// Finds horizontal line objects in the given pix.
// Uses the given resolution to determine size thresholds instead of any
// that may be present in the pix.
// The output vectors are owned by the list and Frozen (cannot refit) by
// having no boxes, as there is no need to refit or merge separator lines.
void LineFinder::FindHorizontalLines(int resolution, Pix* pix,
TabVector_LIST* vectors) {
#ifdef HAVE_LIBLEPT
Pix* line_pix;
Boxa* boxes = GetHLineBoxes(resolution, pix, &line_pix);
C_BLOB_LIST line_cblobs;
int width = pixGetWidth(pix);
int height = pixGetHeight(pix);
ConvertBoxaToBlobs(height, width, &boxes, &line_cblobs);
// Make the BLOBNBOXes from the C_BLOBs.
BLOBNBOX_LIST line_bblobs;
C_BLOB_IT blob_it(&line_cblobs);
BLOBNBOX_IT bbox_it(&line_bblobs);
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
C_BLOB* cblob = blob_it.data();
BLOBNBOX* bblob = new BLOBNBOX(cblob);
bbox_it.add_to_end(bblob);
}
ICOORD bleft(0, 0);
ICOORD tright(height, width);
int vertical_x, vertical_y;
FindLineVectors(bleft, tright, &line_bblobs, &vertical_x, &vertical_y,
vectors);
if (!vectors->empty()) {
// Some lines were found, so erase the unused blobs from the line image
// and then subtract the line image from the source.
bbox_it.move_to_first();
for (bbox_it.mark_cycle_pt(); !bbox_it.cycled_list(); bbox_it.forward()) {
BLOBNBOX* blob = bbox_it.data();
if (blob->left_tab_type() == TT_UNCONFIRMED) {
const TBOX& box = blob->bounding_box();
// Coords are in tess format so filp x and y and then covert
// to leptonica by height -y.
Box* pixbox = boxCreate(box.bottom(), height - box.right(),
box.height(), box.width());
pixClearInRect(line_pix, pixbox);
boxDestroy(&pixbox);
}
}
pixDilateBrick(line_pix, line_pix, 3, 1);
pixSubtract(pix, pix, line_pix);
if (textord_tabfind_show_vlines)
pixWrite("hlinesclean.png", line_pix, IFF_PNG);
ICOORD vertical;
vertical.set_with_shrink(vertical_x, vertical_y);
TabVector::MergeSimilarTabVectors(vertical, vectors, NULL);
// Iterate the vectors to flip them.
TabVector_IT h_it(vectors);
for (h_it.mark_cycle_pt(); !h_it.cycled_list(); h_it.forward()) {
h_it.data()->XYFlip();
}
}
pixDestroy(&line_pix);
#endif
}
// Finds vertical line objects in the given pix.
// Uses the given resolution to determine size thresholds instead of any
// that may be present in the pix.
// The output vertical_x and vertical_y contain a sum of the output vectors,
// thereby giving the mean vertical direction.
// The output vectors are owned by the list and Frozen (cannot refit) by
// having no boxes, as there is no need to refit or merge separator lines.
void LineFinder::FindVerticalLines(int resolution, Pix* pix,
int* vertical_x, int* vertical_y,
TabVector_LIST* vectors) {
#ifdef HAVE_LIBLEPT
Pix* line_pix;
Boxa* boxes = GetVLineBoxes(resolution, pix, &line_pix);
C_BLOB_LIST line_cblobs;
int width = pixGetWidth(pix);
int height = pixGetHeight(pix);
ConvertBoxaToBlobs(width, height, &boxes, &line_cblobs);
// Make the BLOBNBOXes from the C_BLOBs.
BLOBNBOX_LIST line_bblobs;
C_BLOB_IT blob_it(&line_cblobs);
BLOBNBOX_IT bbox_it(&line_bblobs);
for (blob_it.mark_cycle_pt(); !blob_it.cycled_list(); blob_it.forward()) {
C_BLOB* cblob = blob_it.data();
BLOBNBOX* bblob = new BLOBNBOX(cblob);
bbox_it.add_to_end(bblob);
}
ICOORD bleft(0, 0);
ICOORD tright(width, height);
FindLineVectors(bleft, tright, &line_bblobs, vertical_x, vertical_y, vectors);
if (!vectors->empty()) {
// Some lines were found, so erase the unused blobs from the line image
// and then subtract the line image from the source.
bbox_it.move_to_first();
for (bbox_it.mark_cycle_pt(); !bbox_it.cycled_list(); bbox_it.forward()) {
BLOBNBOX* blob = bbox_it.data();
if (blob->left_tab_type() == TT_UNCONFIRMED) {
const TBOX& box = blob->bounding_box();
Box* pixbox = boxCreate(box.left(), height - box.top(),
box.width(), box.height());
pixClearInRect(line_pix, pixbox);
boxDestroy(&pixbox);
}
}
pixDilateBrick(line_pix, line_pix, 1, 3);
pixSubtract(pix, pix, line_pix);
if (textord_tabfind_show_vlines)
pixWrite("vlinesclean.png", line_pix, IFF_PNG);
ICOORD vertical;
vertical.set_with_shrink(*vertical_x, *vertical_y);
TabVector::MergeSimilarTabVectors(vertical, vectors, NULL);
}
pixDestroy(&line_pix);
#endif
}
