携帯電話のカメラ (8 メガピクセル) で作成した大きな画像を回転させようとしています。ソース Bitmap から回転された Matrix を持つ Bitmap.createBitmap だけで、OutOfMemoryError が発生します。そのため、回転した部分に分割し、それらを再び単一の回転した画像に結合して、2 つの大きなビットマップをメモリに保持しないようにしていますが、Samsung S3 でも最大 10 秒かかります。これを行う他の方法はありますか？
public static void rotateImage(File file)
throws FileNotFoundException {
long time = System.currentTimeMillis();
List<File> fileList = new ArrayList<File>();
// For the number of rows and columns
int rowsCols = 3;
Matrix matrix = new Matrix();
matrix.postRotate(-90);
int chunkHeight, chunkWidth;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(file), null, options);
int height = options.outHeight;
int width = options.outWidth;
chunkHeight = height / rowsCols;
chunkWidth = width / rowsCols;
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = 1;
o2.inPurgeable = true;
o2.inInputShareable = true;
o2.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bitmap = BitmapFactory.decodeStream(new FileInputStream(file),
null, o2);
// Cut the small rotated pieces and save to the files
int yCoord = 0;
for (int y = 0; y < rowsCols; y++) {
int xCoord = 0;
for (int x = 0; x < rowsCols; x++) {
split(chunkHeight, chunkWidth, yCoord, x, xCoord, y, bitmap,
matrix, fileList);
xCoord += chunkWidth;
}
yCoord += chunkHeight;
}
bitmap.recycle();
Bitmap rotatedBitmap = Bitmap.createBitmap(height, width,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(rotatedBitmap);
// Combine the small pieces into the one output canvas
int xCoord;
xCoord = 0;
for (int x = 0; x < rowsCols; x++) {
yCoord = 0;
for (int y = 0; y < rowsCols; y++) {
combineIntoCanvas(o2, canvas, xCoord, yCoord, fileList);
yCoord -= chunkWidth;
}
xCoord += chunkHeight;
}
//Save the bitmap to the file
rotatedBitmap.compress(Bitmap.CompressFormat.JPEG, 90,
new FileOutputStream(file, false));
rotatedBitmap.recycle();
Log.add("combined in " + (System.currentTimeMillis() - time));
}
private static void combineIntoCanvas(BitmapFactory.Options o2,
Canvas canvas, int xCoord, int yCoord, List<File> fileList)
throws FileNotFoundException {
File file = fileList.get(0);
Bitmap bitmap = BitmapFactory.decodeStream(new FileInputStream(file),
null, o2);
canvas.drawBitmap(bitmap, xCoord, yCoord, null);
bitmap.recycle();
file.delete();
fileList.remove(0);
}
private static void split(int chunkHeight, int chunkWidth, int yCoord,
int x, int xCoord, int y, Bitmap bitmap, Matrix matrix,
List<File> fileList) throws FileNotFoundException {
Bitmap pieceOfBitmap = Bitmap.createBitmap(bitmap, xCoord, yCoord,
chunkWidth, chunkHeight, matrix, true);
File splitFile = new File(Globals.IMAGE_BASE_GALLERY_FOLDER() + "temp"
+ x + "_" + y + "." + "jpg");
fileList.add(splitFile);
pieceOfBitmap.compress(Bitmap.CompressFormat.PNG, 0,
new FileOutputStream(splitFile, false));
pieceOfBitmap.recycle();
}