| /* @(#) Functions which takes as input a valid image and filters it |
| * @(#) in the fourier domain with the filter mask |
| * @(#) Input can have any format ; output is the same as input |
| * @(#) imin can be char uchar, short, ushort, int, uint, float, double |
| * @(#) or complex float; result is the same as input, clipped if necessary. |
| * @(#) mask can have any format but the sizes of input and mask are equal |
| * @(#) The function performs float fft and if the input is not complex float |
| * @(#) the output is casted to the type of input according to im_clip2..() |
| * @(#) Since buffer images are involved the size, is restricted to 512x512 |
| * @(#) for the SUN4 SPARC workstation |
| * @(#) |
| * @(#) int im_freqflt(imin, mask, imout) |
| * @(#) IMAGE *imin, *mask, *imout; |
| * @(#) |
| * @(#) Returns 0 on success and -1 on error |
| * |
| * Copyright: 1990, N. Dessipris. |
| * |
| * Author: Nicos Dessipris |
| * Written on: 02/05/1990 |
| * Modified on : 08/03/1991 |
| * 16/6/93 J.Cupitt |
| * - im_multiply() called, rather than im_cmultim() |
| * 27/10/93 JC |
| * - im_clip2*() called, rather than im_any2*() |
| * 20/9/95 JC |
| * - rewritten |
| * 10/9/98 JC |
| * - frees memory more quickly |
| * 4/3/03 JC |
| * - use im_invfftr() to get real back for speedup |
| */ |
| |
| /* |
| |
| This file is part of VIPS. |
| |
| VIPS is free software; you can redistribute it and/or modify |
| it under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| */ |
| |
| /* |
| |
| These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk |
| |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif /*HAVE_CONFIG_H*/ |
| #include <vips/intl.h> |
| |
| #include <stdio.h> |
| #include <math.h> |
| |
| #include <vips/vips.h> |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| /** |
| * im_freqflt: |
| * @in: input image |
| * @mask: mask image |
| * @out: output image |
| * |
| * Filter an image in Fourier space. |
| * |
| * @in is transformed to Fourier space, multipled with the mask image, then |
| * transformed back to real space. If @in is already a complex image, just |
| * multiply then inverse transform. |
| * |
| * See also: im_invfftr(), im_create_fmask(). |
| * |
| * Returns: 0 on success, -1 on error. |
| */ |
| 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( vips_bandfmt_iscomplex( in->BandFmt ) ) { |
| /* 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 ); |
| } |
| |