// Helper function to divide the input blobs over noise, small, medium
// and large lists. Blobs small in height and (small in width or large in width)
// go in the noise list. Dash (-) candidates go in the small list, and
// medium and large are by height.
// SIDE-EFFECT: reset all blobs to initial state by calling Init().
static void SizeFilterBlobs(int min_height, int max_height,
BLOBNBOX_LIST* src_list,
BLOBNBOX_LIST* noise_list,
BLOBNBOX_LIST* small_list,
BLOBNBOX_LIST* medium_list,
BLOBNBOX_LIST* large_list) {
BLOBNBOX_IT noise_it(noise_list);
BLOBNBOX_IT small_it(small_list);
BLOBNBOX_IT medium_it(medium_list);
BLOBNBOX_IT large_it(large_list);
for (BLOBNBOX_IT src_it(src_list); !src_it.empty(); src_it.forward()) {
BLOBNBOX* blob = src_it.extract();
blob->ReInit();
int width = blob->bounding_box().width();
int height = blob->bounding_box().height();
if (height < min_height &&
(width < min_height || width > max_height))
noise_it.add_after_then_move(blob);
else if (height > max_height)
large_it.add_after_then_move(blob);
else if (height < min_height)
small_it.add_after_then_move(blob);
else
medium_it.add_after_then_move(blob);
}
}
// Moves blobs that look like they don't sit well on a textline from the
// input blobs list to the output small_blobs list.
// This gets them away from initial textline finding to stop diacritics
// from forming incorrect textlines. (Introduced mainly to fix Thai.)
void TextlineProjection::MoveNonTextlineBlobs(
BLOBNBOX_LIST* blobs, BLOBNBOX_LIST* small_blobs) const {
BLOBNBOX_IT it(blobs);
BLOBNBOX_IT small_it(small_blobs);
for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
BLOBNBOX* blob = it.data();
const TBOX& box = blob->bounding_box();
bool debug = AlignedBlob::WithinTestRegion(2, box.left(),
box.bottom());
if (BoxOutOfHTextline(box, NULL, debug) && !blob->UniquelyVertical()) {
blob->ClearNeighbours();
small_it.add_to_end(it.extract());
}
}
}
