colormap {EBImage} | R Documentation

## Map a Greyscale Image to Color

### Description

Maps a greyscale image to color using a color palette.

### Usage

    colormap(x, palette = heat.colors(256L))

### Arguments

`x` | an `Image` object of color mode `Grayscale`, or an array
`palette` | character vector containing the color palette

### Details

The `colormap` function first linearly maps the pixel intensity values of `x` to the integer range `1:length(palette)`. It then uses these values as indices to the provided color palette to create a color version of the original image.

The default palette contains 256 colors, which is the typical number of different shades in a 8bit grayscale image.

### Value

An `Image` object of color mode `Color`, containing the color-mapped version of `x`.

### Author(s)

Andrzej Oleś, andrzej.oles@embl.de, 2016

### Examples

      x = readImage(system.file("images", "sample.png", package="EBImage"))

      ## posterize an image using the topo.colors palette
      y = colormap(x, topo.colors(8))

      display(y, method="raster")

      ## mimic MatLab's 'jet.colors' colormap
      jet.colors = colorRampPalette(c("#00007F", "blue", "#007FFF", "cyan", "#7FFF7F", "yellow", "#FF7F00", "red", "#7F0000"))
      y = colormap(x, jet.colors(256))

      display(y, method="raster")

[Package EBImage version 4.22.1 Index]