/*############################################################################# * 文件名：cmp_dct8x8.c * 功能：  比較8×8離散余弦變換后圖像質量 * 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 i, j;  int c;  int m = 16;  int print_psnr = 0;  int print_psnr_only = 0;  double error = 0.0;  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 ((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, "w")) == 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) {    fprintf(stderr, "%s: original image file not specified, use -i file option\n", progname);    exit(1);  }  pgm_readpgminit(in, &in_cols, &in_rows, &in_maxval, &in_format);  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);  }  if (cols % NJPEG) {    fprintf(stderr, "%s: image width %d not a multiple of %d\n", progname, cols, NJPEG);    exit(1);  }  if (rows % NJPEG) {    fprintf(stderr, "%s: image height %d not a multiple of %d\n", progname, rows, NJPEG);    exit(1);  }  cols = in_cols;  rows = in_rows;  format = in_format;  maxval = in_maxval;  input_image = pgm_allocarray(cols, NJPEG);  orig_image = pgm_allocarray(cols, NJPEG);  init_dct_8x8();  input_dcts = alloc_coeffs_8x8();  orig_dcts = alloc_coeffs_8x8();  output = alloc_grays(cols, NJPEG);  if (!print_psnr_only)    pgm_writepgminit(out, cols, rows, maxval, 0);  for (row = 0; row < rows; row += NJPEG) {    for (i = 0; i < NJPEG; i++) {      pgm_readpgmrow(in, input_image[row % NJPEG], cols, maxval, format);      pgm_readpgmrow(orig, orig_image[row % NJPEG], cols, maxval, format);    }    for (col = 0; col < cols; col += NJPEG) {      fdct_block_8x8(input_image, col, 0, input_dcts);      fdct_block_8x8(orig_image, col, 0, orig_dcts);      for (i = 0; i < NJPEG; i++)        for (j = 0; j < NJPEG; j++)          error += sqr(input_dcts[j][i + cols] - orig_dcts[j][i + cols]);          output[j][i + col] = PIXELRANGE(fabs(input_dcts[j][i + cols] - orig_dcts[j][i + cols]) * m);    }    if (!print_psnr_only) {      for (i = 0; i < NJPEG; i++)        pgm_writepgmrow(out, output[i], cols, maxval, 0);    }  }  fclose(in);  fclose(orig);  if (!print_psnr_only)    fclose(out);  pgm_freearray(input_image, NJPEG);  pgm_freearray(orig_image, NJPEG);  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);}