/* Normalise an image using the rules noted above.
*/
static int
normalise( IMAGE *in, IMAGE *out )
{
if( im_check_uncoded( "im_histplot", in ) ||
im_check_noncomplex( "im_histplot", in ) )
return( -1 );
if( vips_bandfmt_isuint( in->BandFmt ) ) {
if( im_copy( in, out ) )
return( -1 );
}
else if( vips_bandfmt_isint( in->BandFmt ) ) {
IMAGE *t1;
double min;
/* Move min up to 0.
*/
if( !(t1 = im_open_local( out, "im_histplot", "p" )) ||
im_min( in, &min ) ||
im_lintra( 1.0, in, -min, t1 ) )
return( -1 );
}
else {
/* Float image: scale min--max to 0--any. Output square
* graph.
*/
IMAGE *t1;
DOUBLEMASK *stats;
double min, max;
int any;
if( in->Xsize == 1 )
any = in->Ysize;
else
any = in->Xsize;
if( !(stats = im_stats( in )) )
return( -1 );
min = VIPS_MASK( stats, 0, 0 );
max = VIPS_MASK( stats, 1, 0 );
im_free_dmask( stats );
if( !(t1 = im_open_local( out, "im_histplot", "p" )) ||
im_lintra( any / (max - min), in,
-min * any / (max - min), out ) )
return( -1 );
}
return( 0 );
}
/**
* im_abs:
* @in: input #IMAGE
* @out: output #IMAGE
*
* This operation finds the absolute value of an image. It does a copy for
* unsigned integer types, negate for negative values in
* signed integer types, <function>fabs(3)</function> for
* float types, and calculate modulus for complex
* types.
*
* See also: im_exp10tra(), im_sign().
*
* Returns: 0 on success, -1 on error
*/
int
im_abs( IMAGE *in, IMAGE *out )
{
if( im_piocheck( in, out ) ||
im_check_uncoded( "im_abs", in ) )
return( -1 );
/* Is this one of the unsigned types? Degenerate to im_copy() if it
* is.
*/
if( vips_bandfmt_isuint( in->BandFmt ) )
return( im_copy( in, out ) );
/* Prepare output header. Output type == input type, except for
* complex.
*/
if( im_cp_desc( out, in ) )
return( -1 );
switch( in->BandFmt ) {
case IM_BANDFMT_CHAR:
case IM_BANDFMT_SHORT:
case IM_BANDFMT_INT:
case IM_BANDFMT_FLOAT:
case IM_BANDFMT_DOUBLE:
/* No action.
*/
break;
case IM_BANDFMT_COMPLEX:
out->BandFmt = IM_BANDFMT_FLOAT;
break;
case IM_BANDFMT_DPCOMPLEX:
out->BandFmt = IM_BANDFMT_DOUBLE;
break;
default:
im_error( "im_abs", "%s", _( "unknown input type" ) );
return( -1 );
}
/* Generate!
*/
if( im_wrapone( in, out,
(im_wrapone_fn) abs_gen, in, NULL ) )
return( -1 );
return( 0 );
}
/**
* im_zerox:
* @in: input image
* @out: output image
* @sign: detect positive or negative zero crossings
*
* im_zerox() detects the positive or negative zero crossings @in,
* depending on @sign. If @sign is -1, negative zero crossings are returned,
* if @sign is 1, positive zero crossings are returned.
*
* The output image is byte with zero crossing set to 255 and all other values
* set to zero. Input can have any number of channels, and be any non-complex
* type.
*
* See also: im_conv(), im_rot90.
*
* Returns: 0 on success, -1 on error
*/
int
im_zerox( IMAGE *in, IMAGE *out, int sign )
{
IMAGE *t1;
if( sign != -1 && sign != 1 ) {
im_error( "im_zerox", "%s", _( "flag not -1 or 1" ) );
return( -1 );
}
if( in->Xsize < 2 ) {
im_error( "im_zerox", "%s", _( "image too narrow" ) );
return( -1 );
}
if( !(t1 = im_open_local( out, "im_zerox" , "p" )) ||
im_piocheck( in, t1 ) ||
im_check_uncoded( "im_zerox", in ) ||
im_check_noncomplex( "im_zerox", in ) )
return( -1 );
if( vips_bandfmt_isuint( in->BandFmt ) )
/* Unsigned type, therefore there will be no zero-crossings.
*/
return( im_black( out, in->Xsize, in->Ysize, in->Bands ) );
/* Force output to be BYTE. Output is narrower than input by 1 pixel.
*/
if( im_cp_desc( t1, in ) )
return( -1 );
t1->BandFmt = IM_BANDFMT_UCHAR;
t1->Xsize -= 1;
/* Set hints - THINSTRIP is ok with us.
*/
if( im_demand_hint( t1, IM_THINSTRIP, NULL ) )
return( -1 );
/* Generate image.
*/
if( im_generate( t1, im_start_one, zerox_gen, im_stop_one,
in, GINT_TO_POINTER( sign ) ) )
return( -1 );
/* Now embed it in a larger image.
*/
if( im_embed( t1, out, 0, 0, 0, in->Xsize, in->Ysize ) )
return( -1 );
return( 0 );
}
/**
* im_msb:
* @in: input image
* @out: output image
*
* Turn any integer image to 8-bit unsigned char by discarding all but the most
* significant byte.
* Signed values are converted to unsigned by adding 128.
*
* This operator also works for LABQ coding.
*
* See also: im_msb_band().
*
* Returns: 0 on success, -1 on error
*/
int
im_msb( IMAGE *in, IMAGE *out )
{
Msb *msb;
im_wrapone_fn func;
if( in->Coding == IM_CODING_NONE &&
in->BandFmt == IM_BANDFMT_UCHAR )
return( im_copy( in, out ) );
if( im_piocheck( in, out ) ||
!(msb = IM_NEW( out, Msb )) )
return( -1 );
if( in->Coding == IM_CODING_NONE ) {
if( im_check_int( "im_msb", in ) )
return( -1 );
msb->width = IM_IMAGE_SIZEOF_ELEMENT( in );
msb->index = im_amiMSBfirst() ? 0 : msb->width - 1;
msb->repeat = in->Bands;
if( vips_bandfmt_isuint( in->BandFmt ) )
func = (im_wrapone_fn) byte_select;
else
func = (im_wrapone_fn) byte_select_flip;
}
else if( IM_CODING_LABQ == in->Coding )
func = (im_wrapone_fn) msb_labq;
else {
im_error( "im_msb", "%s", _( "unknown coding" ) );
return( -1 );
}
if( im_cp_desc( out, in ) )
return( -1 );
out->BandFmt = IM_BANDFMT_UCHAR;
out->Coding = IM_CODING_NONE;
return( im_wrapone( in, out, func, msb, NULL ) );
}
gboolean
im_isuint( IMAGE *im )
{
return( vips_bandfmt_isuint( im->BandFmt ) );
}
/**
* im_msb_band:
* @in: input image
* @out: output image
* @band: select this band
*
* Turn any integer image to a single-band 8-bit unsigned char by discarding
* all but the most significant byte from the selected band.
* Signed values are converted to unsigned by adding 128.
*
* This operator also works for LABQ coding.
*
* See also: im_msb_band().
*
* Returns: 0 on success, -1 on error
*/
int
im_msb_band( IMAGE *in, IMAGE *out, int band )
{
Msb *msb;
im_wrapone_fn func;
if( band < 0 ) {
im_error( "im_msb_band", "%s", _( "bad arguments" ) );
return( -1 );
}
if( im_piocheck( in, out ) ||
!(msb = IM_NEW( out, Msb )) )
return( -1 );
if( in->Coding == IM_CODING_NONE ) {
if( im_check_int( "im_msb_band", in ) )
return( -1 );
if( band >= in->Bands ) {
im_error( "im_msb_band", "%s",
_( "image does not have that many bands" ) );
return( -1 );
}
msb->width = IM_IMAGE_SIZEOF_ELEMENT( in );
msb->index = im_amiMSBfirst() ?
msb->width * band : msb->width * (band + 1) - 1;
msb->repeat = 1;
if( vips_bandfmt_isuint( in->BandFmt ) )
func = (im_wrapone_fn) byte_select;
else
func = (im_wrapone_fn) byte_select_flip;
}
else if( IM_CODING_LABQ == in->Coding ) {
if( band > 2 ) {
im_error( "im_msb_band", "%s",
_( "image does not have that many bands" ) );
return( -1 );
}
msb->width = 4;
msb->repeat = 1;
msb->index = band;
if( band )
func = (im_wrapone_fn) byte_select_flip;
else
func = (im_wrapone_fn) byte_select;
}
else {
im_error( "im_msb", "%s", _( "unknown coding" ) );
return( -1 );
}
if( im_cp_desc( out, in ) )
return( -1 );
out->BandFmt = IM_BANDFMT_UCHAR;
out->Coding = IM_CODING_NONE;
out->Bands = 1;
return( im_wrapone( in, out, func, msb, NULL ) );
}
