On lundi 17 décembre 2007, Martin Ling wrote: > 100 patches is not very many at all, especially for an uncalibrated LCD > device. In my experience the targen default of 836 patches produced a > reasonable profile for my laptop display, while increasing this to 2000 > got me better results in awkward dark areas. See also the guidance on > patch counts in http://www.argyllcms.com/doc7/targen.html of course. I will try to increase the number of patches... > I think (Graham can no doubt confirm) that there's just cctiff. The fact > there's a quality option on the lcms tool at all suggests that it's > decompressing the JPEG, operating on the resulting image and then > recompressing. This is the most straightforward way of doing it but will > inevitably lead to degradation unless knowledge of the structure of the > original compressed data is used. > > I think you will probably get the best results possible by converting > the image to TIFF, applying the colour transformation with cctiff, and > then reconverting to JPEG using the same subsampling settings and > quantisation tables as were used in saving the original images. The > cjpeg tool from the libjpeg project will let you specify these settings, > which should be possible to determine somehow from the SOF and DQT > markers in the original image. Ok, I'll do that. Thanks ! -- Frédéric http://www.gbiloba.org