int im_invert(in, out)
IMAGE *in, *out;
DESCRIPTIONim_invert inverts the image held by image descriptor in and writes the result on the image descriptor out. The function works on FMTUCHAR images only. The result at point x of the input image is 255-x at the output image. Input can have any no of channels.
This is not a generally useful program -- it is included as an example of a very simple new-style IO function. Feel the power of the source, Luke!
RETURN VALUEThe function returns 0 on success and -1 on error.
AUTHORJ. Cupitt - 21/7/93