contrib/mul/ipts/ipts_local_entropy.cxx File Reference

Compute entropy in region around each image pixel. More...

#include "ipts_local_entropy.h"
#include <vcl_vector.h>
#include <vcl_cmath.h>
#include <vcl_cassert.h>

Go to the source code of this file.

Functions
double	histo_entropy_sum (const vcl_vector< int > &histo, unsigned min_v, unsigned max_v)
void	ipts_local_entropy (const vil_image_view< vxl_byte > &image, vil_image_view< float > &entropy, unsigned h, unsigned min_v, unsigned max_v)
	Compute local entropy in square region around each pixel in image.

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Detailed Description

Compute entropy in region around each image pixel.

Author:

Tim Cootes

Definition in file ipts_local_entropy.cxx.

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Function Documentation

double histo_entropy_sum	(	const vcl_vector< int > &	histo,
		unsigned	min_v,
		unsigned	max_v
	)		[inline]

Definition at line 12 of file ipts_local_entropy.cxx.

void ipts_local_entropy	(	const vil_image_view< vxl_byte > &	image,
		vil_image_view< float > &	entropy,
		unsigned	h,
		unsigned	min_v,
		unsigned	max_v
	)

Compute local entropy in square region around each pixel in image.

For each pixel in image, compute entropy in region (2h+1)x(2h+1) centred on the pixel. Result put in entropy image, which is of size (image.ni()-2h) x (image.nj()-2h). Thus entropy(i,j) corresponds to the value in the box around image point (i+h,j+h).

Values in image are assumed to lie in the range [min_v,max_v]. Any values outside that range will be ignored in the entropy calculation.

Definition at line 29 of file ipts_local_entropy.cxx.