DifferenceImage

Header:	AVL.h
Namespace:	avl

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
(
	const avl::Image& inImage1,
	const avl::Image& inImage2,
	atl::Optional<const avl::Region&> inRoi,
	avl::Image& outImage
)

Parameters

Name	Type	Default	Description
inImage1	const Image&		First input image
inImage2	const Image&		Second input image
inRoi	Optional<const Region&>	NIL	Range of pixels to be processed
outImage	Image&		Output image

In-place Processing

This function supports in-place data processing - you can pass the same reference to inImage1 and outImage, inImage2 and outImage

Description

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

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

The operation requires that the images being processed have equal format and dimensions, otherwise an error with appropriate description occurs. To obtain an image of desired dimensions one can use ResizeImage or CropImage filter. 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 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.
DomainError	Image sizes are not equal in DifferenceImage.
DomainError	Region exceeds an input image in DifferenceImage.