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/* ppmto3d.c - convert a portable pixmap to a portable graymap
**
** Copyright (C) 1989 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation. This software is provided "as is" without express or
** implied warranty.
*/
#include "ppm.h"
#include "lum.h"
static void
computeGrayscaleRow(const pixel * const inputRow,
gray * const outputRow,
pixval const maxval,
unsigned int const cols) {
if (maxval <= 255) {
unsigned int col;
/* Use fast approximation to 0.299 r + 0.587 g + 0.114 b. */
for (col = 0; col < cols; ++col)
outputRow[col] = ppm_fastlumin(inputRow[col]);
} else {
unsigned int col;
/* Can't use fast approximation, so fall back on floats. */
for (col = 0; col < cols; ++col)
outputRow[col] = PPM_LUMIN(inputRow[col]) + 0.5;
}
}
int
main (int argc, char *argv[]) {
int offset;
int cols, rows, row;
pixel* pixelrow;
pixval maxval;
FILE* Lifp;
pixel* Lpixelrow;
gray* Lgrayrow;
int Lrows, Lcols, Lformat;
pixval Lmaxval;
FILE* Rifp;
pixel* Rpixelrow;
gray* Rgrayrow;
int Rrows, Rcols, Rformat;
pixval Rmaxval;
ppm_init (&argc, argv);
if (argc-1 > 3 || argc-1 < 2)
pm_error("Wrong number of arguments (%d). Arguments are "
"leftppmfile rightppmfile [horizontal_offset]", argc-1);
Lifp = pm_openr (argv[1]);
Rifp = pm_openr (argv[2]);
if (argc-1 >= 3)
offset = atoi (argv[3]);
else
offset = 30;
ppm_readppminit (Lifp, &Lcols, &Lrows, &Lmaxval, &Lformat);
ppm_readppminit (Rifp, &Rcols, &Rrows, &Rmaxval, &Rformat);
if ((Lcols != Rcols) || (Lrows != Rrows) ||
(Lmaxval != Rmaxval) ||
(PPM_FORMAT_TYPE(Lformat) != PPM_FORMAT_TYPE(Rformat)))
pm_error ("Pictures are not of same size and format");
cols = Lcols;
rows = Lrows;
maxval = Lmaxval;
ppm_writeppminit (stdout, cols, rows, maxval, 0);
Lpixelrow = ppm_allocrow (cols);
Lgrayrow = pgm_allocrow (cols);
Rpixelrow = ppm_allocrow (cols);
Rgrayrow = pgm_allocrow (cols);
pixelrow = ppm_allocrow (cols);
for (row = 0; row < rows; ++row) {
ppm_readppmrow(Lifp, Lpixelrow, cols, maxval, Lformat);
ppm_readppmrow(Rifp, Rpixelrow, cols, maxval, Rformat);
computeGrayscaleRow(Lpixelrow, Lgrayrow, maxval, cols);
computeGrayscaleRow(Rpixelrow, Rgrayrow, maxval, cols);
{
int col;
gray* LgP;
gray* RgP;
pixel* pP;
for (col = 0, pP = pixelrow, LgP = Lgrayrow, RgP = Rgrayrow;
col < cols + offset;
++col) {
if (col < offset/2)
++LgP;
else if (col >= offset/2 && col < offset) {
const pixval Blue = (pixval) (float) *LgP;
const pixval Red = (pixval) 0;
PPM_ASSIGN (*pP, Red, Blue, Blue);
++LgP;
++pP;
} else if (col >= offset && col < cols) {
const pixval Red = (pixval) (float) *RgP;
const pixval Blue = (pixval) (float) *LgP;
PPM_ASSIGN (*pP, Red, Blue, Blue);
++LgP;
++RgP;
++pP;
} else if (col >= cols && col < cols + offset/2) {
const pixval Blue = (pixval) 0;
const pixval Red = (pixval) (float) *RgP;
PPM_ASSIGN (*pP, Red, Blue, Blue);
++RgP;
++pP;
} else
++RgP;
}
}
ppm_writeppmrow(stdout, pixelrow, cols, maxval, 0);
}
pm_close(Lifp);
pm_close(Rifp);
pm_close(stdout);
return 0;
}
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