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im_gaussnoise gtkdoc

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This commit is contained in:
John Cupitt 2010-01-29 14:35:09 +00:00
parent 58eae72a15
commit 996e4407d5
2 changed files with 22 additions and 28 deletions
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2
libvips/conversion/im_black.c
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@ -75,7 +75,7 @@ black_gen( REGION *or, void *seq, void *a, void *b )
* *
* Make a black unsigned char image of a specified size. * Make a black unsigned char image of a specified size.
* *
* See also: im_make_xy(), im_text(). * See also: im_make_xy(), im_text(), im_gaussnoise().
* *
* Returns: 0 on success, -1 on error * Returns: 0 on success, -1 on error
*/ */

48
libvips/conversion/im_gaussnoise.c
View File

@ -1,15 +1,4 @@
/* @(#) Creates a Gaussian noisy float image with mean of 0 and variance of 1 /* im_gaussnoise
* @(#) by averaging 12 random numbers
* @(#) Creates one band float image
* @(#) page 78 PIETGEN 1989 n = 12
* @(#) Usage
* @(#)
* @(#) int im_gaussnoise(image, xsize, ysize, mean, sigma)
* @(#) IMAGE *image;
* @(#) int xsize, ysize;
* @(#) double mean, sigma;
* @(#)
* @(#) Returns 0 on success and -1 on error
* *
* Copyright 1990, N. Dessipris. * Copyright 1990, N. Dessipris.
* *
@ -22,10 +11,13 @@
* - declaration for drand48() added * - declaration for drand48() added
* - partialised, adapting im_black() * - partialised, adapting im_black()
* 23/10/98 JC * 23/10/98 JC
* - drand48() chaged to random() for poartability * - drand48() chaged to random() for portability
* 21/10/02 JC * 21/10/02 JC
* - tries rand() if random() is not available * - tries rand() if random() is not available
* - uses RAND_MAX, d'oh * - uses RAND_MAX, d'oh
* 29/1/10
* - cleanups
* - gtkdoc
*/ */
/* /*
@ -111,34 +103,38 @@ gnoise_gen( REGION *or, void *seq, void *a, void *b )
return( 0 ); return( 0 );
} }
/* Make a one band float image of gaussian noise. /**
* im_gaussnoise:
* @out: output #IMAGE
* @x: output width
* @y: output height
* @mean: average value in output
* @sigma: standard deviation in output
*
* Make a one band float image of gaussian noise with the specified
* distribution. The noise distribution is created by averaging 12 random
* numbers with the appropriate weights.
*
* See also: im_make_xy(), im_text(), im_black().
*
* Returns: 0 on success, -1 on error
*/ */
int int
im_gaussnoise( IMAGE *out, int x, int y, double mean, double sigma ) im_gaussnoise( IMAGE *out, int x, int y, double mean, double sigma )
{ {
GnoiseInfo *gin; GnoiseInfo *gin;
/* Check parameters. if( x <= 0 || y <= 0 ) {
*/
if( x < 0 || y < 0 ) {
im_error( "im_gaussnoise", "%s", _( "bad parameter" ) ); im_error( "im_gaussnoise", "%s", _( "bad parameter" ) );
return( -1 ); return( -1 );
} }
/* Check descriptor.
*/
if( im_poutcheck( out ) ) if( im_poutcheck( out ) )
return( -1 ); return( -1 );
/* Set fields.
*/
im_initdesc( out, im_initdesc( out,
x, y, 1, x, y, 1,
IM_BBITS_FLOAT, IM_BANDFMT_FLOAT, IM_CODING_NONE, IM_TYPE_B_W, IM_BBITS_FLOAT, IM_BANDFMT_FLOAT, IM_CODING_NONE, IM_TYPE_B_W,
1.0, 1.0, 0, 0 ); 1.0, 1.0, 0, 0 );
/* Set hints - ANY is ok with us.
*/
if( im_demand_hint( out, IM_ANY, NULL ) ) if( im_demand_hint( out, IM_ANY, NULL ) )
return( -1 ); return( -1 );
@ -149,8 +145,6 @@ im_gaussnoise( IMAGE *out, int x, int y, double mean, double sigma )
gin->mean = mean; gin->mean = mean;
gin->sigma = sigma; gin->sigma = sigma;
/* Generate image.
*/
if( im_generate( out, NULL, gnoise_gen, NULL, gin, NULL ) ) if( im_generate( out, NULL, gnoise_gen, NULL, gin, NULL ) )
return( -1 ); return( -1 );