mirror of
https://github.com/tesseract-ocr/tesseract.git
synced 2024-12-18 19:39:24 +08:00
0a9ad20d1c
git-svn-id: https://tesseract-ocr.googlecode.com/svn/trunk@301 d0cd1f9f-072b-0410-8dd7-cf729c803f20
108 lines
4.1 KiB
C++
108 lines
4.1 KiB
C++
///////////////////////////////////////////////////////////////////////
|
|
// File: bbgrid.cpp
|
|
// Description: Class to hold BLOBNBOXs in a grid for fast access
|
|
// to neighbours.
|
|
// Author: Ray Smith
|
|
// Created: Wed Jun 06 17:22:01 PDT 2007
|
|
//
|
|
// (C) Copyright 2007, Google Inc.
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
//
|
|
///////////////////////////////////////////////////////////////////////
|
|
|
|
#include "bbgrid.h"
|
|
#include "ocrblock.h"
|
|
|
|
namespace tesseract {
|
|
|
|
#ifdef HAVE_LIBLEPT
|
|
// Make a Pix of the correct scaled size for the TraceOutline functions.
|
|
Pix* GridReducedPix(const TBOX& box, int gridsize,
|
|
ICOORD bleft, int* left, int* bottom) {
|
|
// Compute grid bounds of the outline and pad all round by 1.
|
|
int grid_left = (box.left() - bleft.x()) / gridsize - 1;
|
|
int grid_bottom = (box.bottom() - bleft.y()) / gridsize - 1;
|
|
int grid_right = (box.right() - bleft.x()) / gridsize + 1;
|
|
int grid_top = (box.top() - bleft.y()) / gridsize + 1;
|
|
*left = grid_left;
|
|
*bottom = grid_bottom;
|
|
return pixCreate(grid_right - grid_left + 1,
|
|
grid_top - grid_bottom + 1,
|
|
1);
|
|
}
|
|
|
|
// Helper function to return a scaled Pix with one pixel per grid cell,
|
|
// set (black) where the given outline enters the corresponding grid cell,
|
|
// and clear where the outline does not touch the grid cell.
|
|
// Also returns the grid coords of the bottom-left of the Pix, in *left
|
|
// and *bottom, which corresponds to (0, 0) on the Pix.
|
|
// Note that the Pix is used upside-down, with (0, 0) being the bottom-left.
|
|
Pix* TraceOutlineOnReducedPix(C_OUTLINE* outline, int gridsize,
|
|
ICOORD bleft, int* left, int* bottom) {
|
|
TBOX box = outline->bounding_box();
|
|
Pix* pix = GridReducedPix(box, gridsize, bleft, left, bottom);
|
|
int wpl = pixGetWpl(pix);
|
|
l_uint32* data = pixGetData(pix);
|
|
int length = outline->pathlength();
|
|
ICOORD pos = outline->start_pos();
|
|
for (int i = 0; i < length; ++i) {
|
|
int grid_x = (pos.x() - bleft.x()) / gridsize - *left;
|
|
int grid_y = (pos.y() - bleft.y()) / gridsize - *bottom;
|
|
SET_DATA_BIT(data + grid_y * wpl, grid_x);
|
|
pos += outline->step(i);
|
|
}
|
|
return pix;
|
|
}
|
|
#if 0 // Example code shows how to use TraceOutlineOnReducedPix.
|
|
C_OUTLINE_IT ol_it(blob->cblob()->out_list());
|
|
int grid_left, grid_bottom;
|
|
Pix* pix = TraceOutlineOnReducedPix(ol_it.data(), gridsize_, bleft_,
|
|
&grid_left, &grid_bottom);
|
|
grid->InsertPixPtBBox(grid_left, grid_bottom, pix, blob);
|
|
pixDestroy(&pix);
|
|
#endif
|
|
|
|
// As TraceOutlineOnReducedPix above, but on a BLOCK instead of a C_OUTLINE.
|
|
Pix* TraceBlockOnReducedPix(BLOCK* block, int gridsize,
|
|
ICOORD bleft, int* left, int* bottom) {
|
|
TBOX box = block->bounding_box();
|
|
Pix* pix = GridReducedPix(box, gridsize, bleft, left, bottom);
|
|
int wpl = pixGetWpl(pix);
|
|
l_uint32* data = pixGetData(pix);
|
|
ICOORDELT_IT it(block->poly_block()->points());
|
|
for (it.mark_cycle_pt(); !it.cycled_list();) {
|
|
ICOORD pos = *it.data();
|
|
it.forward();
|
|
ICOORD next_pos = *it.data();
|
|
ICOORD line_vector = next_pos - pos;
|
|
int major, minor;
|
|
ICOORD major_step, minor_step;
|
|
line_vector.setup_render(&major_step, &minor_step, &major, &minor);
|
|
int accumulator = major / 2;
|
|
while (pos != next_pos) {
|
|
int grid_x = (pos.x() - bleft.x()) / gridsize - *left;
|
|
int grid_y = (pos.y() - bleft.y()) / gridsize - *bottom;
|
|
SET_DATA_BIT(data + grid_y * wpl, grid_x);
|
|
pos += major_step;
|
|
accumulator += minor;
|
|
if (accumulator >= major) {
|
|
accumulator -= major;
|
|
pos += minor_step;
|
|
}
|
|
}
|
|
}
|
|
return pix;
|
|
}
|
|
#endif
|
|
|
|
} // namespace tesseract.
|
|
|