equalize {EBImage} | R Documentation

## Histogram Equalization

### Description

Equalize the image histogram to a specified range and number of levels.

### Usage

    equalize(x, range = c(0, 1), levels = 256)

### Arguments

`x` | an `Image` object or an array
`range` | numeric vector of length 2, the output range of the equalized histogram
`levels` | number of grayscale levels (Grayscale images) or intensity levels of each channel (Color images)

### Details

Histogram equalization is an adaptive image contrast adjustment method. It flattens the image histogram by performing linearization of the cumulative distribution function of pixel intensities.

Individual channels of `Color` images and frames of image stacks are equalized separately.

### Value

An `Image` object or an array, containing the transformed version of `x`.

### Author(s)

Andrzej Oles, andrzej.oles@embl.de, 2014

### See Also

`clahe`

### Examples

      x = readImage(system.file('images', 'cells.tif', package='EBImage'))
      hist(x)
      y = equalize(x)
      hist(y)
      display(y, title='Equalized Grayscale Image')

      x = readImage(system.file('images', 'sample-color.png', package='EBImage'))
      hist(x)
      y = equalize(x)
      hist(y)
      display(y, title='Equalized Grayscale Image')

[Package EBImage version 4.22.1 Index]