Android Open Source - PictureMap Image Utilities

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License

The source code is released under:

GNU General Public License

Java Source Code

/* Copyright (c) 2009 Ari Pollak <aripollak@gmail.com>
/*from  w ww . ja  va2  s.com*/
   This file is part of Picture Map.

   Picture Map 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.

   Picture Map 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 Picture Map.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.aripollak.picturemap;

import java.io.File;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;

import com.drewChanged.imaging.jpeg.JpegMetadataReader;
import com.drewChanged.imaging.jpeg.JpegProcessingException;
import com.drewChanged.lang.Rational;
import com.drewChanged.metadata.Directory;
import com.drewChanged.metadata.Metadata;
import com.drewChanged.metadata.MetadataException;
import com.drewChanged.metadata.exif.ExifDirectory;
import com.drewChanged.metadata.exif.GpsDirectory;
import com.drewChanged.metadata.jpeg.JpegDirectory;
import com.google.android.maps.GeoPoint;

public class ImageUtilities {
  static final String TAG = "ImageUtilities"; 
  
  /**
   * @param imageLocation
   * @return null if reading failed, the populated Metadata object otherwise
   */
  public static Metadata readMetadata(String imageLocation) {
    if (!(imageLocation.toLowerCase().endsWith(".jpg") || 
        imageLocation.toLowerCase().endsWith(".jpeg"))) {
      return null;
    }
    File file = new File(imageLocation);
    try {
      return JpegMetadataReader.readMetadata(file);
    } catch (JpegProcessingException e) {
      //e.printStackTrace();
      return null;
    } catch (NullPointerException e) {
      //e.printStackTrace();
      return null;
    }
  }
  /** Try to read the specified image and get a Point from the 
   *  location info inside.
   *  @param Metadata populated image metadata
   *  @return null if we couldn't get a proper location
   */
  public static GeoPoint getGPSInfo(Metadata metadata) {    
    int latE6 = 0;
    int lonE6 = 0;
    
    try {
      Directory gpsDirectory = metadata.getDirectory(GpsDirectory.class);
      if (!gpsDirectory.containsTag(GpsDirectory.TAG_GPS_LATITUDE))
        return null;
      
      Rational[] temp;
      char reference;
      int degrees;
      float minutes;
      float seconds;
      
      // Read latitude reference (N or S)
      reference = (char) gpsDirectory.getInt(GpsDirectory.TAG_GPS_LATITUDE_REF);
      if (reference != 'N' && reference != 'S') {
        return null;
      }
      // Read latitude
      temp = gpsDirectory.getRationalArray(GpsDirectory.TAG_GPS_LATITUDE);
      degrees = temp[0].intValue();
      minutes = temp[1].floatValue();
      seconds = temp[2].floatValue();
      latE6 = degrees * (int)1E6;
      latE6 += (((minutes * 60.0) + seconds) / 3600f) * 1E6;
      latE6 *= (reference == 'N') ? 1 : -1;
      
      // Read longitude reference (W or E)
      reference = (char) gpsDirectory.getInt(GpsDirectory.TAG_GPS_LONGITUDE_REF);
      if (reference != 'E' && reference != 'W') {
        return null;
      }
      // Read latitude
      temp = gpsDirectory.getRationalArray(GpsDirectory.TAG_GPS_LONGITUDE);
      degrees = temp[0].intValue();
      minutes = temp[1].floatValue();
      seconds = temp[2].floatValue();
      lonE6 = degrees * (int)1E6;
      lonE6 += (((minutes * 60.0) + seconds) / 3600f) * 1E6;
      lonE6 *= (reference == 'E') ? 1 : -1;
    } catch (MetadataException e) {
      //e.printStackTrace();
      return null;
    }
    return new GeoPoint(latE6, lonE6);
  }
  
  /** Try to get a thumbnail from the specified image.
   * @param metadata populated image metadata
   * @param imageLocation full path to image file
   * @param maxDimension maximum width or height, in pixels */ 
  public static Bitmap getThumb(Metadata metadata, String imageLocation,
        int maxDimension) {
    try {
      int width = 0, height = 0;
      Bitmap decoded = null;
      Directory jpegDirectory = metadata.getDirectory(JpegDirectory.class);
      if (!jpegDirectory.containsTag(JpegDirectory.TAG_JPEG_IMAGE_WIDTH) || 
          !jpegDirectory.containsTag(JpegDirectory.TAG_JPEG_IMAGE_HEIGHT))
        return null;
      
      width = jpegDirectory.getInt(JpegDirectory.TAG_JPEG_IMAGE_WIDTH);
      height = jpegDirectory.getInt(JpegDirectory.TAG_JPEG_IMAGE_HEIGHT);
      
      // Make sure we keep the aspect ratio, with a maximum edge of maxDimension
      float factor = Math.max(width / (float)maxDimension, height / (float)maxDimension);
      int scaledWidth = Math.max(1, (int)(width / factor));
      int scaledHeight = Math.max(1, (int)(height / factor));
      // First subsample the image without loading  into memory,
      // then scale it to exactly the size we want
      BitmapFactory.Options opts = new BitmapFactory.Options();
        opts.inSampleSize = (int) factor;
      decoded = BitmapFactory.decodeFile(imageLocation, opts);
        return Bitmap.createScaledBitmap(
            decoded, scaledWidth, scaledHeight, true);
    } catch (MetadataException e) {
      //e.printStackTrace();
      return null;
    } catch (NullPointerException e) {
      Log.d(TAG, "Couldn't create thumbnail for " + imageLocation);
      return null;
    }
  }
}

Java Source Code List

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