📄 cmp_dct.c
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/*#############################################################################
* 文件名:com_dct.c
* 功能: 比较DCT变换后图像质量
* modified by PRTsinghua@hotmail.com
#############################################################################*/
#include "wm.h"
#include "dct.h"
#include "gray.h"
#include "pgm.h"
char *progname;
void usage(void) {
fprintf(stderr, "usage: %s [-h] [-m n] [-o file] [-pP] -i file file\n\n", progname);
fprintf(stderr, "\t-h\t\tprint usage\n");
fprintf(stderr, "\t-i file\t\toriginal image file\n");
fprintf(stderr, "\t-m n\t\tmultiplication factor (default 16)\n");
fprintf(stderr, "\t-o file\t\toutput file\n");
fprintf(stderr, "\t-p\t\tprint PSNR, RMS and MSE\n");
fprintf(stderr, "\t-P\t\tonly print PSNR, RMS and MSE, no difference image\n");
exit(0);
}
int main(int argc, char *argv[])
{
FILE *in = stdin;
FILE *out = stdout;
FILE *orig = NULL;
gray **input_image;
gray **orig_image;
double **input_dcts;
double **orig_dcts;
gray **output;
char output_name[MAXPATHLEN] = "(stdout)";
char input_name[MAXPATHLEN] = "(stdin)";
char orig_name[MAXPATHLEN];
int in_cols, in_rows, in_format;
gray in_maxval;
int orig_cols, orig_rows, orig_format;
gray orig_maxval;
int cols, rows, format;
gray maxval;
int col, row;
int no_orig = 0;
int c;
double error = 0.0;
int print_psnr = 0;
int print_psnr_only = 0;
int m = 16;
progname = argv[0];
pgm_init(&argc, argv); wm_init();
while ((c = getopt(argc, argv, "h?i:m:o:pP")) != EOF) {
switch (c) {
case 'h':
case '?':
usage();
break;
case 'i':
if (!strcmp(optarg, "-")) {
no_orig = 1;
strcpy(orig_name, "(zero)");
}
else {
if ((orig = fopen(optarg, "rb")) == NULL) {
fprintf(stderr, "%s: unable to open original image file %s\n", progname, optarg);
exit(1);
}
strcpy(orig_name, optarg);
}
break;
case 'm':
m = atoi(optarg);
if (m <= 0) {
fprintf(stderr, "%s: multiplication factor %d out of range\n", progname, m);
exit(1);
}
break;
case 'o':
if ((out = fopen(optarg, "wb")) == NULL) {
fprintf(stderr, "%s: unable to open output file %s\n", progname, optarg);
exit(1);
}
strcpy(output_name, optarg);
break;
case 'p':
print_psnr = 1;
break;
case 'P':
print_psnr_only = 1;
break;
}
}
argc -= optind;
argv += optind;
if (argc > 1) {
usage();
exit(1);
}
if (argc == 1 && *argv[0] != '-')
if ((in = fopen(argv[0], "rb")) == NULL) {
fprintf(stderr, "%s: unable to open input file %s\n", progname, argv[0]);
exit(1);
}
else
strcpy(input_name, argv[0]);
if (!orig && !no_orig) {
fprintf(stderr, "%s: original image file not specified, using zero image\n", progname);
strcpy(orig_name, "(zero)");
no_orig = 1;
}
pgm_readpgminit(in, &in_cols, &in_rows, &in_maxval, &in_format);
if (!no_orig) {
pgm_readpgminit(orig, &orig_cols, &orig_rows, &orig_maxval, &orig_format);
if (in_cols != orig_cols || in_rows != orig_rows) {
fprintf(stderr, "%s: input image %s does not match dimensions of original image %s\n", progname, input_name, orig_name);
exit(1);
}
}
cols = in_cols;
rows = in_rows;
format = in_format;
maxval = in_maxval;
input_image = pgm_allocarray(cols, rows);
orig_image = pgm_allocarray(cols, rows);
init_dct_NxN(cols, rows);
input_dcts = alloc_coeffs(cols, rows);
orig_dcts = alloc_coeffs(cols, rows);
output = alloc_grays(cols, rows);
if (no_orig) {
for (row = 0; row < rows; row++) {
pgm_readpgmrow(in, input_image[row], cols, maxval, format);
bzero(orig_image[row], sizeof(gray) * cols);
}
}
else {
for (row = 0; row < rows; row++) {
pgm_readpgmrow(in, input_image[row], cols, maxval, format);
pgm_readpgmrow(orig, orig_image[row], cols, maxval, format);
}
}
fclose(in);
if (!no_orig)
fclose(orig);
fdct_NxN(input_image, input_dcts);
fdct_NxN(orig_image, orig_dcts);
for (row = 0; row < rows; row++)
for (col = 0; col < cols; col++) {
error += sqr(input_dcts[row][col] - orig_dcts[row][col]);
output[row][col] = PIXELRANGE(fabs(input_dcts[row][col] - orig_dcts[row][col]) * m);
}
if (!print_psnr_only) {
pgm_writepgminit(out, cols, rows, maxval, 0);
for (row = 0; row < rows; row++)
pgm_writepgmrow(out, output[row], cols, maxval, 0);
fclose(out);
}
pgm_freearray(input_image, rows);
pgm_freearray(orig_image, rows);
free_coeffs(input_dcts);
free_coeffs(orig_dcts);
free_grays(output);
if (print_psnr || print_psnr_only) {
double mse = error / (double) (cols * rows);
double rmse = sqrt(mse);
double psnr = 20.0 * log(255.0 / rmse) / log(10.0);
FILE *print = print_psnr_only ? out : stderr;
if (mse > 0.0)
fprintf(print, "PSNR: %lf dB\n", psnr);
else
fprintf(print, "PSNR: inf\n");
fprintf(print, "RMS: %lf\n", rmse);
fprintf(print, "MSE: %lf\n", mse);
}
exit(0);
}
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