Am 21.04.2013 21:01, schrieb [email protected]: > I have a question about how the blend modes operate. > > They do not appear to match the usual algorithms, or output from other > editing software. For example, using the colorize module, the > following two cases don't work as I expected: > > - A difference blend with plain black image, should do nothing. > - A difference blend with a plain white image should invert the image. > > From looking at the code, I assume it's the clamping that's making > the difference?
The current implementation of the difference blend mode does not work correctly for modules in Lab color space. Reason is that there is no generally working definition how a difference in the a-channel or b-channel should be translated into the output. For that reason other software (PS) does not offer this blend mode for Lab images. darktable does but as said before the output is mostly useless. Ulrich ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter _______________________________________________ darktable-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-devel
