Image Filters

Image filters allow control of shades and colors of the pixels in the image.

QueryString API

• 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.

• up.colorspace=srgb up-scales in the srgb color space instead of linear RGB.

• 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