Image Filter Commands

  • f.sharpen=0..99 determines how much sharpening to apply when scaling the image.
  • f.sharpenwhen=always|downscaling|sizediffers determines when to sharpen.
  • down.filterdetermines the down-sampling filter to use. Must be one of robidoux, robidoux_sharp, robidoux_fast, ginseng, ginseng_sharp, lanczos, lanczos_sharp , lanczos_2, lanczos_2_sharp , cubic, cubic_sharp, catmull_rom, mitchell, cubic_b_spline, hermite, jinc, triangle, linear, box, fastest, n_cubic, n_cubic_sharp
  • up.filter determines the up-sampling filter to use. See down.filter
  • down.colorspace=srgb downscales in the srgb color space instead of linear RGB. Mimics widespread but bad behavior; destroys image highlights.
  • s.grayscale=true|y|ry|ntsc|bt709|flat transforms the image into grayscale using various methods.
  • s.sepia=true turns the image into sepia tone
  • s.invert=true inverts the image colors in the srgb space
  • s.alpha=0..1 makes the image partially transparent
  • s.contrast=-1..1 adjusts the contrast in the srgb space
  • s.brightness=-1..1 adjusts brightness in the srgb space
  • s.saturation=-1..1 adjusts saturation in the srgb space