IM: Convolution Operations

IM - An Imaging Tool

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Convolution Operations
[Image Processing]

Detailed Description

: See im_process_loc.h


Modules
	Kernel Generators
Functions
int	imProcessConvolve (const imImage src_image, imImage dst_image, const imImage *kernel)
int	imProcessConvolveSep (const imImage src_image, imImage dst_image, const imImage *kernel)
int	imProcessConvolveDual (const imImage src_image, imImage dst_image, const imImage kernel1, const imImage kernel2)
int	imProcessConvolveRep (const imImage src_image, imImage dst_image, const imImage *kernel, int count)
int	imProcessCompassConvolve (const imImage src_image, imImage dst_image, imImage *kernel)
void	imProcessRotateKernel (imImage *kernel)
int	imProcessDiffOfGaussianConvolve (const imImage src_image, imImage dst_image, float stddev1, float stddev2)
int	imProcessLapOfGaussianConvolve (const imImage src_image, imImage dst_image, float stddev)
int	imProcessMeanConvolve (const imImage src_image, imImage dst_image, int kernel_size)
int	imProcessGaussianConvolve (const imImage src_image, imImage dst_image, float stddev)
int	imProcessBarlettConvolve (const imImage src_image, imImage dst_image, int kernel_size)
int	imProcessSobelConvolve (const imImage src_image, imImage dst_image)
int	imProcessPrewittConvolve (const imImage src_image, imImage dst_image)
int	imProcessSplineEdgeConvolve (const imImage src_image, imImage dst_image)
void	imProcessZeroCrossing (const imImage src_image, imImage dst_image)
void	imProcessCanny (const imImage src_image, imImage dst_image, float stddev)
int	imGaussianStdDev2KernelSize (float stddev)
float	imGaussianKernelSize2StdDev (int kernel_size)

Function Documentation

int imProcessConvolve	(	const imImage *	src_image,
		imImage *	dst_image,
		const imImage *	kernel
	)

Base Convolution with a kernel.
Kernel can be IM_INT or IM_FLOAT, but always IM_GRAY. Use kernel size odd for better results.
Supports all data types. The border is mirrored.
Returns zero if the counter aborted. Most of the convolutions use this function.
If the kernel image attribute "Description" exists it is used by the counter.

im.ProcessConvolve(src_image: imImage, dst_image: imImage, kernel: imImage) -> counter: boolean [in Lua 5]

im.ProcessConvolveNew(image: imImage, kernel: imImage) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessConvolveSep	(	const imImage *	src_image,
		imImage *	dst_image,
		const imImage *	kernel
	)

Base convolution when the kernel is separable. Only the first line and the first column will be used.
Returns zero if the counter aborted.
If the kernel image attribute "Description" exists it is used by the counter.

im.ProcessConvolveSep(src_image: imImage, dst_image: imImage, kernel: imImage) -> counter: boolean [in Lua 5]

im.ProcessConvolveSepNew(image: imImage, kernel: imImage) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessConvolveDual	(	const imImage *	src_image,
		imImage *	dst_image,
		const imImage *	kernel1,
		const imImage *	kernel2
	)

Base Convolution with two kernels. The result is the magnitude of the result of each convolution.
Kernel can be IM_INT or IM_FLOAT, but always IM_GRAY. Use kernel size odd for better results.
Supports all data types. The border is mirrored.
Returns zero if the counter aborted. Most of the convolutions use this function.
If the kernel image attribute "Description" exists it is used by the counter.

im.ProcessConvolveDual(src_image: imImage, dst_image: imImage, kernel1, kernel2: imImage) -> counter: boolean [in Lua 5]

im.ProcessConvolveDualNew(image: imImage, kernel1, kernel2: imImage) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessConvolveRep	(	const imImage *	src_image,
		imImage *	dst_image,
		const imImage *	kernel,
		int	count
	)

Repeats the convolution a number of times.
Returns zero if the counter aborted.
If the kernel image attribute "Description" exists it is used by the counter.

im.ProcessConvolveRep(src_image: imImage, dst_image: imImage, kernel: imImage, count: number) -> counter: boolean [in Lua 5]

im.ProcessConvolveRepNew(image: imImage, kernel: imImage, count: number) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessCompassConvolve	(	const imImage *	src_image,
		imImage *	dst_image,
		imImage *	kernel
	)

Convolve with a kernel rotating it 8 times and getting the absolute maximum value.
Kernel must be square.
The rotation is implemented only for kernel sizes 3x3, 5x5 and 7x7.
Supports all data types except IM_CFLOAT. Returns zero if the counter aborted.
If the kernel image attribute "Description" exists it is used by the counter.

im.ProcessCompassConvolve(src_image: imImage, dst_image: imImage, kernel: imImage) -> counter: boolean [in Lua 5]

im.ProcessCompassConvolveNew(image: imImage, kernel: imImage) -> counter: boolean, new_image: imImage [in Lua 5]

void imProcessRotateKernel

(

imImage *

kernel

)

Utility function to rotate a kernel one time.

im.ProcessRotateKernel(kernel: imImage) [in Lua 5]

int imProcessDiffOfGaussianConvolve	(	const imImage *	src_image,
		imImage *	dst_image,
		float	stddev1,
		float	stddev2
	)

Difference(Gaussian1, Gaussian2).
Supports all data types, but if source is IM_BYTE or IM_USHORT destiny image must be of type IM_INT.

im.ProcessDiffOfGaussianConvolve(src_image: imImage, dst_image: imImage, stddev1: number, stddev2: number) -> counter: boolean [in Lua 5]

im.ProcessDiffOfGaussianConvolveNew(image: imImage, stddev1: number, stddev2: number) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessLapOfGaussianConvolve	(	const imImage *	src_image,
		imImage *	dst_image,
		float	stddev
	)

Convolution with a laplacian of a gaussian kernel.
Supports all data types, but if source is IM_BYTE or IM_USHORT destiny image must be of type IM_INT.

im.ProcessLapOfGaussianConvolve(src_image: imImage, dst_image: imImage, stddev: number) -> counter: boolean [in Lua 5]

im.ProcessLapOfGaussianConvolveNew(image: imImage, stddev: number) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessMeanConvolve	(	const imImage *	src_image,
		imImage *	dst_image,
		int	kernel_size
	)

Convolution with a kernel full of "1"s inside a circle.
Supports all data types.

im.ProcessMeanConvolve(src_image: imImage, dst_image: imImage, kernel_size: number) -> counter: boolean [in Lua 5]

im.ProcessMeanConvolveNew(image: imImage, kernel_size: number) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessGaussianConvolve	(	const imImage *	src_image,
		imImage *	dst_image,
		float	stddev
	)

Convolution with a float gaussian kernel.
If sdtdev is negative its magnitude will be used as the kernel size.
Supports all data types.

im.ProcessGaussianConvolve(src_image: imImage, dst_image: imImage, stddev: number) -> counter: boolean [in Lua 5]

im.ProcessGaussianConvolveNew(image: imImage, stddev: number) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessBarlettConvolve	(	const imImage *	src_image,
		imImage *	dst_image,
		int	kernel_size
	)

Convolution with a barlett kernel.
Supports all data types.

im.ProcessBarlettConvolve(src_image: imImage, dst_image: imImage, kernel_size: number) -> counter: boolean [in Lua 5]

im.ProcessBarlettConvolveNew(image: imImage, kernel_size: number) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessSobelConvolve	(	const imImage *	src_image,
		imImage *	dst_image
	)

Magnitude of the sobel convolution.
Supports all data types.

im.ProcessSobelConvolve(src_image: imImage, dst_image: imImage) -> counter: boolean [in Lua 5]

im.ProcessSobelConvolveNew(image: imImage) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessPrewittConvolve	(	const imImage *	src_image,
		imImage *	dst_image
	)

Magnitude of the prewitt convolution.
Supports all data types.

im.ProcessPrewittConvolve(src_image: imImage, dst_image: imImage) -> counter: boolean [in Lua 5]

im.ProcessPrewittConvolveNew(image: imImage) -> counter: boolean, new_image: imImage [in Lua 5]

int imProcessSplineEdgeConvolve	(	const imImage *	src_image,
		imImage *	dst_image
	)

Spline edge dectection.
Supports all data types.

im.ProcessSplineEdgeConvolve(src_image: imImage, dst_image: imImage) -> counter: boolean [in Lua 5]

im.ProcessSplineEdgeConvolveNew(image: imImage) -> counter: boolean, new_image: imImage [in Lua 5]

void imProcessZeroCrossing	(	const imImage *	src_image,
		imImage *	dst_image
	)

Finds the zero crossings of IM_INT and IM_FLOAT images. Crossings are marked with non zero values indicating the intensity of the edge. It is usually used after a second derivative, laplace.
Extracted from XITE, Copyright 1991, Blab, UiO
http://www.ifi.uio.no/~blab/Software/Xite/

im.ProcessZeroCrossing(src_image: imImage, dst_image: imImage) [in Lua 5]

im.ProcessZeroCrossingNew(image: imImage) -> new_image: imImage [in Lua 5]

void imProcessCanny	(	const imImage *	src_image,
		imImage *	dst_image,
		float	stddev
	)

First part of the Canny edge detector. Includes the gaussian filtering and the nonmax suppression.
After using this you could apply a Hysteresis Threshold, see imProcessHysteresisThreshold.
Image must be IM_BYTE/IM_GRAY.
Implementation from the book:

    J. R. Parker
    "Algoritms for Image Processing and Computer Vision"
    WILEY

im.ProcessCanny(src_image: imImage, dst_image: imImage, stddev: number) [in Lua 5]

im.ProcessCannyNew(image: imImage, stddev: number) -> new_image: imImage [in Lua 5]

int imGaussianStdDev2KernelSize

(

float

stddev

)

Calculates the kernel size given the standard deviation.
If sdtdev is negative its magnitude will be used as the kernel size.

im.GaussianStdDev2KernelSize(stddev: number) -> kernel_size: number [in Lua 5]

float imGaussianKernelSize2StdDev

(

int

kernel_size

)

Calculates the standard deviation given the kernel size.

im.GaussianKernelSize2StdDev(kernel_size: number) -> stddev: number [in Lua 5]

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IM: Convolution Operations

IM - An Imaging Tool

Convolution Operations [Image Processing]

Detailed Description

Modules

Functions

Function Documentation

Convolution Operations
[Image Processing]