Hi, Am Samstag, den 03.11.2018, 19:11 +0100 schrieb Stéphane Gourichon: > Applying the principle of least surprise invites me to suggest an > idea: defaulting to roughly same image file weight. > # Idea, with details > So, how about implementing, like GIMP does, an option like this: > > [✔] Use quality settings from original image (when available)
I agree abot the principle, but I think file size is not the relevant point when talking about images. For me, the main point is that darktable preserves the image quality of an input image as far as possible, even when it is in a lossy format like JPEG. The idea of re-using quantisation tables can make sense, I am not a programmer. But re-using the "quality settings" as presented to the user seems a bad idea. The numbers on the JPEG quality scale are not standardized. One program's "70" may be another program's "90" and so on. So (possibly) downgrading an image of higher quality until it meets darktable's JPEG quality numbering scheme would be a bad idea, at least as a default. This would be a surprise for me. On the other hand, there may be a neat way to calculate the necessary quality of a JPEG for the given information content of an imported file. So darktable could determine that a darktable-specific setting of "83" is required to transport all the valid information from an input file that has been saved in another program with a setting of "70" or "90" (according to that program's scale). This would be a fine way to deal with the file size issue mentioned earlier (but even then, it may be considered surprising if darktable did this by default). Cheers Michael ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org
