sane-project-backends/backend/plustek-pp_scale.c

150 wiersze
4.0 KiB
C

/* @file plustek-pp_scale.c
* @brief Scaling functionality
*
* Copyright (C) 2000-2004 Gerhard Jaeger <gerhard@gjaeger.de>
*
* History:
* - 0.32 - initial version
* - 0.33 - no changes
* - 0.34 - no changes
* - 0.35 - no changes
* - 0.36 - no changes
* - 0.37 - no changes
* - 0.38 - no changes
* - 0.39 - no changes
* - 0.40 - no changes
* - 0.41 - no changes
* - 0.42 - changed include names
* - 0.43 - cleanup, removed floating point stuff
* .
* <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>
*/
#include "plustek-pp_scan.h"
/************************ exported functions *********************************/
/** scaling picture data in x-direction, using a DDA algo
* (digital differential analyzer).
*/
_LOC void ScaleX( pScanData ps, pUChar inBuf, pUChar outBuf )
{
UChar tmp;
int step;
int izoom;
int ddax;
register ULong i, j, x;
#ifdef DEBUG
_VAR_NOT_USED( dbg_level );
#endif
/* scale... */
izoom = (int)(1000000/ps->DataInf.XYRatio);
switch( ps->DataInf.wAppDataType ) {
case COLOR_BW : step = 0; break;
case COLOR_HALFTONE: step = 0; break;
case COLOR_256GRAY : step = 1; break;
case COLOR_TRUE24 : step = 3; break; /*NOTE: COLOR_TRUE32 is the same !*/
case COLOR_TRUE48 : step = 6; break;
default : step = 99; break;
}
/* when not supported, only copy the data
*/
if( 99 == step ) {
memcpy( outBuf, inBuf, ps->DataInf.dwAppBytesPerLine );
return;
}
/* now scale...
*/
ddax = 0;
x = 0;
if( 0 == step ) {
/* binary scaling
*/
memset( outBuf, 0, ps->DataInf.dwAppBytesPerLine );
for( i = 0; i < ps->DataInf.dwPhysBytesPerLine*8; i++ ) {
ddax -= 1000;
while( ddax < 0 ) {
tmp = inBuf[(i>>3)];
if((x>>3) < ps->DataInf.dwAppBytesPerLine ) {
if( 0 != (tmp &= (1 << ((~(i & 0x7))&0x7))))
outBuf[x>>3] |= (1 << ((~(x & 0x7))&0x7));
}
x++;
ddax += izoom;
}
}
} else {
/* color and gray scaling
*/
for( i = 0; i < ps->DataInf.dwPhysBytesPerLine*step; i+=step ) {
ddax -= 1000;
while( ddax < 0 ) {
for( j = 0; j < (ULong)step; j++ ) {
if((x+j) < ps->DataInf.dwAppBytesPerLine ) {
outBuf[x+j] = inBuf[i+j];
}
}
x += step;
ddax += izoom;
}
}
}
}
/* END PLUSTEK-PP_SCALE.C ...................................................*/