VIPS operation API by section

arithmetic — operations which perform pixel arithmetic, trig, log, statistics
boolean — boolean algebra on images, bitshifts
relational — relational comparisons between pairs of images and images and constants
colour — colour operators
conversion — convert images in some way: change band format, change header, insert, extract, join
convolution — convolve and correlate images
VipsFormat — load and save in a variety of formats
freq_filt — fourier transforms and frequency-domin filters
histograms_lut — find, manipulate and apply histograms and lookup tables