/**
* im_tone_map:
* @in: input image
* @out: output image
* @lut: look-up table
*
* Map the first channel of @in through @lut. If @in is IM_CODING_LABQ, unpack
* to LABS, map L and then repack.
*
* @in should be a LABS or LABQ image for this to work
* sensibly.
*
* See also: im_maplut().
*
* Returns: 0 on success, -1 on error
*/
int
im_tone_map( IMAGE *in, IMAGE *out, IMAGE *lut )
{
IMAGE *t[8];
if( im_check_hist( "im_tone_map", lut ) ||
im_open_local_array( out, t, 8, "im_tone_map", "p" ) )
return( -1 );
/* If in is IM_CODING_LABQ, unpack.
*/
if( in->Coding == IM_CODING_LABQ ) {
if( im_LabQ2LabS( in, t[0] ) )
return( -1 );
}
else
t[0] = in;
/* Split into bands.
*/
if( im_extract_band( t[0], t[1], 0 ) )
return( -1 );
if( t[0]->Bands > 1 ) {
if( im_extract_bands( t[0], t[2], 1, t[0]->Bands - 1 ) )
return( -1 );
}
/* Map L.
*/
if( im_maplut( t[1], t[3], lut ) )
return( -1 );
/* Recombine bands.
*/
if( t[0]->Bands > 1 ) {
if( im_bandjoin( t[3], t[2], t[4] ) )
return( -1 );
}
else
t[4] = t[3];
/* If input was LabQ, repack.
*/
if( in->Coding == IM_CODING_LABQ ) {
if( im_LabS2LabQ( t[4], t[5] ) )
return( -1 );
}
else
t[5] = t[4];
return( im_copy( t[4], out ) );
}
/**
* im_heq:
* @in: input image
* @out: output image
* @bandno: band to equalise
*
* Histogram-equalise @in. Equalise using band @bandno, or if @bandno is -1,
* equalise all bands.
*
* See also: im_lhisteq(), im_histgr(), im_histeq().
*
* Returns: 0 on success, -1 on error
*/
int
im_heq( IMAGE *in, IMAGE *out, int bandno )
{
IMAGE *t[2];
if( im_open_local_array( out, t, 2, "im_heq", "p" ) ||
im_histgr( in, t[0], bandno ) ||
im_histeq( t[0], t[1] ) ||
im_maplut( in, out, t[1] ) )
return( -1 );
return( 0 );
}
/**
* im_hsp:
* @in: input image
* @ref: reference histogram
* @out: output image
*
* Maps image @in to image @out, adjusting the histogram to match image @ref.
* Both images should have the same number of bands.
*
* See also: im_histspec(), im_histgr().
*
* Returns: 0 on success, -1 on error
*/
int
im_hsp( IMAGE *in, IMAGE *ref, IMAGE *out )
{
IMAGE *t[3];
if( im_open_local_array( out, t, 3, "im_hsp", "p" ) ||
im_histgr( in, t[0], -1 ) ||
im_histgr( ref, t[1], -1 ) ||
im_histspec( t[0], t[1], t[2] ) ||
im_maplut( in, out, t[2] ) )
return( -1 );
return( 0 );
}
int
im_heq( IMAGE *in, IMAGE *out, int bandno )
{
IMAGE *t1 = im_open_local( out, "im_heq:1", "p" );
IMAGE *t2 = im_open_local( out, "im_heq:2", "p" );
if( !t1 || !t2 ||
im_histgr( in, t1, bandno ) ||
im_histeq( t1, t2 ) ||
im_maplut( in, out, t2 ) )
return( -1 );
return( 0 );
}
/**
* im_gammacorrect:
* @in: input image
* @out: output image
* @exponent: gamma factor
*
* Gamma-correct an 8- or 16-bit unsigned image with a lookup table. The
* output format is the same as the input format.
*
* See also: im_identity(), im_powtra(), im_maplut()
*
* Returns: 0 on success, -1 on error
*/
int
im_gammacorrect( IMAGE *in, IMAGE *out, double exponent )
{
IMAGE *t[4];
double mx1, mx2;
if( im_open_local_array( out, t, 4, "im_gammacorrect", "p" ) ||
im_check_u8or16( "im_gammacorrect", in ) ||
im_piocheck( in, out ) ||
(in->BandFmt == IM_BANDFMT_UCHAR ?
im_identity( t[0], 1 ) :
im_identity_ushort( t[0], 1, 65536 )) ||
im_powtra( t[0], t[1], exponent ) ||
im_max( t[0], &mx1 ) ||
im_max( t[1], &mx2 ) ||
im_lintra( mx1 / mx2, t[1], 0, t[2] ) ||
im_clip2fmt( t[2], t[3], in->BandFmt ) ||
im_maplut( in, out, t[3] ) )
return( -1 );
return( 0 );
}
