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/* mrftopbm - convert mrf to pbm
* public domain by RJM
*
* Adapted to Netpbm by Bryan Henderson 2003.08.09. Bryan got his copy from
* ftp://ibiblio.org/pub/linux/apps/convert, dated 1997.08.19.
*
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <limits.h>
#include "pm_c_util.h"
#include "nstring.h"
#include "pbm.h"
static int bitbox;
static int bitsleft;
static void
bit_init(void) {
bitbox=0;
bitsleft=0;
}
static int
bit_input(FILE * const in) {
if (bitsleft == 0) {
int rc;
rc = fgetc(in);
if (rc == EOF)
pm_error("Unexpected EOF reading image data.");
bitbox = rc;
bitsleft = 8;
}
--bitsleft;
return((bitbox&(1<<bitsleft))?1:0);
}
static void
doSquare(FILE * const ifP,
unsigned char * const image,
unsigned int const ulCol,
unsigned int const ulRow,
unsigned int const imageWidth,
unsigned int const size) {
/*----------------------------------------------------------------------------
Do a square of side 'size', whose upper left corner is at (ulCol, ulRow).
The contents of that square are next in file *ifP, in MRF format.
Return the pixel values of the square in the corresponding position of
image[], which is a concatenation of rows 'imageWidth' pixels wide, one
byte per pixel.
-----------------------------------------------------------------------------*/
if (size == 1 || bit_input(ifP)) {
/* It's all black or all white. Next bit says which. */
unsigned int const c = bit_input(ifP);
unsigned int rowOfSquare;
for (rowOfSquare = 0; rowOfSquare < size; ++rowOfSquare) {
unsigned int colOfSquare;
for (colOfSquare = 0; colOfSquare < size; ++colOfSquare) {
unsigned int rowOfImage = ulRow + rowOfSquare;
unsigned int colOfImage = ulCol + colOfSquare;
image[rowOfImage * imageWidth + colOfImage] = c;
}
}
} else {
/* Square is not all one color, so recurse. Do each of the four
quadrants of this square individually.
*/
unsigned int const quadSize = size/2;
doSquare(ifP, image, ulCol, ulRow,
imageWidth, quadSize);
doSquare(ifP, image, ulCol + quadSize, ulRow,
imageWidth, quadSize);
doSquare(ifP, image, ulCol, ulRow + quadSize,
imageWidth, quadSize);
doSquare(ifP, image, ulCol + quadSize, ulRow + quadSize,
imageWidth, quadSize);
}
}
static void
writeOutput(FILE * const ofP,
int const cols,
int const rows,
const unsigned char * const image) {
/* w64 is units-of-64-bits width */
unsigned int const w64 = (cols+63)/64;
bit * bitrow;
unsigned int row;
pbm_writepbminit(ofP, cols, rows, FALSE);
bitrow = pbm_allocrow(cols);
for (row = 0; row < rows; ++row) {
unsigned int col;
for (col = 0; col < cols; ++col)
bitrow[col] =
(image[row * (w64*64) + col] == 1) ? PBM_WHITE : PBM_BLACK;
pbm_writepbmrow(ofP, bitrow, cols, FALSE);
}
pbm_freerow(bitrow);
}
static void
readMrfImage(FILE * const ifP,
bool const expandAll,
unsigned char ** const imageP,
unsigned int * const colsP,
unsigned int * const rowsP) {
static unsigned char buf[128];
unsigned int rows;
unsigned int cols;
unsigned int w64, h64;
unsigned char * image;
unsigned int bytesRead;
bytesRead = fread(buf, 1, 13, ifP);
if (bytesRead != 13)
pm_error("Input in not an MRF image. We know this because it is less "
"than 13 bytes, the size of an MRF header");
if (memcmp(buf, "MRF1", 4) != 0)
pm_error("Input is not an MRF image. "
"We know this because it does not start with 'MRF1'.");
if (buf[12] != 0)
pm_error("can't handle file subtype %u", buf[12]);
cols = (buf[4] << 24) | (buf[5] << 16) | (buf[06] << 8) | buf[07] << 0;
rows = (buf[8] << 24) | (buf[9] << 16) | (buf[10] << 8) | buf[11] << 0;
/* w64 is units-of-64-bits width, h64 same for height */
w64 = (cols+63)/64;
h64 = (rows+63)/64;
if (expandAll) {
*colsP = w64*64;
*rowsP = h64*64;
} else {
*colsP = cols;
*rowsP = rows;
}
if (UINT_MAX/w64/64/h64/64 == 0)
pm_error("Ridiculously large, unprocessable image: %u cols x %u rows",
cols, rows);
image = calloc(w64*h64*64*64, 1);
if (image == NULL)
pm_error("Unable to get memory for raster");
/* now recursively input squares. */
bit_init();
{
unsigned int row;
for (row = 0; row < h64; ++row) {
unsigned int col;
for (col = 0; col < w64; ++col)
doSquare(ifP, image, col*64, row*64, w64*64, 64);
}
}
*imageP = image;
}
int
main(int argc, char *argv[]) {
FILE *ifP;
FILE *ofP;
unsigned char *image;
bool expandAll;
unsigned int cols, rows;
pbm_init(&argc, argv);
expandAll = FALSE; /* initial assumption */
if (argc-1 >= 1 && streq(argv[1], "-a")) {
expandAll = TRUE;
argc--,argv++;
}
if (argc-1 > 1)
pm_error("Too many arguments: %d. Only argument is input file",
argc-1);
if (argc-1 == 1)
ifP = pm_openr(argv[1]);
else
ifP = stdin;
ofP = stdout;
readMrfImage(ifP, expandAll, &image, &cols, &rows);
pm_close(ifP);
writeOutput(ofP, cols, rows, image);
free(image);
return 0;
}
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