コードサンプルを探している人のために:
private static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) >= reqHeight
&& (halfWidth / inSampleSize) >= reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
public static Bitmap decodeSampledBitmapFromUri(Context context, Uri imageUri, int reqWidth, int reqHeight) throws FileNotFoundException {
// Get input stream of the image
final BitmapFactory.Options options = new BitmapFactory.Options();
InputStream iStream = context.getContentResolver().openInputStream(imageUri);
// First decode with inJustDecodeBounds=true to check dimensions
options.inJustDecodeBounds = true;
BitmapFactory.decodeStream(iStream, null, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeStream(iStream, null, options);
}