/////////////////////////////////////////////////////////////////////// // File: associate.h // Description: Structs, classes, typedefs useful for the segmentation // search. Functions for scoring segmentation paths according // to their character widths, gap widths and seam cuts. // Author: Daria Antonova // Created: Mon Mar 8 11:26:43 PDT 2010 // // (C) Copyright 2010, 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. // /////////////////////////////////////////////////////////////////////// #ifndef ASSOCIATE_H #define ASSOCIATE_H #include "blobs.h" #include "elst.h" #include "ratngs.h" #include "seam.h" #include "split.h" class WERD_RES; namespace tesseract { // Statisitcs about character widths, gaps and seams. struct AssociateStats { AssociateStats() { Clear(); } void Clear() { shape_cost = 0.0f; bad_shape = false; full_wh_ratio = 0.0f; full_wh_ratio_total = 0.0f; full_wh_ratio_var = 0.0f; bad_fixed_pitch_right_gap = false; bad_fixed_pitch_wh_ratio = false; gap_sum = 0; } void Print() { tprintf("AssociateStats: s(%g %d)\n", shape_cost, bad_shape); } float shape_cost; // cost of blob shape bool bad_shape; // true if the shape of the blob is unacceptable float full_wh_ratio; // width-to-hight ratio + gap on the right float full_wh_ratio_total; // sum of width-to-hight ratios // on the path terminating at this blob float full_wh_ratio_var; // variance of full_wh_ratios on the path bool bad_fixed_pitch_right_gap; // true if there is no gap before // the blob on the right bool bad_fixed_pitch_wh_ratio; // true if the blobs has width-to-hight // ratio > kMaxFixedPitchCharAspectRatio int gap_sum; // sum of gaps within the blob }; // Utility functions for scoring segmentation paths according to their // character widths, gap widths, seam characteristics. class AssociateUtils { public: static const float kMaxFixedPitchCharAspectRatio; static const float kMinGap; // Returns outline length of the given blob is computed as: // rating_cert_scale * rating / certainty // Since from Wordrec::SegSearch() in segsearch.cpp // rating_cert_scale = -1.0 * getDict().certainty_scale / rating_scale // And from Classify::ConvertMatchesToChoices() in adaptmatch.cpp // Rating = Certainty = next.rating // Rating *= rating_scale * Results->BlobLength // Certainty *= -(getDict().certainty_scale) static inline float ComputeOutlineLength(float rating_cert_scale, const BLOB_CHOICE &b) { return rating_cert_scale * b.rating() / b.certainty(); } static inline float ComputeRating(float rating_cert_scale, float cert, int width) { return static_cast(width) * cert / rating_cert_scale; } // Computes character widths, gaps and seams stats given the // AssociateStats of the path so far, col, row of the blob that // is being added to the path, and WERD_RES containing information // about character widths, gaps and seams. // Fills associate_cost with the combined shape, gap and seam cost // of adding a unichar from (col, row) to the path (note that since // this function could be used to compute the prioritization for // pain points, (col, row) entry might not be classified yet; thus // information in the (col, row) entry of the ratings matrix is not used). // // Note: the function assumes that word_res, stats and // associate_cost pointers are not nullptr. static void ComputeStats(int col, int row, const AssociateStats *parent_stats, int parent_path_length, bool fixed_pitch, float max_char_wh_ratio, WERD_RES *word_res, bool debug, AssociateStats *stats); // Returns the width cost for fixed-pitch text. static float FixedPitchWidthCost(float norm_width, float right_gap, bool end_pos, float max_char_wh_ratio); // Returns the gap cost for fixed-pitch text (penalizes vertically // overlapping components). static inline float FixedPitchGapCost(float norm_gap, bool end_pos) { return (norm_gap < 0.05 && !end_pos) ? 5.0f : 0.0f; } }; } // namespace tesseract #endif