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4897796d57
Use macro names as suggested by the Google C++ Style Guide (https://google.github.io/styleguide/cppguide.html#The__define_Guard). Signed-off-by: Stefan Weil <sw@weilnetz.de>
151 lines
6.7 KiB
C++
151 lines
6.7 KiB
C++
///////////////////////////////////////////////////////////////////////
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// File: linefind.h
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// Description: Class to find vertical lines in an image and create
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// a corresponding list of empty blobs.
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// Author: Ray Smith
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// Created: Thu Mar 20 09:49:01 PDT 2008
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//
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// (C) Copyright 2008, Google Inc.
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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///////////////////////////////////////////////////////////////////////
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#ifndef TESSERACT_TEXTORD_LINEFIND_H_
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#define TESSERACT_TEXTORD_LINEFIND_H_
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struct Boxa;
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struct Pix;
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struct Pixa;
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class C_BLOB_LIST;
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class BLOBNBOX_LIST;
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class ICOORD;
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namespace tesseract {
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class TabVector_LIST;
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/**
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* The LineFinder class is a simple static function wrapper class that mainly
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* exposes the FindVerticalLines function.
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*/
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class LineFinder {
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public:
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/**
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* Finds vertical and horizontal line objects in the given pix and removes
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* them.
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*
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* Uses the given resolution to determine size thresholds instead of any
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* that may be present in the pix.
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*
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* The output vertical_x and vertical_y contain a sum of the output vectors,
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* thereby giving the mean vertical direction.
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*
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* If pix_music_mask != NULL, and music is detected, a mask of the staves
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* and anything that is connected (bars, notes etc.) will be returned in
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* pix_music_mask, the mask subtracted from pix, and the lines will not
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* appear in v_lines or h_lines.
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*
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* The output vectors are owned by the list and Frozen (cannot refit) by
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* having no boxes, as there is no need to refit or merge separator lines.
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*
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* The detected lines are removed from the pix.
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*/
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static void FindAndRemoveLines(int resolution, bool debug, Pix* pix,
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int* vertical_x, int* vertical_y,
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Pix** pix_music_mask,
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TabVector_LIST* v_lines,
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TabVector_LIST* h_lines);
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/**
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* Converts the Boxa array to a list of C_BLOB, getting rid of severely
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* overlapping outlines and those that are children of a bigger one.
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*
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* The output is a list of C_BLOBs that are owned by the list.
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*
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* The C_OUTLINEs in the C_BLOBs contain no outline data - just empty
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* bounding boxes. The Boxa is consumed and destroyed.
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*/
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static void ConvertBoxaToBlobs(int image_width, int image_height,
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Boxa** boxes, C_BLOB_LIST* blobs);
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private:
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// Finds vertical line objects in pix_vline and removes them from src_pix.
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// Uses the given resolution to determine size thresholds instead of any
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// that may be present in the pix.
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// The output vertical_x and vertical_y contain a sum of the output vectors,
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// thereby giving the mean vertical direction.
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// The output vectors are owned by the list and Frozen (cannot refit) by
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// having no boxes, as there is no need to refit or merge separator lines.
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// If no good lines are found, pix_vline is destroyed.
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static void FindAndRemoveVLines(int resolution,
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Pix* pix_intersections,
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int* vertical_x, int* vertical_y,
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Pix** pix_vline, Pix* pix_non_vline,
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Pix* src_pix, TabVector_LIST* vectors);
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// Finds horizontal line objects in pix_vline and removes them from src_pix.
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// Uses the given resolution to determine size thresholds instead of any
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// that may be present in the pix.
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// The output vertical_x and vertical_y contain a sum of the output vectors,
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// thereby giving the mean vertical direction.
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// The output vectors are owned by the list and Frozen (cannot refit) by
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// having no boxes, as there is no need to refit or merge separator lines.
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// If no good lines are found, pix_hline is destroyed.
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static void FindAndRemoveHLines(int resolution,
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Pix* pix_intersections,
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int vertical_x, int vertical_y,
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Pix** pix_hline, Pix* pix_non_hline,
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Pix* src_pix, TabVector_LIST* vectors);
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// Finds vertical lines in the given list of BLOBNBOXes. bleft and tright
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// are the bounds of the image on which the input line_bblobs were found.
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// The input line_bblobs list is const really.
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// The output vertical_x and vertical_y are the total of all the vectors.
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// The output list of TabVector makes no reference to the input BLOBNBOXes.
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static void FindLineVectors(const ICOORD& bleft, const ICOORD& tright,
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BLOBNBOX_LIST* line_bblobs,
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int* vertical_x, int* vertical_y,
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TabVector_LIST* vectors);
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// Most of the heavy lifting of line finding. Given src_pix and its separate
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// resolution, returns image masks:
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// Returns image masks:
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// pix_vline candidate vertical lines.
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// pix_non_vline pixels that didn't look like vertical lines.
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// pix_hline candidate horizontal lines.
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// pix_non_hline pixels that didn't look like horizontal lines.
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// pix_intersections pixels where vertical and horizontal lines meet.
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// pix_music_mask candidate music staves.
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// This function promises to initialize all the output (2nd level) pointers,
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// but any of the returns that are empty will be NULL on output.
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// None of the input (1st level) pointers may be NULL except pix_music_mask,
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// which will disable music detection, and pixa_display, which is for debug.
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static void GetLineMasks(int resolution, Pix* src_pix,
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Pix** pix_vline, Pix** pix_non_vline,
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Pix** pix_hline, Pix** pix_non_hline,
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Pix** pix_intersections, Pix** pix_music_mask,
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Pixa* pixa_display);
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// Returns a list of boxes corresponding to the candidate line segments. Sets
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// the line_crossings member of the boxes so we can later determin the number
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// of intersections touched by a full line.
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static void GetLineBoxes(bool horizontal_lines,
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Pix* pix_lines, Pix* pix_intersections,
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C_BLOB_LIST* line_cblobs,
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BLOBNBOX_LIST* line_bblobs);
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};
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} // namespace tesseract.
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#endif // TESSERACT_TEXTORD_LINEFIND_H_
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