void Bitmap::equals_naive_blur(Bitmap &original)
{
allocate_bitmap(original.height, original.width);
// get the body:
for(int r = 1; r < height-1; r++)
{
for(int c = 1; c < width-1; c++)
{
bitmap[r][c].set(0);
for(int y = -1; y <= 1; y++)
{
for(int x = -1; x <= 1; x++)
{
bitmap[r][c] += original[r+y][c+x];
}
}
bitmap[r][c] /= 9;
}
}
// get the edges and corners:
for(int r = 0; r < height; r++)
{
int c_skip = (r==0 || r==height-1) ? 1 : width-1;
for(int c = 0; c < width; c += c_skip)
{
bitmap[r][c].set(0);
int count = 0;
for(int y = -1; y <= 1; y++)
{
for(int x = -1; x <= 1; x++)
{
int new_r = r+y, new_c = c+x;
if( 0 <= new_r && new_r < height && // the conditions since we know we're on some edge
0 <= new_c && new_c < width)
{
bitmap[r][c] += original[r+y][c+x];
count += 1;
}
}
}
bitmap[r][c] /= count;
}
}
}
int load_pnm_from_FILE(FILE *f, unsigned char ***pixels, int *width, int *height)
{
int maxval;
char type;
if (getc(f) != 'P')
{
fprintf(stderr, "PNM file not starts with 'P'\n");
exit(1);
}
type = getc(f);
skip_whitespace_and_comments(f);
switch(type)
{
case '4':
fscanf(f, "%d %d", width, height);
maxval = 255;
break;
case '5': case '6':
fscanf(f, "%d %d %d", width, height, &maxval);
break;
default:
fprintf(stderr, "only raw PNM files supported\n");
exit(1);
}
if (maxval != 255)
{
fprintf(stderr, "only 256-levels PNM supported\n");
exit(1);
}
switch(fgetc(f))
{
case ' ': case '\t': case '\r': case '\n':
break;
default:
fprintf(stderr, "corrupted PNM, current offset is %ld\n", ftell(f));
exit(1);
}
switch(type)
{
case '4':
*pixels = allocate_bitmap(*width, *height);
load_pbm_raster(f, *pixels, *width, *height);
return PBM;
case '5':
*pixels = allocate_bitmap(*width, *height);
fread(**pixels, *width, *height, f);
return PGM;
case '6':
*pixels = allocate_bitmap(*width * 3, *height);
fread(**pixels, *width * 3, *height, f);
return PPM;
default:
assert(0);
return 0;
}
}
