into jpeg. When I have a source image in
jpeg, I save it as a lossless format for all the editing steps. It is,
I hope, pretty much common knowledge that resaving jpeg is a no-no.
Actually, this is a common misconception, that you loose a huge amount of information when you save a image to jpg several times.
If you change something small in an image, only that part that changed will "loose" information. F.ex if you crop a jpg and save it to jpg, recrop it, save it to jpg.
That won't do much damage, _especially_ if you have a low compression level. (The bigger the compression level, the more you loose, ofcourse.)
To prove this point I took a random pic I have recently taken, cropped the original and saved it to medium-compression jpg.
Then I took the original, cropped it, saved it with medium compression, closed, opened, cropped, saved again with medium-compression, repeat step ten times.
So after 10 (!) times of recropping and recompressing the image (pretty heavily too, mind you) I have two images.
http://www.bicekru.org/~eatfrog/test1.jpg http://www.bicekru.org/~eatfrog/test2.jpg
Small pic, not very good detail, not the same size - I know, but it's 03:39 here and I want to get to bed now. ;-)
/Henri
