Libvips Histogram

Title: Operator index > By section > Histogram

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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 [enum@Interpretation] of [[email protected]] 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 ([[email protected]_find], [[email protected]_find_indexed], [[email protected]_find_ndim], [[email protected]], [[email protected]]), operations that manipulate histograms in some way ([[email protected]_cum], [[email protected]_norm]), operations to apply histograms ([[email protected]]), 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.

Functions

• [[email protected]]
• [[email protected]]
• [[email protected]]
• [[email protected]_cum]
• [[email protected]_norm]
• [[email protected]_equal]
• [[email protected]_plot]
• [[email protected]_match]
• [[email protected]_local]
• [[email protected]_ismonotonic]
• [[email protected]_entropy]
• [[email protected]]