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123 lines
4.5 KiB
C++
123 lines
4.5 KiB
C++
/**********************************************************************
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* File: cube_search_object.h
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* Description: Declaration of the Cube Search Object Class
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* Author: Ahmad Abdulkader
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* Created: 2007
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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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// The CubeSearchObject class represents a char_samp (a word bitmap) that is
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// being searched for characters (or recognizeable entities).
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// The Class detects the connected components and peforms an oversegmentation
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// on each ConComp. The result of which is a list of segments that are ordered
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// in reading order.
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// The class provided methods that inquire about the number of segments, the
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// CharSamp corresponding to any segment range and the recognition results
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// of any segment range
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// An object of Class CubeSearchObject is used by the BeamSearch algorithm
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// to recognize a CharSamp into a list of word alternates
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#ifndef CUBE_SEARCH_OBJECT_H
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#define CUBE_SEARCH_OBJECT_H
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#include "search_object.h"
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#include "char_samp.h"
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#include "conv_net_classifier.h"
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#include "cube_reco_context.h"
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#include "allheaders.h"
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namespace tesseract {
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class CubeSearchObject : public SearchObject {
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public:
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CubeSearchObject(CubeRecoContext *cntxt, CharSamp *samp);
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~CubeSearchObject();
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// returns the Segmentation Point count of the CharSamp owned by the class
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int SegPtCnt();
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// Recognize the set of segments given by the specified range and return
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// a list of possible alternate answers
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CharAltList * RecognizeSegment(int start_pt, int end_pt);
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// Returns the CharSamp corresponding to the specified segment range
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CharSamp *CharSample(int start_pt, int end_pt);
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// Returns a leptonica box corresponding to the specified segment range
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Box *CharBox(int start_pt, int end_pt);
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// Returns the cost of having a space before the specified segmentation pt
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int SpaceCost(int seg_pt);
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// Returns the cost of not having a space before the specified
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// segmentation pt
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int NoSpaceCost(int seg_pt);
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// Returns the cost of not having any spaces within the specified range
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// of segmentation points
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int NoSpaceCost(int seg_pt, int end_pt);
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private:
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// Maximum reasonable segment count
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static const int kMaxSegmentCnt = 128;
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// Use cropped samples
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static const bool kUseCroppedChars;
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// reading order flag
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bool rtl_;
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// cached dimensions of char samp
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int left_;
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int itop_;
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int wid_;
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int hgt_;
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// minimum and maximum and possible inter-segment gaps for spaces
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int min_spc_gap_;
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int max_spc_gap_;
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// initialization flag
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bool init_;
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// maximum segments per character: Cached from tuning parameters object
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int max_seg_per_char_;
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// char sample to be processed
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CharSamp *samp_;
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// segment count
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int segment_cnt_;
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// segments of the processed char samp
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ConComp **segments_;
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// Cache data members:
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// There are two caches kept; a CharSamp cache and a CharAltList cache
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// Each is a 2-D array of CharSamp and CharAltList pointers respectively
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// hence the triple pointer.
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CharAltList ***reco_cache_;
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CharSamp ***samp_cache_;
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// Cached costs of space and no-space after every segment. Computed only
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// in phrase mode
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int *space_cost_;
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int *no_space_cost_;
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// init and allocate variables, perform segmentation
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bool Init();
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// Cleanup
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void Cleanup();
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// Perform segmentation of the bitmap by detecting connected components,
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// segmenting each connected component using windowed vertical pixel density
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// histogram and sorting the resulting segments in reading order
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// Returns true on success
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bool Segment();
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// validate the segment ranges.
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inline bool IsValidSegmentRange(int start_pt, int end_pt) {
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return (end_pt > start_pt && start_pt >= -1 && start_pt < segment_cnt_ &&
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end_pt >= 0 && end_pt <= segment_cnt_ &&
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end_pt <= (start_pt + max_seg_per_char_));
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}
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// computes the space and no space costs at gaps between segments
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// return true on success
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bool ComputeSpaceCosts();
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};
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}
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#endif // CUBE_SEARCH_OBJECT_H
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