sane-project-backends/backend/u12-map.c

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5.6 KiB
C

/* @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 ............................................................*/