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fix hist_norm range

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the cast change broke hist_norm
This commit is contained in:
John Cupitt 2020-05-04 17:04:37 +01:00
parent 29d9fcb0c8
commit 8281416ca4
1 changed files with 8 additions and 7 deletions
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15
libvips/histogram/hist_norm.c
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@ -77,7 +77,7 @@ vips_hist_norm_build( VipsObject *object )
VipsHistNorm *norm = (VipsHistNorm *) object;
VipsImage **t = (VipsImage **) vips_object_local_array( object, 3 );
guint64 px;
guint64 new_max;
int bands;
double *a, *b;
int y;
@ -95,13 +95,13 @@ vips_hist_norm_build( VipsObject *object )
/* Scale each channel by px / channel max
*/
px = VIPS_IMAGE_N_PELS( norm->in );
new_max = VIPS_IMAGE_N_PELS( norm->in ) - 1;
bands = norm->in->Bands;
if( !(a = VIPS_ARRAY( object, bands, double )) ||
!(b = VIPS_ARRAY( object, bands, double )) )
return( -1 );
for( y = 0; y < bands; y++ ) {
a[y] = px / *VIPS_MATRIX( t[0], 1, y + 1 );
a[y] = new_max / *VIPS_MATRIX( t[0], 1, y + 1 );
b[y] = 0;
}
@ -110,9 +110,9 @@ vips_hist_norm_build( VipsObject *object )
/* Make output format as small as we can.
*/
if( px <= 256 )
if( new_max <= 255 )
fmt = VIPS_FORMAT_UCHAR;
else if( px <= 65536 )
else if( new_max <= 65535 )
fmt = VIPS_FORMAT_USHORT;
else
fmt = VIPS_FORMAT_UINT;
@ -161,8 +161,9 @@ vips_hist_norm_init( VipsHistNorm *hist_norm )
* @out: (out): output image
* @...: %NULL-terminated list of optional named arguments
*
* Normalise histogram ... normalise range to make it square (ie. max ==
* number of elements). Normalise each band separately.
* Normalise histogram. The maximum of each band becomes equal to the maximum
* index, so for example the max for a uchar image becomes 255.
* Normalise each band separately.
*
* See also: vips_hist_cum().
*