| /* @(#) creates a sinewave with horfreq cycles per horizontal direction and |
| * @(#) verfreq cycles per vertical direction |
| * @(#) If horfreq and verfreq are integers the resultant image is periodical |
| * @(#) and therfore the Fourier transform doesnot present spikes |
| * @(#) Image should have been set by a call to im_setbuf() or im_openout() |
| * @(#) |
| * @(#) Usage: int im_sines(image, xsize, ysize, horfreq, verfreq) |
| * @(#) IMAGE *image; |
| * @(#) int xsize, ysize; |
| * @(#) double horfreq, verfreq; |
| * @(#) |
| * @(#) Returns 0 on success and -1 on error |
| * @(#) |
| * |
| * Copyright: 1990, N. Dessipris. |
| * |
| * Author: Nicos Dessipris |
| * Written on: 02/02/1990 |
| * Modified on: |
| * 22/7/93 JC |
| * - externs removed |
| * - im_outcheck() added |
| */ |
| |
| /* |
| |
| 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 <stdlib.h> |
| #include <math.h> |
| |
| #include <vips/vips.h> |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| int |
| im_sines( IMAGE *image, int xsize, int ysize, double horfreq, double verfreq ) |
| { |
| int x, y; |
| float *line, *cpline; |
| int size; |
| double cons, factor; |
| double theta_rad, costheta, sintheta, ysintheta; |
| |
| /* Check input args */ |
| if( im_outcheck( image ) ) |
| return( -1 ); |
| if ( xsize <= 0 || ysize <= 0 ) { |
| im_error( "im_sines", "%s", _( "wrong sizes") ); |
| return(-1); } |
| |
| /* Set now image properly */ |
| im_initdesc(image, xsize, ysize, 1, IM_BBITS_FLOAT, IM_BANDFMT_FLOAT, |
| IM_CODING_NONE, IM_TYPE_B_W, 1.0, 1.0, 0, 0); |
| |
| /* Set up image checking whether the output is a buffer or a file */ |
| if (im_setupout( image ) == -1 ) |
| return( -1 ); |
| /* Create data */ |
| size = image->Xsize; |
| if ( (line=(float *)calloc((unsigned)size, sizeof(float))) == NULL ) { |
| im_error( "im_sines", "%s", _( "calloc failed") ); |
| return(-1); } |
| |
| /* make angle in rad */ |
| if (horfreq == 0) |
| theta_rad = IM_PI/2.0; |
| else |
| theta_rad = atan(verfreq/horfreq); |
| costheta = cos(theta_rad); sintheta = sin(theta_rad); |
| factor = sqrt ((double)(horfreq*horfreq + verfreq*verfreq)); |
| cons = factor * IM_PI * 2.0/(double)image->Xsize; |
| /* There is a bug (rounding error ?) for horfreq=0, |
| *so do this calculation independantly */ |
| if ( horfreq != 0 ) |
| { |
| for (y=0; y<image->Ysize; y++) |
| { |
| ysintheta = y * sintheta; |
| cpline = line; |
| for (x=0; x<image->Xsize; x++) |
| *cpline++ = |
| (float)(cos(cons*(x*costheta-ysintheta))); |
| if ( im_writeline( y, image, (PEL *)line ) == -1 ) |
| { |
| free ( (char *)line ); |
| return( -1 ); |
| } |
| } |
| } |
| else |
| { |
| for (y=0; y<image->Ysize; y++) |
| { |
| cpline = line; |
| ysintheta = cos (- cons * y * sintheta); |
| for (x=0; x<image->Xsize; x++) |
| *cpline++ = (float)ysintheta; |
| if ( im_writeline( y, image, (PEL *)line ) == -1 ) |
| { |
| free ( (char *)line ); |
| return( -1 ); |
| } |
| } |
| } |
| free ( (char *)line ); |
| return(0); |
| } |