NAME

lerp, sub - linear combinations of images

SYNOPSIS

fb/lerp file fraction [ file fraction ... ]

fb/sub file1 file2

DESCRIPTION

Lerp computes a linear combination of a number of input images. Each input file name is followed by a floating-point fraction by which to scale its pixel values. The fraction after the last image may be omitted, in which case one minus the sum of the other fractions is used. The resulting image is written to standard output.

Nothing prevents the fractions from being smaller than zero or larger than one. Output pixel values that fall below zero or above 255 are clamped.

Sub reads two images, which must be the same size and have the same number of channels. Each channel of each pixel of the output image is the absolute value of the difference between the corresponding input values.

SOURCE

/sys/src/fb/lerp.c
/sys/src/fb/sub.c

SEE ALSO

picfile(9.6)