int
im_freqflt( IMAGE *in, IMAGE *mask, IMAGE *out )
{
IMAGE *dummy;
/* Placeholder for memory free.
*/
if( !(dummy = im_open( "memory-1", "p" )) )
return( -1 );
if( im_iscomplex( in ) ) {
/* Easy case! Assume it has already been transformed.
*/
IMAGE *t1 = im_open_local( dummy, "im_freqflt-1", "p" );
if( !t1 ||
im_multiply( in, mask, t1 ) ||
im_invfftr( t1, out ) ) {
im_close( dummy );
return( -1 );
}
}
else {
/* Harder - fft first, then mult, then force back to start
* type.
*
* Optimisation: output of im_invfft() is float buffer, we
* will usually chagetype to char, so rather than keeping a
* large float buffer and partial to char from that, do
* changetype to a memory buffer, and copy to out from that.
*/
IMAGE *t[3];
IMAGE *t3;
if( im_open_local_array( dummy, t, 3, "im_freqflt-1", "p" ) ||
!(t3 = im_open_local( out, "im_freqflt-3", "t" )) ||
im_fwfft( in, t[0] ) ||
im_multiply( t[0], mask, t[1] ) ||
im_invfftr( t[1], t[2] ) ||
im_clip2fmt( t[2], t3, in->BandFmt ) ||
im_copy( t3, out ) ) {
im_close( dummy );
return( -1 );
}
}
im_close( dummy );
return( 0 );
}
/**
* im_cmulnorm
* @in1: input #IMAGE 1
* @in2: input #IMAGE 2
* @out: output #IMAGE
*
* im_cmulnorm() multiplies two complex images. The complex output is
* normalised to 1 by dividing both the real and the imaginary part of each
* pel with the norm. This is useful for phase correlation.
*
* This operation used to be important, but now simply calls im_multiply()
* then im_sign().
*
* See also: im_multiply(), im_sign().
*
* Returns: 0 on success, -1 on error
*/
int
im_cmulnorm( IMAGE *in1, IMAGE *in2, IMAGE *out )
{
IMAGE *t1;
if( !(t1 = im_open_local( out, "im_cmulnorm:1", "p" )) ||
im_multiply( in1, in2, t1 ) ||
im_sign( t1, out ) )
return( -1 );
return( 0 );
}
