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DifferenceImage_Shifted

Header:	AVL.h
Namespace:	avl
Module:	FoundationLite

Computes the non-negative distances between corresponding pixel values.

Applications: Useful for things like comparing an image against a template or for detecting differences between consecutive video frames.

Syntax

void avl::DifferenceImage_Shifted
(
	const avl::Image& inImage1,
	const avl::Image& inImage2,
	const avl::Box& inBox1,
	const avl::Box& inBox2,
	avl::Image& outImage
)

Parameters

Name	Type	Description
inImage1	const Image&	First input image
inImage2	const Image&	Second input image
inBox1	const Box&
inBox2	const Box&
outImage	Image&	Output image

Description

The operation computes the absolute difference between image pixels inside the input boxes. Each outImage pixel is equal to the absolute value of difference between corresponding pixels of the input images:

\[\forall_{i,j} \text{OutImage}_{i,j} = |\text{InImage1}_{i + box1.x,j + box1.y} - \text{InImage2}_{i + box2.x,j + box2.y}|\]

In multichannel (color) images each pixel channel is processed separately.

The operation requires that the images being processed have equal format and the input boxes have equal dimensions, otherwise an error with appropriate description occurs. To alter the pixel type of an image one can use ConvertPixelType filter. ConvertToMultichannel and AverageChannels filters allow to alter the number of image channels.

Examples

DifferenceImage_Shifted performed on the sample images.

Hardware Acceleration

This operation is optimized for SSE2 technology for pixels of types: UINT8, SINT8, UINT16, SINT16, REAL.

This operation is optimized for AVX2 technology for pixels of types: UINT8, SINT8, UINT16, SINT16, REAL.

This operation is optimized for NEON technology for pixels of types: UINT8, SINT8, UINT16, SINT16, SINT32, REAL.

This operation supports automatic parallelization for multicore and multiprocessor systems.

Errors

List of possible exceptions:

Error type	Description
DomainError	Image formats are not the same in DifferenceImage_Shifted.
DomainError	Input boxes are not completely inside the input images in DifferenceImage_Shifted.
DomainError	Not equal box dimensions in DifferenceImage_Shifted.