Histogram equalization filter.

Namespace:  AForge.Imaging.Filters
Assembly:  AForge.Imaging (in AForge.Imaging.dll) Version: (


public class HistogramEqualization : BaseInPlacePartialFilter


The filter does histogram equalization increasing local contrast in images. The effect of histogram equalization can be better seen on images, where pixel values have close contrast values. Through this adjustment, pixels intensities can be better distributed on the histogram. This allows for areas of lower local contrast to gain a higher contrast without affecting the global contrast.

The filter accepts 8 bpp grayscale images and 24/32 bpp color images for processing.

Note:For color images the histogram equalization is applied to each color plane separately.

Sample usage:

// create filter
HistogramEqualization filter = new HistogramEqualization( );
// process image
filter.ApplyInPlace( sourceImage );

Source image:

Result image:

Inheritance Hierarchy


See Also