cmpermute

Rearrange colors in colormap

Syntax

[Y,newmap] = cmpermute(X,map)

[Y,newmap] = cmpermute(X,map,index)

Description

[Y,newmap] = cmpermute(X,map) randomly reorders the colors in colormap map to produce a new colormap, newmap. The cmpermute function also modifies the values in indexed image X to maintain correspondence between the indices and the colormap, and returns the result in Y. The image Y and associated colormap, newmap, produce the same image as X and map.

[Y,newmap] = cmpermute(X,map,index) uses an ordering matrix (such as the second output of sort) to define the order of colors in the new colormap.

Examples

Randomly Reorder Colormap and Display Image

Read the first image, X, and its associated colormap, map, from the sample indexed image file, corn.tif. Display the image.

[X,map] = imread('corn.tif');
imshow(X,map)

Randomly reorder the colormap to get a new colormap, newmap. Display image X with the new colormap.

[Y,newmap] = cmpermute(X,map);
colormap(newmap)

Input Arguments

X — Indexed image

m-by-n matrix of integers

Indexed image, specified as an m-by-n matrix of integers.

Data Types: double | uint8

map — Colormap

c-by-3 matrix

Colormap associated with indexed image X, specified as a c-by-3 matrix with values in the range [0, 1]. Each row of map is a three-element RGB triplet that specifies the red, green, and blue components of a single color of the colormap.

Data Types: double

index — Sort index

c-element vector of positive integers

Sort index, specified as a c-element vector of positive integers.

Data Types: double

Output Arguments

Y — Indexed image

m-by-n matrix of integers

Indexed image, returned as an m-by-n matrix of integers. Y has the same data type as input indexed image X.

Data Types: double | uint8

newmap — Colormap with reduced colors

c-by-3 matrix

Colormap with reduced colors associated with the output indexed image Y, returned as a c-by-3 matrix with values in the range [0, 1]. Each row of newmap is a three-element RGB triplet that specifies the red, green, and blue components of a single color of the colormap.

Data Types: double

Version History

Introduced before R2006a