| /* im_bandmean.c |
| * |
| * Author: Simon Goodall |
| * Written on: 17/7/07 |
| * 17/7/07 JC |
| * - hacked about a bit |
| * 18/8/09 |
| * - gtkdoc |
| * - get rid of the complex case, just double the width |
| */ |
| |
| /* |
| |
| 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 <assert.h> |
| |
| #include <vips/vips.h> |
| #include <vips/internal.h> |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| /* Int types. Round, keep sum in a larger variable. |
| */ |
| #define ILOOP( TYPE, STYPE ) { \ |
| TYPE *p1 = (TYPE *) p; \ |
| TYPE *q1 = (TYPE *) q; \ |
| \ |
| for( i = 0; i < sz; i++ ) { \ |
| STYPE sum; \ |
| \ |
| sum = 0; \ |
| for( j = 0; j < b; j++ ) \ |
| sum += p1[j]; \ |
| q1[i] = sum > 0 ? (sum + b / 2) / b : (sum - b / 2) / b; \ |
| p1 += b; \ |
| } \ |
| } |
| |
| /* Float loop. No rounding, sum in same container. |
| */ |
| #define FLOOP( TYPE ) { \ |
| TYPE *p1 = (TYPE *) p; \ |
| TYPE *q1 = (TYPE *) q; \ |
| \ |
| for( i = 0; i < sz; i++ ) { \ |
| TYPE sum; \ |
| \ |
| sum = 0; \ |
| for( j = 0; j < b; j++ ) \ |
| sum += p1[j]; \ |
| q1[i] = sum / b; \ |
| p1 += b; \ |
| } \ |
| } |
| |
| static void |
| bandmean_buffer( PEL *p, PEL *q, int n, IMAGE *in ) |
| { |
| /* Complex just doubles the size. |
| */ |
| const int sz = n * (vips_bandfmt_iscomplex( in->BandFmt ) ? 2 : 1); |
| const int b = in->Bands; |
| |
| int i, j; |
| |
| switch( in->BandFmt ) { |
| case IM_BANDFMT_CHAR: ILOOP( signed char, int ); break; |
| case IM_BANDFMT_UCHAR: ILOOP( unsigned char, unsigned int ); break; |
| case IM_BANDFMT_SHORT: ILOOP( signed short, int ); break; |
| case IM_BANDFMT_USHORT: ILOOP( unsigned short, unsigned int ); break; |
| case IM_BANDFMT_INT: ILOOP( signed int, int ); break; |
| case IM_BANDFMT_UINT: ILOOP( unsigned int, unsigned int ); break; |
| case IM_BANDFMT_FLOAT: FLOOP( float ); break; |
| case IM_BANDFMT_DOUBLE: FLOOP( double ); break; |
| case IM_BANDFMT_COMPLEX:FLOOP( float ); break; |
| case IM_BANDFMT_DPCOMPLEX:FLOOP( double ); break; |
| |
| default: |
| assert( 0 ); |
| } |
| } |
| |
| /** |
| * im_bandmean: |
| * @in: input #IMAGE |
| * @out: output #IMAGE |
| * |
| * im_bandmean() writes a one-band image where each pixel is the average of |
| * the bands for that pixel in the input image. The output band format is |
| * the same as the input band format. Integer types use round-to-nearest |
| * averaging. |
| * |
| * See also: im_add(), im_avg(), im_recomb() |
| * |
| * Returns: 0 on success, -1 on error |
| */ |
| int |
| im_bandmean( IMAGE *in, IMAGE *out ) |
| { |
| /* Check input params |
| */ |
| if( in->Bands == 1 ) |
| return( im_copy( in, out ) ); |
| if( im_check_uncoded( "im_bandmean", in ) ) |
| return( -1 ); |
| |
| /* Prepare output image. |
| */ |
| if( im_cp_desc( out, in ) ) |
| return( -1 ); |
| out->Bands = 1; |
| out->Type = IM_TYPE_B_W; |
| |
| /* And process! |
| */ |
| if( im_wrapone( in, out, |
| (im_wrapone_fn) bandmean_buffer, in, NULL ) ) |
| return( -1 ); |
| |
| return( 0 ); |
| } |
| |