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Diffstat (limited to 'backend/u12-map.c')
| -rw-r--r-- | backend/u12-map.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/backend/u12-map.c b/backend/u12-map.c new file mode 100644 index 0000000..7d2f84a --- /dev/null +++ b/backend/u12-map.c @@ -0,0 +1,192 @@ +/* @file u12_map.c + * @brief functions to create and manipulate gamma lookup tables. + * + * Copyright (C) 2003-2004 Gerhard Jaeger <gerhard@gjaeger.de> + * + * History: + * - 0.01 - initial version + * - 0.02 - inverting map when scanning binary images + * - changed u12map_Adjust() + * . + * <hr> + * This file is part of the SANE package. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU 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 + * General Public License for more details. + * + * You should have received a copy of the GNU 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. + * + * As a special exception, the authors of SANE give permission for + * additional uses of the libraries contained in this release of SANE. + * + * The exception is that, if you link a SANE library with other files + * to produce an executable, this does not by itself cause the + * resulting executable to be covered by the GNU General Public + * License. Your use of that executable is in no way restricted on + * account of linking the SANE library code into it. + * + * This exception does not, however, invalidate any other reasons why + * the executable file might be covered by the GNU General Public + * License. + * + * If you submit changes to SANE to the maintainers to be included in + * a subsequent release, you agree by submitting the changes that + * those changes may be distributed with this exception intact. + * + * If you write modifications of your own for SANE, it is your choice + * whether to permit this exception to apply to your modifications. + * If you do not wish that, delete this exception notice. + * <hr> + */ + +/** + * @param s - pointer to the scanner specific structure + * @return The function always returns SANE_STATUS_GOOD + */ +static SANE_Status u12map_InitGammaSettings( U12_Device *dev ) +{ + int i, j, val; + double gamma; + + dev->gamma_length = 4096; + dev->gamma_range.min = 0; + dev->gamma_range.max = 255; + dev->gamma_range.quant = 0; + + DBG( _DBG_INFO, "Presetting Gamma tables (len=%u)\n", dev->gamma_length ); + DBG( _DBG_INFO, "----------------------------------\n" ); + + /* preset the gamma maps */ + for( i = 0; i < 4; i++ ) { + + switch( i ) { + case 1: gamma = dev->adj.rgamma; break; + case 2: gamma = dev->adj.ggamma; break; + case 3: gamma = dev->adj.bgamma; break; + default: gamma = dev->adj.graygamma; break; + } + + for( j = 0; j < dev->gamma_length; j++ ) { + + val = (dev->gamma_range.max * + pow((double) j / ((double)dev->gamma_length - 1.0), + 1.0 / gamma )); + + if( val > dev->gamma_range.max ) + val = dev->gamma_range.max; + + dev->gamma_table[i][j] = val; + } + } + return SANE_STATUS_GOOD; +} + +/** Check the gamma vectors we got back and limit if necessary + * @param s - pointer to the scanner specific structure + * @return nothing + */ +static void u12map_CheckGammaSettings( U12_Device *dev ) +{ + int i, j; + + for( i = 0; i < 4 ; i++ ) { + for( j = 0; j < dev->gamma_length; j++ ) { + if( dev->gamma_table[i][j] > dev->gamma_range.max ) { + dev->gamma_table[i][j] = dev->gamma_range.max; + } + } + } +} + +/** adjust acording to brightness and contrast + */ +static void u12map_Adjust( U12_Device *dev, int which, SANE_Byte *buf ) +{ + int i; + u_long *pdw; + double b, c, tmp; + + DBG( _DBG_INFO, "u12map_Adjust(%u)\n", which ); + + /* adjust brightness (b) and contrast (c) using the function: + * + * s'(x,y) = (s(x,y) + b) * c + * b = [-127, 127] + * c = [0,2] + */ + + /* scale brightness and contrast... + */ + b = ((double)dev->DataInf.siBrightness * 192.0)/100.0; + c = ((double)dev->DataInf.siContrast + 100.0)/100.0; + + DBG( _DBG_INFO, "* brightness = %i -> %i\n", + dev->DataInf.siBrightness, (SANE_Byte)b); + DBG( _DBG_INFO, "* contrast*100 = %i -> %i\n", + dev->DataInf.siContrast, (int)(c*100)); + + for( i = 0; i < dev->gamma_length; i++ ) { + + if((_MAP_MASTER == which) || (_MAP_RED == which)) { + tmp = ((double)(dev->gamma_table[0][i] + b)) * c; + if( tmp < 0 ) tmp = 0; + if( tmp > 255 ) tmp = 255; + buf[i] = (SANE_Byte)tmp; + } + + if((_MAP_MASTER == which) || (_MAP_GREEN == which)) { + tmp = ((double)(dev->gamma_table[1][i] + b)) * c; + if( tmp < 0 ) tmp = 0; + if( tmp > 255 ) tmp = 255; + buf[4096+i] = (SANE_Byte)tmp; + } + + if((_MAP_MASTER == which) || (_MAP_BLUE == which)) { + tmp = ((double)(dev->gamma_table[2][i] + b)) * c; + if( tmp < 0 ) tmp = 0; + if( tmp > 255 ) tmp = 255; + buf[8192+i] = (SANE_Byte)tmp; + } + } + + if((dev->DataInf.dwScanFlag & _SCANDEF_Negative) || + (dev->DataInf.wPhyDataType == COLOR_BW)) { + DBG( _DBG_INFO, "inverting...\n" ); + + if((_MAP_MASTER == which) || (_MAP_RED == which)) { + + DBG( _DBG_INFO, "inverting RED map\n" ); + pdw = (u_long*)&buf[0]; + for( i = dev->gamma_length / 4; i; i--, pdw++ ) + *pdw = ~(*pdw); + } + + if((_MAP_MASTER == which) || (_MAP_GREEN == which)) { + + DBG( _DBG_INFO, "inverting GREEN map\n" ); + pdw = (u_long*)&buf[4096]; + for( i = dev->gamma_length / 4; i; i--, pdw++ ) + *pdw = ~(*pdw); + } + + if((_MAP_MASTER == which) || (_MAP_BLUE == which)) { + + DBG( _DBG_INFO, "inverting BLUE map\n" ); + pdw = (u_long*)&buf[8192]; + for( i = dev->gamma_length / 4; i; i--, pdw++ ) + *pdw = ~(*pdw); + } + } +} + +/* END U12-MAP.C ............................................................*/ |