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ColorDistance


Header: AVL.h
Namespace: avl
Module: FoundationPro

Compares two pixels using chromatic and non-chromatic information. Assumes RGB color space.

Applications: Color comparison insensitive to changes of illumination.

Syntax

C++
C#
 
void avl::ColorDistance
(
	const avl::Pixel& inPixelA,
	const avl::Pixel& inPixelB,
	float inChromaAmount,
	float& outDistance
)

Parameters

Name Type Range Default Description
Input value inPixelA const Pixel&
Input value inPixelB const Pixel&
Input value inChromaAmount float 0.0 - 1.0 0.7f Proportion of chromatic information in distance computation
Output value outDistance float&

Description

The operation computes the distance between two pixels.

The distance between pixels is computed using two measures:

  • Value distance - the difference between average channel values
  • Chromatic distance - euclidean distance between pixels normalized to the same value level

The resulting distance is computed as a weighted average of these two values, parameter inChromaAmount ( 0.0 - 1.0 ) being the weight of the chromatic distance, and 1 - inChromaAmount being the weight of the value distance.

Errors

List of possible exceptions:

Error type Description
RuntimeError Each pixel component must be nonnegative in ColorDistance.

See Also

  • ColorDistanceImage – Compares each pixel with the specified color using chromatic and non-chromatic information.