TIFFReader.h

/*
 * Copyright © 2017-2018 Stefan Kebekus <stefan.kebekus@math.uni-freiburg.de>
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 
#ifndef TIFFREADER
#define TIFFREADER 1
 
#include <QImage>
#include <QMutex>
#include <QTemporaryFile>
 

 
class TIFFReader
{
 public:
  explicit TIFFReader(const QString& fileName);

  ~TIFFReader();
  
  bool hasError();
  
  QString error();
  
  quint32 size();
  
  QImage operator[](quint16 pageNumber);
  
 private:
  // Prevents simultaneous write access to the tmpFile and the error message by
  // multiple threads
  QMutex mutex;
 
  // This is a temporary file where a copy of the TIFF is kept. The copy is
  // modified by operator[]
  QTemporaryFile tmpFile;
 
  // This data stream is used to read from tmpFile. Its endian-ness is set in
  // the constructor to match the endian-ness of the TIFF
  QDataStream ioStream;
 
  // List of offsets that specify where in the TIFF file the image directories
  // start.
  QList<quint32> IFDOffsets;
 
  // Error message
  QString _error;
};
 
#endif