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NormalizeLocalBrightness_Mean


Header: FIL.h
Namespace: fil
Module: FoundationBasic

Normalizes local brightness of the image. Internally uses Mean smoothing.

Applications: Compensates uneven illumination.

Syntax

C++
C#
 
void fil::NormalizeLocalBrightness_Mean
(
	const fil::Image& inImage,
	ftl::Optional<const fil::Region&> inRoi,
	int inRadiusX,
	ftl::Optional<int> inRadiusY,
	float inTargetMean,
	float inGammaValue,
	fil::Image& outImage
)

Parameters

Name Type Range Default Description
Input value
 inImage const Image& Input image
Input value
 inRoi Optional<const Region&> NIL Range of pixels to be processed
Input value
 inRadiusX int 0 - 10 Nearly half of the kernel's width (2*R+1)
Input value
 inRadiusY Optional<int> 0 - NIL Nearly half of the kernel's height (2*R+1), or same as inRadiusX
Input value
 inTargetMean float 128.0f Target mean brightness
Input value
 inGammaValue float 0.01 - 8.0 1.0f Gamma coefficient, where 1.0 is neutral
Output value
 outImage Image& Output image

Description

This filter normalizes every pixels brightness to inTargetMean based on a local average calculated using SmoothImage_Mean passing to it parameters inRadiusX and inRadiusY.

Gamma correction can be performed on the image before normalization through the inGammaValue parameter.

Examples

Example image

Output of NormalizeLocalBrightness_Mean

Hardware Acceleration

This operation supports automatic parallelization for multicore and multiprocessor systems.

See Also

  • NormalizeImage – Rescales an image linearly, so that its minimum becomes inNewMinimum and the maximum of the remaining pixels becomes inNewMaximum.
  • SmoothImage_Mean – Smooths an image by averaging pixels within a rectangular kernel.