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add im_point()

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This commit is contained in:
John Cupitt 2009-09-09 08:54:10 +00:00
parent 94eaae68ef
commit ad6bb5d67f
5 changed files with 114 additions and 78 deletions
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1
ChangeLog
View File

@ -32,6 +32,7 @@
- im_maxpos()/im_minpos() are partial and work for complex
- im_max()/im_min() are now convenience functions
- im_maxpos_avg() handles complex and multi-band images
- added im_point(), rewrite im_point_bilinear() in terms of this
25/3/09 started 7.18.0
- revised version numbers

8
TODO
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@ -1,3 +1,11 @@
- try
$ vips im_point kylie110.jpg bilinear 0 0 0
(vips:8895): GLib-GObject-WARNING **: invalid unclassed pointer in cast to
`VipsInterpolate'
Segmentation fault
how odd
- im_maxpos_vec needs gtkdoc

36
libvips/arithmetic/arith_dispatch.c
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@ -319,6 +319,41 @@ static im_function avg_desc = {
image_in_num_out /* Arg list */
};
/* Args to im_point.
*/
static im_arg_desc point_args[] = {
IM_INPUT_IMAGE( "in" ),
IM_INPUT_INTERPOLATE( "interpolate" ),
IM_INPUT_DOUBLE( "x" ),
IM_INPUT_DOUBLE( "y" ),
IM_INPUT_INT( "band" ),
IM_OUTPUT_DOUBLE( "out" )
};
/* Call im_point via arg vector.
*/
static int
point_vec( im_object *argv )
{
VipsInterpolate *interpolate = VIPS_INTERPOLATE( argv[2] );
double x = *((double *) argv[2]);
double y = *((double *) argv[3]);
int band = *((double *) argv[4]);
return( im_point( argv[0], interpolate, x, y, band, argv[5] ) );
}
/* Description of im_point.
*/
static im_function point_desc = {
"im_point",
"interpolate value at single point",
IM_FN_PIO,
point_vec,
IM_NUMBER( point_args ),
point_args
};
/* Args to im_point_bilinear.
*/
static im_arg_desc point_bilinear_args[] = {
@ -1356,6 +1391,7 @@ static im_function *arith_list[] = {
&asintra_desc,
&atantra_desc,
&avg_desc,
&point_desc,
&point_bilinear_desc,
&bandmean_desc,
&ceil_desc,

143
libvips/arithmetic/im_point_bilinear.c
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@ -1,20 +1,13 @@
/* @(#) Find the value at (x,y) in given band of image.
* @(#) Use bilinear interpolation if x or y are non-integral.
* @(#)
* @(#) int im_maxpos_vec(
* @(#) IMAGE *im,
* @(#) double x,
* @(#) double y,
* @(#) int band,
* @(#) double *val
* @(#) );
* @(#)
/* im_point_bilinear.c
*
* Copyright: 2006, The Nottingham Trent University
*
* Author: Tom Vajzovic
*
* Written on: 2006-09-26
*
* 9/9/09
* - rewrite in terms of im_affinei() and im_avg()
*/
/*
@ -43,85 +36,81 @@
*/
/** HEADERS **/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_CONFIG_H */
#include <vips/intl.h>
#include <math.h>
#include <vips/vips.h>
#include <vips/r_access.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC */
/**
* im_point:
* @im: image to read from
* @interpolate: interpolator to sample points with
* @x: x position to interpolate
* @y: y position to interpolate
* @band: band to read
* @out: return interpolated value
*
* Find the value at (@x, @y) in given band of image.
* Use bilinear interpolation if @x or @y are non-integral.
*
* See also: im_avg(), #VipsInterpolate
*
* Returns: 0 on success, -1 on error
*/
int
im_point( IMAGE *im, VipsInterpolate *interpolate,
double x, double y, int band, double *out )
{
IMAGE *t[2];
/** EXPORTED FUNCTION **/
if( band >= im->Bands ||
x < 0.0 || y < 0.0 ||
x > im->Xsize || y > im->Ysize ) {
im_error( "im_point_bilinear", "%s",
_( "coords outside image" ) );
return( -1 );
}
int im_point_bilinear( IMAGE *im, double x, double y, int band, double *val ){
#define FUNCTION_NAME "im_point_bilinear"
if( im_open_local_array( im, t, 2, "im_point_bilinear", "p" ) ||
im_extract_band( im, t[0], band ) ||
im_affinei( t[0], t[1],
interpolate,
1, 0, 0, 1,
x - floor( x ), y - floor( y ),
floor( x ), floor( y ), 1, 1 ) ||
im_avg( t[1], out ) )
return( -1 );
double x_frac= x - (int) x;
double y_frac= y - (int) y;
Rect need= { x, y, ( x_frac ? 2 : 1 ), ( y_frac ? 2 : 1 ) };
REGION *reg;
if( im_pincheck( im ) )
return -1;
if( im-> Coding ){
im_error( FUNCTION_NAME, "%s", _("uncoded images only") );
return -1;
}
if( !( im_isint( im ) || im_isfloat( im ) ) ){
im_error( FUNCTION_NAME, "%s", _("scalar images only") );
return -1;
}
if( band >= im-> Bands || x < 0.0 || y < 0.0 || x > im-> Xsize || y > im-> Ysize ){
im_error( FUNCTION_NAME, "%s", _("coords outside image") );
return -1;
}
if( ! val ){
im_error( FUNCTION_NAME, "%s", _("invalid arguments") );
return -1;
}
reg= im_region_create( im );
if( ! reg || im_prepare( reg, &need ) )
return -1;
if( ! im_rect_includesrect( &reg-> valid, &need ) ){
im_error( FUNCTION_NAME, "%s", _("coords outside image") );
im_region_free( reg );
return -1;
}
if( x_frac )
if( y_frac )
*val= x_frac * y_frac * (double) IM_REGION_VALUE( reg, ((int)x + 1), ((int)y + 1), band )
+ x_frac * ( 1.0 - y_frac ) * (double) IM_REGION_VALUE( reg, ((int)x + 1), (int)y , band )
+ ( 1.0 - x_frac ) * y_frac * (double) IM_REGION_VALUE( reg, (int)x, ((int)y + 1), band )
+ ( 1.0 - x_frac ) * ( 1.0 - y_frac ) * (double) IM_REGION_VALUE( reg, (int)x, (int)y , band );
else
*val= x_frac * IM_REGION_VALUE( reg, ((int)x + 1), (int)y, band )
+ ( 1.0 - x_frac ) * IM_REGION_VALUE( reg, (int)x, (int)y, band );
else
if( y_frac )
*val= y_frac * IM_REGION_VALUE( reg, (int)x, ((int)y + 1), band )
+ ( 1.0 - y_frac ) * IM_REGION_VALUE( reg, (int)x, (int)y , band );
else
*val= IM_REGION_VALUE( reg, (int)x, (int)y, band );
im_region_free( reg );
return 0;
#undef FUNCTION_NAME
return( 0 );
}
/**
* im_point_bilinear:
* @im: image to read from
* @x: x position to interpolate
* @y: y position to interpolate
* @band: band to read
* @out: return interpolated value
*
* Find the value at (@x,@y) in given band of image.
* Use bilinear interpolation if @x or @y are non-integral.
*
* See also: im_avg(), im_point().
*
* Returns: 0 on success, -1 on error
*/
int
im_point_bilinear( IMAGE *im, double x, double y, int band, double *out )
{
return( im_point( im, vips_interpolate_bilinear_static(),
x, y, band, out ) );
}

4
libvips/include/vips/arithmetic.h
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@ -60,7 +60,9 @@ int im_lintra( double a, IMAGE *in, double b, IMAGE *out );
int im_lintra_vec( int n, double *a, IMAGE *in, double *b, IMAGE *out );
int im_multiply( IMAGE *in1, IMAGE *in2, IMAGE *out );
int im_divide( IMAGE *in1, IMAGE *in2, IMAGE *out );
int im_point_bilinear( IMAGE *im, double x, double y, int band, double *val );
int im_point( IMAGE *im, VipsInterpolate *interpolate,
double x, double y, int band, double *out );
int im_point_bilinear( IMAGE *im, double x, double y, int band, double *out );
int im_powtra( IMAGE *in, IMAGE *out, double e );
int im_powtra_vec( IMAGE *in, IMAGE *out, int n, double *e );
int im_exptra( IMAGE *in, IMAGE *out );