ocrpara.cpp

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// File:        ocrpara.cpp
// Description: OCR Paragraph Output Type
// Author:      David Eger
// Created:     2010-11-15
//
// (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.
//

#include <cstdio>

#include "ocrpara.h"
#include "host.h"  // For NearlyEqual()

ELISTIZE(PARA)

using tesseract::JUSTIFICATION_LEFT;
using tesseract::JUSTIFICATION_RIGHT;
using tesseract::JUSTIFICATION_CENTER;
using tesseract::JUSTIFICATION_UNKNOWN;

static STRING ParagraphJustificationToString(
    tesseract::ParagraphJustification justification) {
  switch (justification) {
    case JUSTIFICATION_LEFT:
      return "LEFT";
    case JUSTIFICATION_RIGHT:
      return "RIGHT";
    case JUSTIFICATION_CENTER:
      return "CENTER";
    default:
      return "UNKNOWN";
  }
}

bool ParagraphModel::ValidFirstLine(int lmargin, int lindent,
                                    int rindent, int rmargin) const {
  switch (justification_) {
    case JUSTIFICATION_LEFT:
      return NearlyEqual(lmargin + lindent, margin_ + first_indent_,
                         tolerance_);
    case JUSTIFICATION_RIGHT:
      return NearlyEqual(rmargin + rindent, margin_ + first_indent_,
                         tolerance_);
    case JUSTIFICATION_CENTER:
      return NearlyEqual(lindent, rindent, tolerance_ * 2);
    default:
      // shouldn't happen
      return false;
  }
}

bool ParagraphModel::ValidBodyLine(int lmargin, int lindent,
                                   int rindent, int rmargin) const {
  switch (justification_) {
    case JUSTIFICATION_LEFT:
      return NearlyEqual(lmargin + lindent, margin_ + body_indent_,
                         tolerance_);
    case JUSTIFICATION_RIGHT:
      return NearlyEqual(rmargin + rindent, margin_ + body_indent_,
                         tolerance_);
    case JUSTIFICATION_CENTER:
      return NearlyEqual(lindent, rindent, tolerance_ * 2);
    default:
      // shouldn't happen
      return false;
  }
}

bool ParagraphModel::Comparable(const ParagraphModel &other) const {
  if (justification_ != other.justification_)
    return false;
  if (justification_ == JUSTIFICATION_CENTER ||
      justification_ == JUSTIFICATION_UNKNOWN)
    return true;
  int tolerance = (tolerance_ + other.tolerance_) / 4;
  return NearlyEqual(margin_ + first_indent_,
                     other.margin_ + other.first_indent_, tolerance) &&
         NearlyEqual(margin_ + body_indent_,
                     other.margin_ + other.body_indent_, tolerance);
}

STRING ParagraphModel::ToString() const {
  char buffer[200];
  const STRING &alignment = ParagraphJustificationToString(justification_);
  snprintf(buffer, sizeof(buffer),
           "margin: %d, first_indent: %d, body_indent: %d, alignment: %s",
           margin_, first_indent_, body_indent_, alignment.string());
  return STRING(buffer);
}