/* Divide two images * * Copyright: 1990, N. Dessipris. * * Author: Nicos Dessipris * Written on: 02/05/1990 * Modified on: * 29/4/93 JC * - now works for partial images * 1/7/93 JC * - adapted for partial v2 * - ANSIfied * 19/10/93 JC * - coredump-inducing bug in complex*complex fixed * 13/12/93 * - char * short bug fixed * 12/6/95 JC * - new im_multiply adapted to make new im_divide * 27/9/04 * - updated for 1 band $op n band image -> n band image case * 8/12/06 * - add liboil support * 18/8/08 * - revise upcasting system * - add gtkdoc comments * 31/7/10 * - remove liboil support * - avoid /0 * 6/11/11 * - rewrite as a class * 22/2/12 * - avoid /0 for complex as well * 6/4/12 * - fixed switch cases * - fixed int operands with <1 result */ /* Copyright (C) 1991-2005 The National Gallery This library 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 2.1 of the License, or (at your option) any later version. This library 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 library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /* These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk */ /* #define DEBUG */ #ifdef HAVE_CONFIG_H #include #endif /*HAVE_CONFIG_H*/ #include #include #include #include #include #include "binary.h" typedef VipsBinary VipsDivide; typedef VipsBinaryClass VipsDivideClass; G_DEFINE_TYPE( VipsDivide, vips_divide, VIPS_TYPE_BINARY ); /* Complex divide. */ #ifdef USE_MODARG_DIV /* This is going to be much slower */ #define CLOOP( TYPE ) { \ TYPE * restrict left = (TYPE *) in[0]; \ TYPE * restrict right = (TYPE *) in[1]; \ TYPE * restrict q = (TYPE *) out; \ int i; \ \ for( i = 0; i < sz; i++ ) { \ if( right[0] == 0.0 && \ right[1] == 0.0 ) { \ q[0] = 0.0; \ q[1] = 0.0; \ } \ else { \ double arg = atan2( left[1], left[0] ) - \ atan2( right[1], right[0] ); \ double mod = hypot( left[1], left[0] ) / \ hypot( right[1], right[0] ); \ \ q[0] = mod * cos( arg ); \ q[1] = mod * sin( arg ); \ } \ \ left += 2; \ right += 2; \ q += 2; \ } \ } #else /* USE_MODARG_DIV */ #define CLOOP( TYPE ) { \ TYPE * restrict left = (TYPE *) in[0]; \ TYPE * restrict right = (TYPE *) in[1]; \ TYPE * restrict q = (TYPE *) out; \ int i; \ \ for( i = 0; i < sz; i++ ) { \ if( right[0] == 0.0 && \ right[1] == 0.0 ) { \ q[0] = 0.0; \ q[1] = 0.0; \ } \ else if( VIPS_FABS( right[0] ) > VIPS_FABS( right[1] ) ) { \ double a = right[1] / right[0]; \ double b = right[0] + right[1] * a; \ \ q[0] = (left[0] + left[1] * a) / b; \ q[1] = (left[1] - left[0] * a) / b; \ } \ else { \ double a = right[0] / right[1]; \ double b = right[1] + right[0] * a; \ \ q[0] = (left[0] * a + left[1]) / b; \ q[1] = (left[1] * a - left[0]) / b; \ } \ \ left += 2; \ right += 2; \ q += 2; \ } \ } #endif /* USE_MODARG_DIV */ /* Real divide. Cast in to OUT before divide so we work for float output. */ #define RLOOP( IN, OUT ) { \ IN * restrict left = (IN *) in[0]; \ IN * restrict right = (IN *) in[1]; \ OUT * restrict q = (OUT *) out; \ \ for( x = 0; x < sz; x++ ) \ q[x] = right[x] == 0 ? 0 : (OUT) left[x] / (OUT) right[x]; \ } static void vips_divide_buffer( VipsArithmetic *arithmetic, VipsPel *out, VipsPel **in, int width ) { VipsImage *im = arithmetic->ready[0]; const int sz = width * vips_image_get_bands( im ); int x; /* Keep types here in sync with vips_divide_format_table[] * below. */ switch( vips_image_get_format( im ) ) { case VIPS_FORMAT_CHAR: RLOOP( signed char, float ); break; case VIPS_FORMAT_UCHAR: RLOOP( unsigned char, float ); break; case VIPS_FORMAT_SHORT: RLOOP( signed short, float ); break; case VIPS_FORMAT_USHORT: RLOOP( unsigned short, float ); break; case VIPS_FORMAT_INT: RLOOP( signed int, float ); break; case VIPS_FORMAT_UINT: RLOOP( unsigned int, float ); break; case VIPS_FORMAT_FLOAT: RLOOP( float, float ); break; case VIPS_FORMAT_DOUBLE: RLOOP( double, double ); break; case VIPS_FORMAT_COMPLEX: CLOOP( float ); break; case VIPS_FORMAT_DPCOMPLEX: CLOOP( double ); break; default: g_assert_not_reached(); } } /* Save a bit of typing. */ #define UC VIPS_FORMAT_UCHAR #define C VIPS_FORMAT_CHAR #define US VIPS_FORMAT_USHORT #define S VIPS_FORMAT_SHORT #define UI VIPS_FORMAT_UINT #define I VIPS_FORMAT_INT #define F VIPS_FORMAT_FLOAT #define X VIPS_FORMAT_COMPLEX #define D VIPS_FORMAT_DOUBLE #define DX VIPS_FORMAT_DPCOMPLEX /* Type promotion for division. Sign and value preserving. Make sure * these match the case statement in divide_buffer() above. */ static int vips_divide_format_table[10] = { /* UC C US S UI I F X D DX */ F, F, F, F, F, F, F, X, D, DX }; static void vips_divide_class_init( VipsDivideClass *class ) { VipsObjectClass *object_class = (VipsObjectClass *) class; VipsArithmeticClass *aclass = VIPS_ARITHMETIC_CLASS( class ); object_class->nickname = "divide"; object_class->description = _( "divide two images" ); aclass->process_line = vips_divide_buffer; vips_arithmetic_set_format_table( aclass, vips_divide_format_table ); } static void vips_divide_init( VipsDivide *divide ) { } /** * vips_divide: * @left: input image * @right: input image * @out: (out): output image * @...: %NULL-terminated list of optional named arguments * * This operation calculates @in1 / @in2 and writes the result to @out. If any * pixels in @in2 are zero, the corresponding pixel in @out is also zero. * * If the images differ in size, the smaller image is enlarged to match the * larger by adding zero pixels along the bottom and right. * * If the number of bands differs, one of the images * must have one band. In this case, an n-band image is formed from the * one-band image by joining n copies of the one-band image together, and then * the two n-band images are operated upon. * * The two input images are cast up to the smallest common format (see table * Smallest common format in * arithmetic), then the * following table is used to determine the output type: * * * vips_divide() type promotion * * * * input type * output type * * * * * uchar * float * * * char * float * * * ushort * float * * * short * float * * * uint * float * * * int * float * * * float * float * * * double * double * * * complex * complex * * * double complex * double complex * * * *
* * In other words, the output type is just large enough to hold the whole * range of possible values. * * See also: vips_multiply(), vips_linear(), vips_pow(). * * Returns: 0 on success, -1 on error */ int vips_divide( VipsImage *left, VipsImage *right, VipsImage **out, ... ) { va_list ap; int result; va_start( ap, out ); result = vips_call_split( "divide", ap, left, right, out ); va_end( ap ); return( result ); }