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EqualizeImageHistogram

Module:	FoundationLite

Maps image pixels to new values to achieve uniform distribution of intensities in the range (0, 255).

Name	Type	Range	Description
inImage	Image		Input image
inRoi	Region *		Range of pixels to be processed
inSaturateBrightestFraction	Real	0.0 - 1.0	Fraction of the brightest pixels skipped during normalization
inSaturateDarkestFraction	Real	0.0 - 1.0	Fraction of the darkest pixels skipped during normalization
outImage	Image		Output image

Requirements

For input inImage only pixel formats are supported: 1⨯uint8.

Read more about pixel formats in Image documentation.

Description

The filter applies non-linear mapping to image pixel values so that pixel intensities of the resulting image are evenly distributed in range from 0 to 255.

The operation computes the cumulative histogram \(C\) of inImage and the image size \(N\). Then the result is computed as follows:

\[ \begin{aligned} outImage[i,j] &= C[ inImage[i,j] ] \times \frac{255}{N} \end{aligned} \]

Examples

EqualizeImageHistogram run on example image.

Errors

This filter can throw an exception to report error. Read how to deal with errors in Error Handling.

List of possible exceptions:

Error type	Description
DomainError	Region exceeds an input image in EqualizeImageHistogram.
DomainError	The sum of inSaturateBrightestFraction and inSaturateDarkestFraction can't be greater than 1 in EqualizeImageHistogram.
DomainError	Not supported inImage pixel format in EqualizeImageHistogram.

Complexity Level