Find, manipulate and apply histograms and lookup tables [src]
Find, manipulate and apply histograms and lookup tables
Histograms and look-up tables are 1xn or nx1 images, where n is less than
256 or less than 65536, corresponding to 8- and 16-bit unsigned int images.
They are tagged with a VipsInterpretation of
VIPS_INTERPRETATION_HISTOGRAM and usually displayed by user-interfaces
such as nip2 as plots rather than images.
These functions can be broadly grouped as things to find or build
histograms (vips_hist_find(), vips_hist_find_indexed(),
vips_hist_find_ndim(), vips_buildlut(),
vips_identity()), operations that manipulate histograms in some way
(vips_hist_cum(), vips_hist_norm()),
operations to apply histograms (vips_maplut()), and a variety of
utility operations.
A final group of operations build tone curves. These are useful in pre-press work for adjusting the appearance of images. They are designed for CIELAB images, but might be useful elsewhere.