This option is therefore only provided for transforming (scaling) algorithms and is the default value. Lanczos3 can cause pixel overshoots leading to artefacts but sometimes gives a more crisp visual appearance. The same options are provided as for the warp modules, but with the addition of lanczos3. pixel interpolator (scaling) The pixel interpolator used for scaling. In general, bicubic is a safe option for most cases and is the default value. For warping modules, darktable offers bilinear, bicubic or lanczos2. Whenever we scale or distort an image we have to choose a pixel interpolation algorithm (see wikipedia for details). pixel interpolator (warp) The pixel interpolator used for rotation, lens correction, liquify, crop and final scaling. If the given ICC is LUT-based or contains both a LUT and a matrix, darktable will use LittleCMS 2 to render the colors regardless of this parameter’s value (default off). This is significantly slower than the default but might give more accurate results in some cases. 🔗image processing always use LittleCMS 2 to apply output color profile If this option is activated, darktable will use the LittleCMS 2 system library to apply the output color profile instead of its own internal routines.

Darktable github