/* @(#) Filter functions * &(#) va_alist is a series of double variables * @(#) * @(#) Used to filter image in in the frequency domain, writes * @(#) the result in image out * @(#) * @(#) int im_flt_image_freq( in, out, flag, num_args, va_alist ) * @(#) IMAGE *in, *out; * @(#) enum mask_type flag; * @(#) int num_args; * @(#) * @(#) Returns 0 on success and -1 on error * @(#) * @(#) Creates a filter mask used for filtering in the frequency domain * @(#) The resultant mask is held by image * @(#) * @(#) int im_create_fmask(image, xsize, ysize, flag, num_args, va_alist) * @(#) IMAGE *image; * @(#) int xsize, ysize; * @(#) enum mask_type flag; * @(#) int num_args; * @(#) * @(#) Returns 0 on success and -1 on error * @(#) * @(#) Creates a filter mask used for filtering in the frequency domain * @(#) The resultant mask is held by image * @(#) Function im_freq_mask() differs from im_create_fmask() in the last * @(#) argument only: the latter accepts a va_dcl whereas the former * @(#) accepts a va_list pointer pointing to the read arguments of va_dcl * @(#) * @(#) int im_freq_mask(image, xs, ys, flag, num_args, ap) * @(#) IMAGE *image; * @(#) int xs, ys; * @(#) enum mask_type flag; * @(#) int num_args; * @(#) va_list ap; * @(#) * @(#) Returns 0 on success and -1 on error * @(#) * Copyright: N. Dessipris 1991, * Written on: Nov 1991 * Updated on: Dec 1991 * 20/9/95 JC * - modernised */ /* 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 #endif /*HAVE_CONFIG_H*/ #include #include #include #include #include #include #ifdef WITH_DMALLOC #include #endif /*WITH_DMALLOC*/ /* Create the final mask by copying the 1/4 of the mask held by coeff * The final mask is written onto image on a line by line basis * The buffer coeff should hold (xsize/2+1)*(ysize/2+1) elms * The created mask is not rotated; so the center is at (0, 0) */ static int copy_quarter( IMAGE *out, float *coeff_s ) { float *line, *cpline; float *coeff, *cpcoeff; int x, y; int hxsplus1; if( !(line = IM_ARRAY( out, out->Xsize, float )) ) return( -1 ); hxsplus1 = out->Xsize/2 + 1; coeff = coeff_s; for( y = 0; y < out->Ysize/2; y++ ) { cpline = line; cpcoeff = coeff; coeff += hxsplus1; for( x = 0; x < out->Xsize/2; x++ ) *cpline++ = *cpcoeff++; for( x = out->Xsize/2; x < out->Xsize; x++ ) *cpline++ = *cpcoeff--; if( im_writeline( y, out, (PEL *) line ) ) return( -1 ); } for( y = out->Ysize/2; y < out->Ysize; y++ ) { cpline = line; cpcoeff = coeff; coeff -= hxsplus1; for( x = 0; x < out->Xsize/2; x++ ) *cpline++ = *cpcoeff++; for( x = out->Xsize/2; x < out->Xsize; x++ ) *cpline++ = *cpcoeff--; if( im_writeline( y, out, (PEL *) line ) ) return( -1 ); } return( 0 ); } /* Make a mask image. */ static int build_freq_mask( IMAGE *out, int xs, int ys, MaskType flag, va_list ap ) { float *coeff; extern float *im__create_quarter( IMAGE *, int, int, MaskType, va_list ); /* Check sizes and create one quarter of the final mask */ if( !im_ispoweroftwo( xs ) || !im_ispoweroftwo( ys ) ) { im_errormsg( "im_freq_mask: mask sizes power of 2 only" ); return( -1 ); } /* Create the output image. */ im_initdesc( out, xs, ys, 1, IM_BBITS_FLOAT, IM_BANDFMT_FLOAT, IM_CODING_NONE, IM_TYPE_B_W, 1.0, 1.0, 0, 0 ); if( im_setupout( out ) ) return( -1 ); switch( flag ) { case MASK_IDEAL_HIGHPASS: case MASK_IDEAL_LOWPASS: case MASK_BUTTERWORTH_HIGHPASS: case MASK_BUTTERWORTH_LOWPASS: case MASK_GAUSS_HIGHPASS: case MASK_GAUSS_LOWPASS: case MASK_IDEAL_RINGPASS: case MASK_IDEAL_RINGREJECT: case MASK_BUTTERWORTH_RINGPASS: case MASK_BUTTERWORTH_RINGREJECT: case MASK_GAUSS_RINGPASS: case MASK_GAUSS_RINGREJECT: case MASK_FRACTAL_FLT: /* All these are created as a quarter and duplicated. */ if( !(coeff = im__create_quarter( out, xs, ys, flag, ap )) || copy_quarter( out, coeff ) ) return( -1 ); break; case MASK_IDEAL_BANDPASS: case MASK_IDEAL_BANDREJECT: case MASK_BUTTERWORTH_BANDPASS: case MASK_BUTTERWORTH_BANDREJECT: case MASK_GAUSS_BANDPASS: case MASK_GAUSS_BANDREJECT: /* Created all in one go. */ if( im__fmaskcir( out, flag, ap ) ) return( -1 ); break; default: im_errormsg( "im_freq_mask: unimplemented mask type" ); return( -1 ); } return( 0 ); } /* Create a mask, and filter an image with it. */ int im_flt_image_freq( IMAGE *in, IMAGE *out, MaskType flag, ... ) { IMAGE *mask = im_open_local( out, "tempmask", "p" ); va_list ap; if( !mask ) return( -1 ); /* Generate mask. */ va_start( ap, flag ); if( build_freq_mask( mask, in->Xsize, in->Ysize, flag, ap ) ) return( -1 ); va_end( ap ); if( im_freqflt( in, mask, out ) ) return( -1 ); return( 0 ); } /* Create a filter mask. */ int im_create_fmask( IMAGE *out, int xsize, int ysize, MaskType flag, ... ) { va_list ap; va_start( ap, flag ); if( build_freq_mask( out, xsize, ysize, flag, ap ) ) return( -1 ); va_end( ap ); return( 0 ); }