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invert works for all formats

This commit is contained in:
John Cupitt 2011-10-31 09:04:59 +00:00
parent b4531ff24b
commit c2efba5162
2 changed files with 55 additions and 27 deletions
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9
TODO
View File

@ -1,17 +1,8 @@
- invert is useless. make it work for all types at least
- lintra_vec next
- try:
$ vips insert Gugg_coloured.jpg x.jpg x.v 100 100 --expand --background "1 2 3"

73
libvips/arithmetic/invert.c
View File

@ -66,16 +66,11 @@
* @in: input #VipsImage
* @out: output #VipsImage
*
* this operation calculates (255 - @in).
* The operation works on uchar images only. The input can have any
* number of channels.
* For unsigned formats, this operation calculates (max - @in), eg. (255 -
* @in) for uchar. For signed and float formats, this operation calculates (-1
* * @in).
*
* This is not a generally useful operation -- it is included as an example of
* a very simple operation.
* See im_exptra() for an example of a VIPS function which can process
* any input image type.
*
* See also: im_exptra(), im_lintra().
* See also: im_lintra().
*
* Returns: 0 on success, -1 on error
*/
@ -85,17 +80,60 @@ typedef VipsUnaryClass VipsInvertClass;
G_DEFINE_TYPE( VipsInvert, vips_invert, VIPS_TYPE_UNARY );
#define LOOP( TYPE, L ) { \
TYPE *p = (TYPE *) in[0]; \
TYPE *q = (TYPE *) out; \
\
for( x = 0; x < sz; x++ ) \
q[x] = (L) - p[x]; \
}
#define LOOPN( TYPE ) { \
TYPE *p = (TYPE *) in[0]; \
TYPE *q = (TYPE *) out; \
\
for( x = 0; x < sz; x++ ) \
q[x] = -1 * p[x]; \
}
static void
vips_invert_buffer( VipsArithmetic *arithmetic, PEL *out, PEL **in, int width )
{
VipsImage *im = arithmetic->ready[0];
PEL *p = in[0];
int ne = width * im->Bands;
/* Complex just doubles the size.
*/
const int sz = width * vips_image_get_bands( im ) *
(vips_band_format_iscomplex( vips_image_get_format( im ) ) ?
2 : 1);
int x;
for( x = 0; x < ne; x++ )
out[x] = 255 - p[x];
switch( vips_image_get_format( im ) ) {
case VIPS_FORMAT_UCHAR:
LOOP( unsigned char, UCHAR_MAX ); break;
case VIPS_FORMAT_CHAR:
LOOPN( signed char ); break;
case VIPS_FORMAT_USHORT:
LOOP( unsigned short, USHRT_MAX ); break;
case VIPS_FORMAT_SHORT:
LOOPN( signed short ); break;
case VIPS_FORMAT_UINT:
LOOP( unsigned int, UINT_MAX ); break;
case VIPS_FORMAT_INT:
LOOPN( signed int ); break;
case VIPS_FORMAT_FLOAT:
case VIPS_FORMAT_COMPLEX:
LOOPN( float ); break;
case VIPS_FORMAT_DOUBLE:
case VIPS_FORMAT_DPCOMPLEX:
LOOPN( double ); break;
default:
g_assert( 0 );
}
}
/* Save a bit of typing.
@ -111,12 +149,11 @@ vips_invert_buffer( VipsArithmetic *arithmetic, PEL *out, PEL **in, int width )
#define D VIPS_FORMAT_DOUBLE
#define DX VIPS_FORMAT_DPCOMPLEX
/* Type promotion for invertion. Sign and value preserving. Make sure these
* match the case statement in vips_invert_buffer() above.
/* Format doesn't change with invert.
*/
static const VipsBandFormat bandfmt_invert[10] = {
static const VipsBandFormat vips_bandfmt_invert[10] = {
/* UC C US S UI I F X D DX */
UC, UC, UC, UC, UC, UC, UC, UC, UC, UC
UC, C, US, S, UI, I, F, X, D, DX
};
static void
@ -128,7 +165,7 @@ vips_invert_class_init( VipsInvertClass *class )
object_class->nickname = "invert";
object_class->description = _( "invert an image" );
vips_arithmetic_set_format_table( aclass, bandfmt_invert );
vips_arithmetic_set_format_table( aclass, vips_bandfmt_invert );
aclass->process_line = vips_invert_buffer;
}