/src/tesseract/src/classify/mfoutline.h

Source
/******************************************************************************
 ** Filename:    mfoutline.h
 ** Purpose:     Interface spec for fx outline structures
 ** Author:      Dan Johnson
 **
 ** (c) Copyright Hewlett-Packard Company, 1988.
 ** 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 MFOUTLINE_H
#define MFOUTLINE_H

#include "blobs.h"
#include "fpoint.h"
#include "oldlist.h"
#include "params.h"

namespace tesseract {

using MFOUTLINE = LIST;

enum class DIRECTION : uint8_t { north, south, east, west, northeast, northwest, southeast, southwest };

struct MFEDGEPT {
  // Inline functions for manipulating micro-feature outline edge points.

  void ClearMark() {
    ExtremityMark = false;
  }

  void MarkPoint() {
    ExtremityMark = true;
  }

  FPOINT Point;
  float Slope;
  bool Hidden;
  bool ExtremityMark;
  DIRECTION Direction;
  DIRECTION PreviousDirection;
};

enum NORM_METHOD { baseline, character };

/**----------------------------------------------------------------------------
          Macros
----------------------------------------------------------------------------**/
template <typename T>
inline constexpr T AverageOf(T A, T B) {
  return (A + B) / T{2};
}

// Constant for computing the scale factor to use to normalize characters.
constexpr float MF_SCALE_FACTOR = 0.5f / kBlnXHeight;

// Inline functions for manipulating micro-feature outlines.

static inline bool DegenerateOutline(MFOUTLINE Outline) {
  return (Outline == NIL_LIST) || (Outline == Outline->list_rest());
}

static inline MFEDGEPT *PointAt(MFOUTLINE Outline) {
  return reinterpret_cast<MFEDGEPT *>(Outline->first_node());
}

static inline MFOUTLINE NextPointAfter(MFOUTLINE Outline) {
  return Outline->list_rest();
}

static inline void MakeOutlineCircular(MFOUTLINE Outline) {
  set_rest(last(Outline), Outline);
}

/**----------------------------------------------------------------------------
          Public Function Prototypes
----------------------------------------------------------------------------**/
void ComputeBlobCenter(TBLOB *Blob, TPOINT *BlobCenter);

LIST ConvertBlob(TBLOB *Blob);

MFOUTLINE ConvertOutline(TESSLINE *Outline);

void FilterEdgeNoise(MFOUTLINE Outline, float NoiseSegmentLength);

void FindDirectionChanges(MFOUTLINE Outline, float MinSlope, float MaxSlope);

void FreeMFOutline(void *agr); // MFOUTLINE Outline);

void FreeOutlines(LIST Outlines);

void MarkDirectionChanges(MFOUTLINE Outline);

MFOUTLINE NextExtremity(MFOUTLINE EdgePoint);

void NormalizeOutline(MFOUTLINE Outline, float XOrigin);

/*----------------------------------------------------------------------------
          Private Function Prototypes
-----------------------------------------------------------------------------*/
void ChangeDirection(MFOUTLINE Start, MFOUTLINE End, DIRECTION Direction);

// Normalizes the Outline in-place using cn_denorm's local transformation,
// then converts from the integer feature range [0,255] to the clusterer
// feature range of [-0.5, 0.5].
void CharNormalizeOutline(MFOUTLINE Outline, const DENORM &cn_denorm);

void ComputeDirection(MFEDGEPT *Start, MFEDGEPT *Finish, float MinSlope, float MaxSlope);

MFOUTLINE NextDirectionChange(MFOUTLINE EdgePoint);

} // namespace tesseract

#endif

Coverage Report

Created: 2026-09-14 06:59