ref: 200239cdda62ba801df9c079a773cca999348a90
dir: ifilter/ifilter.man
.TH IFILTER 1 .SH NAME ifilter \- image filters .SH SYNOPSIS .B image/cfilter [ .B -f .I filter ] [ .B -r .I ratio ] .br .B image/blur [ .B -f .I type ] [ .B -r .I radius ] [ .B -s .I stddev ] .br .B image/pixelate [ .B -s .I size ] .br .B image/dither .SH DESCRIPTION These programs apply a filter on images read from the standard input and dump the resulting image on standard output. .TP .BR image/cfilter Applies a color filter to the input image. Possible filters are .IR grayscale , .IR sepia , .IR invert , .IR shade and .IR tint . The .IR shade and .IR tint filters use the .B -r parameter as a percentage .IR ratio between source and target colors. .PP .TP .B image/blur Applies a low-pass filter to blur the input image. Possible filters are .IR box , a simple filter using a 3x3 non-weighted convolution matrix or .IR gaussian , which uses a weighted convolution matrix of size 2 * .I radius + 1 (default radius is 2 leading to a 5x5 matrix) and a standard deviation of .I stddev (defaults to 1.0). .PP .TP .B image/pixelate Increases the pixel size of the input image to .I size (defaults to 8). .TP .B image/dither Applies a Floyd-Steinberg error diffusion based dithering algorithm to the input image. .SH AUTHOR phil9 .SH LICENSE MIT