// Build a ragged TabVector by copying another's direction, shifting it
// to match the given blob, and making its initial extent the height
// of the blob, but its extended bounds from the bounds of the original.
TabVector::TabVector(const TabVector& src, TabAlignment alignment,
const ICOORD& vertical_skew, BLOBNBOX* blob)
: extended_ymin_(src.extended_ymin_), extended_ymax_(src.extended_ymax_),
sort_key_(0), percent_score_(0), mean_width_(0),
needs_refit_(true), needs_evaluation_(true), intersects_other_lines_(false),
alignment_(alignment),
top_constraints_(NULL), bottom_constraints_(NULL) {
BLOBNBOX_C_IT it(&boxes_);
it.add_to_end(blob);
TBOX box = blob->bounding_box();
if (IsLeftTab()) {
startpt_ = box.botleft();
endpt_ = box.topleft();
} else {
startpt_ = box.botright();
endpt_ = box.topright();
}
sort_key_ = SortKey(vertical_skew,
(startpt_.x() + endpt_.x()) / 2,
(startpt_.y() + endpt_.y()) / 2);
if (textord_debug_tabfind > 3)
Print("Constructed a new tab vector:");
}
/**
* Sets up auto page segmentation, determines the orientation, and corrects it.
* Somewhat arbitrary chunk of functionality, factored out of AutoPageSeg to
* facilitate testing.
* photo_mask_pix is a pointer to a NULL pointer that will be filled on return
* with the leptonica photo mask, which must be pixDestroyed by the caller.
* to_blocks is an empty list that will be filled with (usually a single)
* block that is used during layout analysis. This ugly API is required
* because of the possibility of a unlv zone file.
* TODO(rays) clean this up.
* See AutoPageSeg for other arguments.
* The returned ColumnFinder must be deleted after use.
*/
ColumnFinder* Tesseract::SetupPageSegAndDetectOrientation(
bool single_column, bool osd, bool only_osd,
BLOCK_LIST* blocks, Tesseract* osd_tess, OSResults* osr,
TO_BLOCK_LIST* to_blocks, Pix** photo_mask_pix, Pix** music_mask_pix) {
int vertical_x = 0;
int vertical_y = 1;
TabVector_LIST v_lines;
TabVector_LIST h_lines;
ICOORD bleft(0, 0);
ASSERT_HOST(pix_binary_ != NULL);
if (tessedit_dump_pageseg_images) {
pixWrite("tessinput.png", pix_binary_, IFF_PNG);
}
// Leptonica is used to find the rule/separator lines in the input.
LineFinder::FindAndRemoveLines(source_resolution_,
textord_tabfind_show_vlines, pix_binary_,
&vertical_x, &vertical_y, music_mask_pix,
&v_lines, &h_lines);
if (tessedit_dump_pageseg_images)
pixWrite("tessnolines.png", pix_binary_, IFF_PNG);
// Leptonica is used to find a mask of the photo regions in the input.
*photo_mask_pix = ImageFind::FindImages(pix_binary_);
if (tessedit_dump_pageseg_images)
pixWrite("tessnoimages.png", pix_binary_, IFF_PNG);
if (single_column)
v_lines.clear();
// The rest of the algorithm uses the usual connected components.
textord_.find_components(pix_binary_, blocks, to_blocks);
TO_BLOCK_IT to_block_it(to_blocks);
// There must be exactly one input block.
// TODO(rays) handle new textline finding with a UNLV zone file.
ASSERT_HOST(to_blocks->singleton());
TO_BLOCK* to_block = to_block_it.data();
TBOX blkbox = to_block->block->bounding_box();
ColumnFinder* finder = NULL;
if (to_block->line_size >= 2) {
finder = new ColumnFinder(static_cast<int>(to_block->line_size),
blkbox.botleft(), blkbox.topright(),
source_resolution_,
&v_lines, &h_lines, vertical_x, vertical_y);
finder->SetupAndFilterNoise(*photo_mask_pix, to_block);
if (equ_detect_) {
equ_detect_->LabelSpecialText(to_block);
}
BLOBNBOX_CLIST osd_blobs;
// osd_orientation is the number of 90 degree rotations to make the
// characters upright. (See osdetect.h for precise definition.)
// We want the text lines horizontal, (vertical text indicates vertical
// textlines) which may conflict (eg vertically written CJK).
int osd_orientation = 0;
bool vertical_text = finder->IsVerticallyAlignedText(to_block, &osd_blobs);
if (osd && osd_tess != NULL && osr != NULL) {
os_detect_blobs(&osd_blobs, osr, osd_tess);
if (only_osd) {
delete finder;
return NULL;
}
osd_orientation = osr->best_result.orientation_id;
double osd_score = osr->orientations[osd_orientation];
double osd_margin = min_orientation_margin * 2;
for (int i = 0; i < 4; ++i) {
if (i != osd_orientation &&
osd_score - osr->orientations[i] < osd_margin) {
osd_margin = osd_score - osr->orientations[i];
}
}
if (osd_margin < min_orientation_margin) {
// The margin is weak.
int best_script_id = osr->best_result.script_id;
bool cjk = (best_script_id == osd_tess->unicharset.han_sid()) ||
(best_script_id == osd_tess->unicharset.hiragana_sid()) ||
(best_script_id == osd_tess->unicharset.katakana_sid());
if (!cjk && !vertical_text && osd_orientation == 2) {
// upside down latin text is improbable with such a weak margin.
tprintf("OSD: Weak margin (%.2f), horiz textlines, not CJK: "
"Don't rotate.\n", osd_margin);
osd_orientation = 0;
} else {
tprintf("OSD: Weak margin (%.2f) for %d blob text block, "
"but using orientation anyway: %d\n",
osd_blobs.length(), osd_margin, osd_orientation);
}
}
}
osd_blobs.shallow_clear();
finder->CorrectOrientation(to_block, vertical_text, osd_orientation);
}
return finder;
}
/**
* Sets up auto page segmentation, determines the orientation, and corrects it.
* Somewhat arbitrary chunk of functionality, factored out of AutoPageSeg to
* facilitate testing.
* photo_mask_pix is a pointer to a NULL pointer that will be filled on return
* with the leptonica photo mask, which must be pixDestroyed by the caller.
* to_blocks is an empty list that will be filled with (usually a single)
* block that is used during layout analysis. This ugly API is required
* because of the possibility of a unlv zone file.
* TODO(rays) clean this up.
* See AutoPageSeg for other arguments.
* The returned ColumnFinder must be deleted after use.
*/
ColumnFinder* Tesseract::SetupPageSegAndDetectOrientation(
PageSegMode pageseg_mode, BLOCK_LIST* blocks, Tesseract* osd_tess,
OSResults* osr, TO_BLOCK_LIST* to_blocks, Pix** photo_mask_pix,
Pix** music_mask_pix) {
int vertical_x = 0;
int vertical_y = 1;
TabVector_LIST v_lines;
TabVector_LIST h_lines;
ICOORD bleft(0, 0);
ASSERT_HOST(pix_binary_ != NULL);
if (tessedit_dump_pageseg_images) {
pixa_debug_.AddPix(pix_binary_, "PageSegInput");
}
// Leptonica is used to find the rule/separator lines in the input.
LineFinder::FindAndRemoveLines(source_resolution_,
textord_tabfind_show_vlines, pix_binary_,
&vertical_x, &vertical_y, music_mask_pix,
&v_lines, &h_lines);
if (tessedit_dump_pageseg_images) {
pixa_debug_.AddPix(pix_binary_, "NoLines");
}
// Leptonica is used to find a mask of the photo regions in the input.
*photo_mask_pix = ImageFind::FindImages(pix_binary_, &pixa_debug_);
if (tessedit_dump_pageseg_images) {
pixa_debug_.AddPix(pix_binary_, "NoImages");
}
if (!PSM_COL_FIND_ENABLED(pageseg_mode)) v_lines.clear();
// The rest of the algorithm uses the usual connected components.
textord_.find_components(pix_binary_, blocks, to_blocks);
TO_BLOCK_IT to_block_it(to_blocks);
// There must be exactly one input block.
// TODO(rays) handle new textline finding with a UNLV zone file.
ASSERT_HOST(to_blocks->singleton());
TO_BLOCK* to_block = to_block_it.data();
TBOX blkbox = to_block->block->bounding_box();
ColumnFinder* finder = NULL;
int estimated_resolution = source_resolution_;
if (source_resolution_ == kMinCredibleResolution) {
// Try to estimate resolution from typical body text size.
int res = IntCastRounded(to_block->line_size * kResolutionEstimationFactor);
if (res > estimated_resolution && res < kMaxCredibleResolution) {
estimated_resolution = res;
tprintf("Estimating resolution as %d\n", estimated_resolution);
}
}
if (to_block->line_size >= 2) {
finder = new ColumnFinder(static_cast<int>(to_block->line_size),
blkbox.botleft(), blkbox.topright(),
estimated_resolution, textord_use_cjk_fp_model,
textord_tabfind_aligned_gap_fraction, &v_lines,
&h_lines, vertical_x, vertical_y);
finder->SetupAndFilterNoise(pageseg_mode, *photo_mask_pix, to_block);
if (equ_detect_) {
equ_detect_->LabelSpecialText(to_block);
}
BLOBNBOX_CLIST osd_blobs;
// osd_orientation is the number of 90 degree rotations to make the
// characters upright. (See osdetect.h for precise definition.)
// We want the text lines horizontal, (vertical text indicates vertical
// textlines) which may conflict (eg vertically written CJK).
int osd_orientation = 0;
bool vertical_text = textord_tabfind_force_vertical_text ||
pageseg_mode == PSM_SINGLE_BLOCK_VERT_TEXT;
if (!vertical_text && textord_tabfind_vertical_text &&
PSM_ORIENTATION_ENABLED(pageseg_mode)) {
vertical_text =
finder->IsVerticallyAlignedText(textord_tabfind_vertical_text_ratio,
to_block, &osd_blobs);
}
if (PSM_OSD_ENABLED(pageseg_mode) && osd_tess != NULL && osr != NULL) {
GenericVector<int> osd_scripts;
if (osd_tess != this) {
// We are running osd as part of layout analysis, so constrain the
// scripts to those allowed by *this.
AddAllScriptsConverted(unicharset, osd_tess->unicharset, &osd_scripts);
for (int s = 0; s < sub_langs_.size(); ++s) {
AddAllScriptsConverted(sub_langs_[s]->unicharset,
osd_tess->unicharset, &osd_scripts);
}
}
os_detect_blobs(&osd_scripts, &osd_blobs, osr, osd_tess);
if (pageseg_mode == PSM_OSD_ONLY) {
delete finder;
return NULL;
}
osd_orientation = osr->best_result.orientation_id;
double osd_score = osr->orientations[osd_orientation];
double osd_margin = min_orientation_margin * 2;
for (int i = 0; i < 4; ++i) {
if (i != osd_orientation &&
osd_score - osr->orientations[i] < osd_margin) {
osd_margin = osd_score - osr->orientations[i];
}
}
int best_script_id = osr->best_result.script_id;
const char* best_script_str =
osd_tess->unicharset.get_script_from_script_id(best_script_id);
bool cjk = best_script_id == osd_tess->unicharset.han_sid() ||
best_script_id == osd_tess->unicharset.hiragana_sid() ||
best_script_id == osd_tess->unicharset.katakana_sid() ||
strcmp("Japanese", best_script_str) == 0 ||
strcmp("Korean", best_script_str) == 0 ||
strcmp("Hangul", best_script_str) == 0;
if (cjk) {
finder->set_cjk_script(true);
}
if (osd_margin < min_orientation_margin) {
// The margin is weak.
if (!cjk && !vertical_text && osd_orientation == 2) {
// upside down latin text is improbable with such a weak margin.
tprintf("OSD: Weak margin (%.2f), horiz textlines, not CJK: "
"Don't rotate.\n", osd_margin);
osd_orientation = 0;
} else {
tprintf(
"OSD: Weak margin (%.2f) for %d blob text block, "
"but using orientation anyway: %d\n",
osd_margin, osd_blobs.length(), osd_orientation);
}
}
}
osd_blobs.shallow_clear();
finder->CorrectOrientation(to_block, vertical_text, osd_orientation);
}
return finder;
}
// Auto page segmentation. Divide the page image into blocks of uniform
// text linespacing and images.
// Width, height and resolution are derived from the input image.
// If the pix is non-NULL, then it is assumed to be the input, and it is
// copied to the image, otherwise the image is used directly.
// The output goes in the blocks list with corresponding TO_BLOCKs in the
// to_blocks list.
// If single_column is true, then no attempt is made to divide the image
// into columns, but multiple blocks are still made if the text is of
// non-uniform linespacing.
int Tesseract::AutoPageSeg(int width, int height, int resolution,
bool single_column, IMAGE* image,
BLOCK_LIST* blocks, TO_BLOCK_LIST* to_blocks) {
int vertical_x = 0;
int vertical_y = 1;
TabVector_LIST v_lines;
TabVector_LIST h_lines;
ICOORD bleft(0, 0);
Boxa* boxa = NULL;
Pixa* pixa = NULL;
// The blocks made by the ColumnFinder. Moved to blocks before return.
BLOCK_LIST found_blocks;
#ifdef HAVE_LIBLEPT
if (pix_binary_ != NULL) {
if (textord_debug_images) {
Pix* grey_pix = pixCreate(width, height, 8);
// Printable images are light grey on white, but for screen display
// they are black on dark grey so the other colors show up well.
if (textord_debug_printable) {
pixSetAll(grey_pix);
pixSetMasked(grey_pix, pix_binary_, 192);
} else {
pixSetAllArbitrary(grey_pix, 64);
pixSetMasked(grey_pix, pix_binary_, 0);
}
AlignedBlob::IncrementDebugPix();
pixWrite(AlignedBlob::textord_debug_pix().string(), grey_pix, IFF_PNG);
pixDestroy(&grey_pix);
}
if (tessedit_dump_pageseg_images)
pixWrite("tessinput.png", pix_binary_, IFF_PNG);
// Leptonica is used to find the lines and image regions in the input.
LineFinder::FindVerticalLines(resolution, pix_binary_,
&vertical_x, &vertical_y, &v_lines);
LineFinder::FindHorizontalLines(resolution, pix_binary_, &h_lines);
if (tessedit_dump_pageseg_images)
pixWrite("tessnolines.png", pix_binary_, IFF_PNG);
ImageFinder::FindImages(pix_binary_, &boxa, &pixa);
if (tessedit_dump_pageseg_images)
pixWrite("tessnoimages.png", pix_binary_, IFF_PNG);
// Copy the Pix to the IMAGE.
image->FromPix(pix_binary_);
if (single_column)
v_lines.clear();
}
#endif
TO_BLOCK_LIST land_blocks, port_blocks;
TBOX page_box;
// The rest of the algorithm uses the usual connected components.
find_components(blocks, &land_blocks, &port_blocks, &page_box);
TO_BLOCK_IT to_block_it(&port_blocks);
ASSERT_HOST(!to_block_it.empty());
for (to_block_it.mark_cycle_pt(); !to_block_it.cycled_list();
to_block_it.forward()) {
TO_BLOCK* to_block = to_block_it.data();
TBOX blkbox = to_block->block->bounding_box();
if (to_block->line_size >= 2) {
// Note: if there are multiple blocks, then v_lines, boxa, and pixa
// are empty on the next iteration, but in this case, we assume
// that there aren't any interesting line separators or images, since
// it means that we have a pre-defined unlv zone file.
ColumnFinder finder(static_cast<int>(to_block->line_size),
blkbox.botleft(), blkbox.topright(),
&v_lines, &h_lines, vertical_x, vertical_y);
if (finder.FindBlocks(height, resolution, single_column,
to_block, boxa, pixa, &found_blocks, to_blocks) < 0)
return -1;
finder.ComputeDeskewVectors(&deskew_, &reskew_);
boxa = NULL;
pixa = NULL;
}
}
#ifdef HAVE_LIBLEPT
boxaDestroy(&boxa);
pixaDestroy(&pixa);
#endif
blocks->clear();
BLOCK_IT block_it(blocks);
// Move the found blocks to the input/output blocks.
block_it.add_list_after(&found_blocks);
if (textord_debug_images) {
// The debug image is no longer needed so delete it.
unlink(AlignedBlob::textord_debug_pix().string());
}
return 0;
}
