imageInfo.h

/*
 * Copyright © 2017--2020 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 imageINFO
#define imageINFO 1
 
#include <QImage>
#include <QString>
 
#include "resolution.h"
 

 
class imageInfo
{
 public:

  imageInfo();

  // cppcheck-suppress noExplicitConstructor
  imageInfo(const QImage &image) {
    read(image);
  }

  explicit imageInfo(const QString &fileName) {
    read(fileName);
  }
  
  void clear();

  bool read(const QImage &image);

  bool read(const QString &fileName);

  static QList<imageInfo> readAll(const QString &fileName);
  
  inline bool isEmpty() const {
    return ((widthInPixel == 0) || (heightInPixel == 0));
  };
  
  inline resolution xResolution() const {
    return _xResolution;
  }

  inline resolution yResolution() const {
    return _yResolution;
  }
  
  inline operator QString() const {
    QString result;
    if (!error.isEmpty())
      result += QString("Error: %1; ").arg(error);
    result += QString("Width: %1px; ").arg(widthInPixel);
    result += QString("Height: %1px; ").arg(heightInPixel);
    result += QString("xRes: %1dpi; ").arg(_xResolution.get(resolution::dpi));
    result += QString("yRes: %1dpi; ").arg(_yResolution.get(resolution::dpi));
    result += QString("color components: %1").arg(numberOfColorComponents);
    return result;
  }
  
  QString error;
  
  quint32 heightInPixel{};
  
  quint8  numberOfColorComponents{};
  
  quint32 widthInPixel{};
  
  resolution _xResolution;
  
  resolution _yResolution;
  
 private:
  /* Reads info from a JPEG file, without decoding the image data.  The method
     is therefore rather inexpensive.  In case of error, an error message is
     saved in the 'error' member,  all other members are set to their default
     values, and 'false' is returned.  Returns 'true' otherwise.
  */
  bool readJPEG(const QString &fileName);
 
  /* Reads info from a JPEG2000 file (in JP2 or JPX format), without decoding
     the image data.  The method is therefore rather inexpensive.  In case of
     error, an error message is saved in the 'error' member, all other members
     are set to their default values, and 'false' is returned.  Returns 'true'
     otherwise.
  */
  bool readJP2(const QString &fileName);
};
 
#endif