Question

i am loading some bitmap from the gallery using the following code:

 bitmap = (BitmapFactory.decodeFile(picturePath)).copy(Bitmap.Config.ARGB_8888, true);
 bitmap = Bitmap.createScaledBitmap(bitmap, screenWidth, screenHeight, true);
 bitmapCanvas = new Canvas(bitmap);
 invalidate(); // refresh the screen

Question:

It seems that it takes so long time to load an image by first decode fully and copy, and then making scaling to fit for the screen width and height. It really actually does not need to load the pic with full density because I would not let the user to enlarge the imported image anyway.

In that way, are there any method to reduce the load time and RAM? (directly load a scaled-down image) How to further modify the above coding?

Answer 1

just have found the answer for this reducing RAM and load time and avoid outofmemory error from other similar questions.

//get importing bitmap dimension
   Options op = new Options();
   op.inJustDecodeBounds = true;
   Bitmap pic_to_be_imported = BitmapFactory.decodeFile(picturePath, op);
   final int x_pic = op.outWidth;
   final int y_pic = op.outHeight;

//The new size we want to scale to
    final int IMAGE_MAX_SIZE= (int) Math.max(DrawViewWidth, DrawViewHeight);

    int scale = 1;
    if (op.outHeight > IMAGE_MAX_SIZE || op.outWidth > IMAGE_MAX_SIZE) 
    {
        scale = (int)Math.pow(2, (int) Math.round(Math.log(IMAGE_MAX_SIZE / 
               (double) Math.max(op.outHeight, op.outWidth)) / Math.log(0.5)));
    }

    final BitmapFactory.Options o2 = new BitmapFactory.Options();
    o2.inSampleSize = scale;        

//Import the file using the o2 options: inSampleSized
    bitmap = (BitmapFactory.decodeFile(picturePath, o2));
    bitmap = bitmap.copy(Bitmap.Config.ARGB_8888, true);