src/com/owncloud/android/utils/BitmapUtils.java

   1 /* ownCloud Android client application
   2  *   Copyright (C) 2012-2014 ownCloud Inc.
   3  *
   4  *   This program is free software: you can redistribute it and/or modify
   5  *   it under the terms of the GNU General Public License version 2,
   6  *   as published by the Free Software Foundation.
   7  *
   8  *   This program is distributed in the hope that it will be useful,
   9  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  *   GNU General Public License for more details.
  12  *
  13  *   You should have received a copy of the GNU General Public License
  14  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  *
  16  */
  17 package com.owncloud.android.utils;
  18
  19 import com.owncloud.android.lib.common.utils.Log_OC;
  20
  21 import android.graphics.Bitmap;
  22 import android.graphics.BitmapFactory;
  23 import android.graphics.Matrix;
  24 import android.graphics.BitmapFactory.Options;
  25 import android.media.ExifInterface;
  26
  27 /**
  28  * Utility class with methods for decoding Bitmaps.
  29  *
  30  * @author David A. Velasco
  31  */
  32 public class BitmapUtils {
  33
  34
  35     /**
  36      * Decodes a bitmap from a file containing it minimizing the memory use, known that the bitmap
  37      * will be drawn in a surface of reqWidth x reqHeight
  38      *
  39      * @param srcPath       Absolute path to the file containing the image.
  40      * @param reqWidth      Width of the surface where the Bitmap will be drawn on, in pixels.
  41      * @param reqHeight     Height of the surface where the Bitmap will be drawn on, in pixels.
  42      * @return
  43      */
  44     public static Bitmap decodeSampledBitmapFromFile(String srcPath, int reqWidth, int reqHeight) {
  45
  46         // set desired options that will affect the size of the bitmap
  47         final Options options = new Options();
  48         options.inScaled = true;
  49         options.inPurgeable = true;
  50         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.GINGERBREAD_MR1) {
  51             options.inPreferQualityOverSpeed = false;
  52         }
  53         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB) {
  54             options.inMutable = false;
  55         }
  56
  57         // make a false load of the bitmap to get its dimensions
  58         options.inJustDecodeBounds = true;
  59
  60         BitmapFactory.decodeFile(srcPath, options);
  61
  62         // calculate factor to subsample the bitmap
  63         options.inSampleSize = calculateSampleFactor(options, reqWidth, reqHeight);
  64
  65         // decode bitmap with inSampleSize set
  66         options.inJustDecodeBounds = false;
  67         return BitmapFactory.decodeFile(srcPath, options);
  68
  69     }
  70
  71
  72     /**
  73      * Calculates a proper value for options.inSampleSize in order to decode a Bitmap minimizing
  74      * the memory overload and covering a target surface of reqWidth x reqHeight if the original
  75      * image is big enough.
  76      *
  77      * @param options       Bitmap decoding options; options.outHeight and options.inHeight should
  78      *                      be set.
  79      * @param reqWidth      Width of the surface where the Bitmap will be drawn on, in pixels.
  80      * @param reqHeight     Height of the surface where the Bitmap will be drawn on, in pixels.
  81      * @return              The largest inSampleSize value that is a power of 2 and keeps both
  82      *                      height and width larger than reqWidth and reqHeight.
  83      */
  84     private static int calculateSampleFactor(Options options, int reqWidth, int reqHeight) {
  85
  86         final int height = options.outHeight;
  87         final int width = options.outWidth;
  88         int inSampleSize = 1;
  89
  90         if (height > reqHeight || width > reqWidth) {
  91             final int halfHeight = height / 2;
  92             final int halfWidth = width / 2;
  93
  94             while ((halfHeight / inSampleSize) > reqHeight
  95                     && (halfWidth / inSampleSize) > reqWidth) {
  96                 inSampleSize *= 2;
  97             }
  98         }
  99
 100         return inSampleSize;
 101     }
 102
 103     /**
 104      * Rotate bitmap according to EXIF orientation.
 105      * Cf. http://www.daveperrett.com/articles/2012/07/28/exif-orientation-handling-is-a-ghetto/
 106      * @param bitmap Bitmap to be rotated
 107      * @param storagePath Path to source file of bitmap. Needed for EXIF information.
 108      * @return correctly EXIF-rotated bitmap
 109      */
 110     public static Bitmap rotateImage(Bitmap bitmap, String storagePath){
 111         Bitmap resultBitmap = bitmap;
 112
 113         try
 114         {
 115             ExifInterface exifInterface = new ExifInterface(storagePath);
 116             int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);
 117
 118             Matrix matrix = new Matrix();
 119
 120             // 1: nothing to do
 121
 122             // 2
 123             if (orientation == ExifInterface.ORIENTATION_FLIP_HORIZONTAL)
 124             {
 125                 matrix.postScale(-1.0f, 1.0f);
 126             }
 127             // 3
 128             else if (orientation == ExifInterface.ORIENTATION_ROTATE_180)
 129             {
 130                 matrix.postRotate(180);
 131             }
 132             // 4
 133             else if (orientation == ExifInterface.ORIENTATION_FLIP_VERTICAL)
 134             {
 135                 matrix.postScale(1.0f, -1.0f);
 136             }
 137             // 5
 138             else if (orientation == ExifInterface.ORIENTATION_TRANSPOSE)
 139             {
 140                 matrix.postRotate(-90);
 141                 matrix.postScale(1.0f, -1.0f);
 142             }
 143             // 6
 144             else if (orientation == ExifInterface.ORIENTATION_ROTATE_90)
 145             {
 146                 matrix.postRotate(90);
 147             }
 148             // 7
 149             else if (orientation == ExifInterface.ORIENTATION_TRANSVERSE)
 150             {
 151                 matrix.postRotate(90);
 152                 matrix.postScale(1.0f, -1.0f);
 153             }
 154             // 8
 155             else if (orientation == ExifInterface.ORIENTATION_ROTATE_270)
 156             {
 157                 matrix.postRotate(270);
 158             }
 159
 160             // Rotate the bitmap
 161             resultBitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
 162             if (resultBitmap != bitmap) {
 163                 bitmap.recycle();
 164             }
 165         }
 166         catch (Exception exception)
 167         {
 168             Log_OC.e("BitmapUtil", "Could not rotate the image: " + storagePath);
 169         }
 170         return resultBitmap;
 171     }
 172
 173
 174 }