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  1. #include <pgm.h>
  2. #include <math.h>
  3.  
  4. enum { N = 4, M = 4 };
  5.  
  6. typedef struct pgm_t {
  7.   int cols, rows;
  8.   gray maxval;
  9.   gray **pgm;
  10. } pgm;
  11.  
  12. struct pgm_t load_pgm( const char *filename ) {
  13.   FILE *fp = fopen( filename, "w" );
  14.   struct pgm_t pgm;
  15.   pgm.pgm = pgm_readpgm( fp, &pgm.cols, &pgm.rows, &pgm.maxval );
  16.   fclose( fp );
  17.   return pgm;
  18. }
  19.  
  20. void store_pgm( const char *filename, const struct pgm_t *pgm ) {
  21.   FILE *fp = fopen( filename, "w" );
  22.   pgm_writepgm( fp, pgm->pgm, pgm->cols, pgm->rows, pgm->maxval, 0 );
  23.   fclose( fp );
  24. }
  25.  
  26. struct pgm_t mesh( const struct pgm_t *src, int w, int h ) {
  27.   struct pgm_t result;
  28.   int x, y;
  29.   double d = (double)(src->cols * src->rows)/w/h;
  30.  
  31.   result.maxval = src->maxval;
  32.   result.cols = w;
  33.   result.rows = h;
  34.   result.pgm = pgm_allocarray( w, h );
  35.   for( x = 0; x < src->cols; ++x ) {
  36.     for( y = 0; y < src->rows; ++y ) {
  37.       result.pgm[x/w][y/h] += src->pgm[x][y];
  38.     }
  39.   }
  40.  
  41.   for( x = 0; x < w; ++x ) {
  42.     for( y = 0; y < h; ++y ) {
  43.       result.pgm[x][y] /= d;
  44.     }
  45.   }
  46.  
  47.   return result;
  48. }
  49. double calc_similarness( const struct pgm_t *a, const struct pgm_t *b ) {
  50.   double result = 0;
  51.   int x, y;
  52. #if 0
  53.   assert( a->cols == b->cols );
  54.   assert( a->rows == b->rows );
  55.   assert( a->maxval == b->maxval );
  56. #endif
  57.   for( x = 0; x < a->cols; ++x ) {
  58.     for( y = 0; y < a->rows; ++y ) {
  59.       result += fabs( a->pgm[x][y] - b->pgm[x][y] );
  60.     }
  61.   }
  62.   return result / a->cols / a->rows;
  63. }
  64.  
  65. int main( int argc, const char *argv[]) {
  66.   if( strcmp( argv[0], "(1)" ) == 0 ) {
  67.     struct pgm_t g = load_pgm( argv[1] );
  68.     struct pgm_t g2 = mesh( &g, N, M );
  69.     store_pgm( "result-1.pgm", &g2 );
  70.   }
  71.   else if( strcmp( argv[0], "(2)" ) == 0 ) {
  72.     struct pgm_t in = load_pgm( argv[1] );
  73.     struct pgm_t meshed = mesh( &in, N, M );
  74.     double max_similarness = 0.0;
  75.     int most_similar_number = -1;
  76.     int i;
  77.     for( i = 0; i < 10; ++i ) {
  78.       char buf[32];
  79.       sprintf( buf, "std%i.pgm", i );
  80.       struct pgm_t std_N = load_pgm( buf );
  81.       struct pgm_t meshed_N = mesh( &std_N, N, M );
  82.       double similarness = calc_similarness( &in, &std_N );
  83.       if( similarness > max_similarness ) {
  84.         max_similarness = similarness;
  85.         most_similar_number = i;
  86.       }
  87.       printf( "SIMILARITY TO #%i IS %f\n", i, similarness );
  88.     }
  89.     printf( "MOST SIMILAR NUMBER IS: %d", most_similar_number );
  90.   }
  91.   else if( strcmp( argv[0], "(3)" ) == 0 ) {
  92.   }
  93. }
  94.  
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https://ideone.com/nONFC
language:
C (gcc 8.3)
created:
12 years ago
visibility:
public

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