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image_pyramid.h File Reference

#include <gandalf/image/image_defs.h>

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Compounds

struct  Gan_ImagePyramid
 Structure to hold image and mask at a single pyramid level. More...


Typedefs

typedef Gan_ImagePyramid Gan_ImagePyramid
 Structure to hold image and mask at a single pyramid level.

typedef enum Gan_ImagePyramidAverage Gan_ImagePyramidAverage
 Type of averaging used when combining four pixels into one.


Enumerations

enum  Gan_ImagePyramidAverage { GAN_AVERAGE_ALL, GAN_AVERAGE_IN_MASK }
 Type of averaging used when combining four pixels into one. More...


Functions

Gan_Bool gan_image_pyramid_build (Gan_Image *img, Gan_Image *mask, unsigned no_levels, Gan_ImagePyramidAverage average_type, unsigned no_neighbours, Gan_ImagePyramid **pyramid)
 Builds an image pyramid.

void gan_image_pyramid_free (Gan_ImagePyramid *pyramid, unsigned no_levels, Gan_Bool free_top_level)
 Frees an image pyramid.


Detailed Description

Module: Construct multi-resolution image pyramid

Part of: Gandalf Library

Revision: Last edited: Author:

Copyright: (c) 2000 Imagineer Software Limited


Enumeration Type Documentation

enum Gan_ImagePyramidAverage
 

Type of averaging used when combining four pixels into one.

Enumeration values:
GAN_AVERAGE_ALL  take average of all four pixels
GAN_AVERAGE_IN_MASK  take average only of pixels in the mask


Function Documentation

Gan_Bool gan_image_pyramid_build Gan_Image   img,
Gan_Image   mask,
unsigned    no_levels,
Gan_ImagePyramidAverage    average_type,
unsigned    no_neighbours,
Gan_ImagePyramid **    pyramid
 

Builds an image pyramid.

Parameters:
img The top-level image in the pyramid
mask The mask corresponding to the top-level image or NULL
no_levels The number of levels in the pyramid
average_type The type of averaging of four-pixel neighbourhoods
no_neighbours Minimum number of neighbours set to transfer resolution
pyramid Pointer to the pyramid
Returns:
GAN_TRUE on success, GAN_FALSE on failure.
Builds an image pyramid. If the mask is NULL, the pyramid is built without masks, i.e. assuming that all the pixels are valid.

no_neighbours is the least number of number of pixels in any four-pixel neighbourhood of mask pixels needed to be one in order for the lower resolution mask to be set to one.

See also:
gan_image_pyramid_free().

void gan_image_pyramid_free Gan_ImagePyramid   pyramid,
unsigned    no_levels,
Gan_Bool    free_top_level
 

Frees an image pyramid.

Parameters:
pyramid Pointer to the pyramid
no_levels The number of levels in the pyramid
free_top_level Whether to free the top level image
Returns:
GAN_TRUE on success, GAN_FALSE on failure.
Frees an image pyramid. The free_top_levels flag indicates whether the top-level image should be freed.

See also:
gan_image_pyramid_build().


Generated on Mon Oct 13 16:14:42 2003 by doxygen1.3-rc1