// Helper gets the image of a rectangle, using the block.re_rotation() if
// needed to get to the image, and rotating the result back to horizontal
// layout. (CJK characters will be on their left sides) The vertical text flag
// is set in the returned ImageData if the text was originally vertical, which
// can be used to invoke a different CJK recognition engine. The revised_box
// is also returned to enable calculation of output bounding boxes.
ImageData* Tesseract::GetRectImage(const TBOX& box, const BLOCK& block,
int padding, TBOX* revised_box) const {
TBOX wbox = box;
wbox.pad(padding, padding);
*revised_box = wbox;
// Number of clockwise 90 degree rotations needed to get back to tesseract
// coords from the clipped image.
int num_rotations = 0;
if (block.re_rotation().y() > 0.0f)
num_rotations = 1;
else if (block.re_rotation().x() < 0.0f)
num_rotations = 2;
else if (block.re_rotation().y() < 0.0f)
num_rotations = 3;
// Handle two cases automatically: 1 the box came from the block, 2 the box
// came from a box file, and refers to the image, which the block may not.
if (block.bounding_box().major_overlap(*revised_box))
revised_box->rotate(block.re_rotation());
// Now revised_box always refers to the image.
// BestPix is never colormapped, but may be of any depth.
Pix* pix = BestPix();
int width = pixGetWidth(pix);
int height = pixGetHeight(pix);
TBOX image_box(0, 0, width, height);
// Clip to image bounds;
*revised_box &= image_box;
if (revised_box->null_box()) return NULL;
Box* clip_box = boxCreate(revised_box->left(), height - revised_box->top(),
revised_box->width(), revised_box->height());
Pix* box_pix = pixClipRectangle(pix, clip_box, NULL);
if (box_pix == NULL) return NULL;
boxDestroy(&clip_box);
if (num_rotations > 0) {
Pix* rot_pix = pixRotateOrth(box_pix, num_rotations);
pixDestroy(&box_pix);
box_pix = rot_pix;
}
// Convert sub-8-bit images to 8 bit.
int depth = pixGetDepth(box_pix);
if (depth < 8) {
Pix* grey;
grey = pixConvertTo8(box_pix, false);
pixDestroy(&box_pix);
box_pix = grey;
}
bool vertical_text = false;
if (num_rotations > 0) {
// Rotated the clipped revised box back to internal coordinates.
FCOORD rotation(block.re_rotation().x(), -block.re_rotation().y());
revised_box->rotate(rotation);
if (num_rotations != 2)
vertical_text = true;
}
return new ImageData(vertical_text, box_pix);
}
// Build the projection profile given the input_block containing lists of
// blobs, a rotation to convert to image coords,
// and a full-resolution nontext_map, marking out areas to avoid.
// During construction, we have the following assumptions:
// The rotation is a multiple of 90 degrees, ie no deskew yet.
// The blobs have had their left and right rules set to also limit
// the range of projection.
void TextlineProjection::ConstructProjection(TO_BLOCK* input_block,
const FCOORD& rotation,
Pix* nontext_map) {
pixDestroy(&pix_);
TBOX image_box(0, 0, pixGetWidth(nontext_map), pixGetHeight(nontext_map));
x_origin_ = 0;
y_origin_ = image_box.height();
int width = (image_box.width() + scale_factor_ - 1) / scale_factor_;
int height = (image_box.height() + scale_factor_ - 1) / scale_factor_;
pix_ = pixCreate(width, height, 8);
ProjectBlobs(&input_block->blobs, rotation, image_box, nontext_map);
ProjectBlobs(&input_block->large_blobs, rotation, image_box, nontext_map);
Pix* final_pix = pixBlockconv(pix_, 1, 1);
// Pix* final_pix = pixBlockconv(pix_, 2, 2);
pixDestroy(&pix_);
pix_ = final_pix;
}
