BOOL8 PIXROW::extend( //image array
IMAGELINE *imlines,
BOX &imbox,
PIXROW *prev, //for prev blob
PIXROW *next, //for next blob
INT16 foreground_colour) {
INT16 i;
INT16 x_offset = imbox.left ();
INT16 limit;
INT16 left_limit;
INT16 right_limit;
UINT8 *pixels = NULL;
UINT8 *pixels_below = NULL; //row below current
UINT8 *pixels_above = NULL; //row above current
BOOL8 changed = FALSE;
pixels_above = imlines[0].pixels;
for (i = 0; i < row_count; i++) {
pixels_below = pixels;
pixels = pixels_above;
if (i < (row_count - 1))
pixels_above = imlines[i + 1].pixels;
else
pixels_above = NULL;
/* Extend Left by one pixel*/
if (prev == NULL || prev->max[i] < prev->min[i])
limit = imbox.left ();
else
limit = prev->max[i] + 1;
if ((min[i] <= max[i]) &&
(min[i] > limit) &&
(pixels[min[i] - 1 - x_offset] == foreground_colour)) {
min[i]--;
changed = TRUE;
}
/* Extend Right by one pixel*/
if (next == NULL || next->min[i] > next->max[i])
limit = imbox.right () - 1;//-1 to index inside pix
else
limit = next->min[i] - 1;
if ((min[i] <= max[i]) &&
(max[i] < limit) &&
(pixels[max[i] + 1 - x_offset] == foreground_colour)) {
max[i]++;
changed = TRUE;
}
/* Extend down by one row */
if (pixels_below != NULL) {
if (min[i] < min[i - 1]) { //row goes left of row below
if (prev == NULL || prev->max[i - 1] < prev->min[i - 1])
left_limit = min[i];
else
left_limit = LARGEST (min[i], prev->max[i - 1] + 1);
}
else
left_limit = min[i - 1];
if (max[i] > max[i - 1]) { //row goes right of row below
if (next == NULL || next->min[i - 1] > next->max[i - 1])
right_limit = max[i];
else
right_limit = SMALLEST (max[i], next->min[i - 1] - 1);
}
else
right_limit = max[i - 1];
while ((left_limit <= right_limit) &&
(pixels_below[left_limit - x_offset] != foreground_colour))
left_limit++; //find black extremity
if ((left_limit <= right_limit) && (left_limit < min[i - 1])) {
min[i - 1] = left_limit; //widen left if poss
changed = TRUE;
}
while ((left_limit <= right_limit) &&
(pixels_below[right_limit - x_offset] != foreground_colour))
right_limit--; //find black extremity
if ((left_limit <= right_limit) && (right_limit > max[i - 1])) {
max[i - 1] = right_limit;//widen right if poss
changed = TRUE;
}
}
/* Extend up by one row */
if (pixels_above != NULL) {
if (min[i] < min[i + 1]) { //row goes left of row above
if (prev == NULL || prev->min[i + 1] > prev->max[i + 1])
left_limit = min[i];
else
left_limit = LARGEST (min[i], prev->max[i + 1] + 1);
}
else
left_limit = min[i + 1];
if (max[i] > max[i + 1]) { //row goes right of row above
if (next == NULL || next->min[i + 1] > next->max[i + 1])
right_limit = max[i];
else
right_limit = SMALLEST (max[i], next->min[i + 1] - 1);
}
else
right_limit = max[i + 1];
while ((left_limit <= right_limit) &&
(pixels_above[left_limit - x_offset] != foreground_colour))
left_limit++; //find black extremity
if ((left_limit <= right_limit) && (left_limit < min[i + 1])) {
min[i + 1] = left_limit; //widen left if poss
changed = TRUE;
}
while ((left_limit <= right_limit) &&
(pixels_above[right_limit - x_offset] != foreground_colour))
right_limit--; //find black extremity
if ((left_limit <= right_limit) && (right_limit > max[i + 1])) {
max[i + 1] = right_limit;//widen right if poss
changed = TRUE;
}
}
}
return changed;
}
int main()
{
printf("Largest 4,10,17,29 is %d",LARGEST(4,10,17,29));
return 0;
}
