int
im_extract( IMAGE *in, IMAGE *out, IMAGE_BOX *box )
{
if( box->chsel == -1 )
return( im_extract_areabands( in, out,
box->xstart, box->ystart, box->xsize, box->ysize,
0, in->Bands ) );
else
return( im_extract_areabands( in, out,
box->xstart, box->ystart, box->xsize, box->ysize,
box->chsel, 1 ) );
}
/* Call im_extract via arg vector.
*/
static int
extract_vec( im_object *argv )
{
int left = *((int *) argv[2]);
int top = *((int *) argv[3]);
int width = *((int *) argv[4]);
int height = *((int *) argv[5]);
int band = *((int *) argv[6]);
return( im_extract_areabands( argv[0], argv[1],
left, top, width, height, band, 1 ) );
}
/* Get the value of pixel (0, 0). Use this to init the min/max value for
* im_max()/im_stats()/etc.
*/
int
im__value( IMAGE *im, double *value )
{
IMAGE *t;
if( !(t = im_open( "im__value", "p" )) )
return( -1 );
if( im_extract_areabands( im, t, 0, 0, 1, 1, 0, 1 ) ||
im_avg( t, value ) ) {
im_close( t );
return( -1 );
}
im_close( t );
return( 0 );
}
/* Measure into array.
*/
static int
measure_patches( IMAGE *im, double *coeff,
int left, int top, int width, int height,
int u, int v, int *sel, int nsel )
{
IMAGE *tmp;
int patch;
int i, j;
int m, n;
double avg, dev;
int x, y, w, h;
/* How large are the patches we are to measure?
*/
double pw = (double) width / (double) u;
double ph = (double) height / (double) v;
/* Set up sub to be the size we need for a patch.
*/
w = (pw + 1) / 2;
h = (ph + 1) / 2;
/* Loop through sel, picking out areas to measure.
*/
for( j = 0, patch = 0; patch < nsel; patch++ ) {
/* Sanity check. Is the patch number sensible?
*/
if( sel[patch] <= 0 || sel[patch] > u * v ) {
im_error( "im_measure",
_( "patch %d is out of range" ),
sel[patch] );
return( 1 );
}
/* Patch coordinates.
*/
m = (sel[patch] - 1) % u;
n = (sel[patch] - 1) / u;
/* Move sub to correct position.
*/
x = left + m * pw + (pw + 2) / 4;
y = top + n * ph + (ph + 2) / 4;
/* Loop through bands.
*/
for( i = 0; i < im->Bands; i++, j++ ) {
/* Make temp buffer to extract to.
*/
if( !(tmp = im_open( "patch", "t" )) )
return( -1 );
/* Extract and measure.
*/
if( im_extract_areabands( im, tmp, x, y, w, h, i, 1 ) ||
im_avg( tmp, &avg ) ||
im_deviate( tmp, &dev ) ) {
im_close( tmp );
return( -1 );
}
im_close( tmp );
/* Is the deviation large compared with the average?
* This could be a clue that our parameters have
* caused us to miss the patch. Look out for averages
* <0, or averages near zero (can get these if use
* im_measure() on IM_TYPE_LAB images).
*/
if( dev * 5 > fabs( avg ) && fabs( avg ) > 3 )
im_warn( "im_measure",
_( "patch %d, band %d: "
"avg = %g, sdev = %g" ),
patch, i, avg, dev );
/* Save results.
*/
coeff[j] = avg;
}
}
return( 0 );
}