HistogramEqualize Class

Syntax

Public NotInheritable Class HistogramEqualize _
	Inherits PerChannelBitmapTransform

public sealed class HistogramEqualize : PerChannelBitmapTransform

Remarks

Histogram equalization algorithm is used to automatically enhance a contrast of the image. As usual it makes the image too posterized, that's why it is seldom used to with photos (you should use Contrast effect with Auto property set to true). However it suits for scientific tasks (as a preparation before applying some specific algorithm like vectorization, recognition, etc).

Main idea of this algorithm is to build such look-up table (LUT) which makes the bitmap histogram equalized (all histogram entries are equal each other). Actually the histogram is never equalized absolutely, however this algorithm makes it as much as possible. After that this LUT is applied using ApplyLut class.

This class enables you to use not only histogram of the source bitmap, but any other histogram too. In this case algorithm will build the LUT for this histogram, but apply this LUT on the source bitmap. To specify another histogram, use property Histogram. If you want to get histogram from the bitmap automatically, set null to this property.

As long as this class is inherited from PerChannelBitmapTransform class, you can equalize histogram for specific channels. Just use Channels property, SelectAllChannels(), and DeselectAllChannels() methods in the common way for this.

Inheritance Hierarchy

Thread Safety

Object Model

Supported Pixel Formats

See Also

Reference

• HistogramEqualize Members
• Aurigma.GraphicsMill.Transforms Namespace