On Fri, Jan 03, 2020 at 04:25:32PM -0800, jys wrote: > > > > > First of all I wonder why the dtstyle created by darktable-chart > > > includes the module "input color profile". > > Probably to make sure the input profile being used with the > applied style is the same one that was used to create the style > in the first place, otherwise the results won't be valid. Did > you create the style using a camera RAW file and its associated > "standard" color matrix?
I created the dtstyle from a regular JPEG file, not RAW image; I'm experimenting with scanner color balance, not camera profiling. Indeed it seems that I have to deal with the "input color profile" of my source images. The one added by darktable-chart is wrong and must be replaced. To be more clear, this is the workflow that now works: 1) Make a scan of the ColorChecker chart, open it in Darktable, assign the most appropriate "input color profile" (which was "linear Rec2020 RGB" in my case) export the image in PFM float format, Lab color profile. 2) Get a reference image of the same ColorChecker chart, i.e. one image with exactly calibrated colors. Export this image too in PFM float, Lab. 3) Launch darktable-chart and use image #1 as "source image" and image #2 as "reference values". Process the images and save the resulting dtstyle. NOTICE: darktable-chart will include an "input color profile" into the style, called "standard color matrix" which is indeed wrong. We will replace it later. 4) Launch Darktable, import the dtstyle created at step #3. 5) Open the image to be color balanced, apply the proper "input color profile" (again it was "linear Rec2020 RGB" in my case). 6) Apply the style imported in step 4 to the image and check the history of the image: remove the last "input color porfile" applied by the style. The image should now be correctly balanced. 7) Save the image history as a new style, this is the only one that you will apply to all other images. Happy Color Balancing! -- Niccolo Rigacci - http://www.rigacci.net/ Campi Bisenzio - Firenze - Italy Tel. Mobile: +39-327-5619352 ____________________________________________________________________________ darktable user mailing list to unsubscribe send a mail to darktable-user+unsubscr...@lists.darktable.org