Hi, This post started as a request for help but has ended up as a FYI post.
I have quite a few jpegs with "extraneous bytes before marker 0xed". The images can be opened in PS, IrfanView and browsers so the corruption is not fatal but, mostly as an exercise, I wanted to try and remove the error. I could convert the files to remove the error but that would apply the encoding again and would lead to some, albeit minute, degradation of the image. What I wanted was to do is open the files in a hex editor, find the marker, delete x number of bytes before the marker and save the image. Trying to find the hex value was a little tough. After doing a lot of searching for 'ed' in Hex edit mode of WinVi32, the most obvious candidate looks like a section that reads like 00 00 00 00 ff ed 7d Where 00 goes back about 30 lines. So the marker sequence to find was "ff ed 7d". In the 3 cases I looked at the extraneous bytes were null or 00. So to remove the extra bytes, highlight the first null characters prior to 'ff ed' back to the first occurrence of 00 in that sequence. Delete the highlighted section, save the file with a new name. Open it in a graphics package and run identify to check that the image is sane. If your happy, overwrite original corrupted file with your new version. The only real benefit I have found in doing this is that graphics packages (namely PS) will open the file a little quicker. As far as I can tell this process has not tampered with any of the other file attributes such as ICC/IPTC/EXIF profiles and the preview image remains intact. Away, HTH. Dp. _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
