Android渐变图形质量（比例位图）

Question

I want to display a splash screen with an gradient in my app. But the quality of the gradient in the background is pretty bad. So I create a simple radiant gradient to have a closer look.

Edit: Maybe I should have mentioned that I am using BitmapFactory.createScaledBitmap(); and BitmapFactory.decodeStream() (The graphics are in the assets folder.)

Thats the result:

Original *.jpg (Quality 100%)

Screenshot Xperia X10 (I took the screenshot with Eclipse)

Answer 1

You can do it without any jpg file, but using a shape drawable . Create rectangle and provide necessary parmas for gradient tag.

Answer 2

In order to scale a bitmap and keep ARGB_8888 I created a new bitmap in the desired size. Then I use canvas to draw the intrinsic bitmap on the new bitmap with drawBitmap . This method allows me to scale the bitmap before I draw it on the new bitmap.

inputStream = assetManager.open(path);
originalBitmap = BitmapFactory.decodeStream(inputStream, null, opts);

Bitmap resizedBitmap = Bitmap.createBitmap(desiredX, desiredY, Config.ARGB_8888);

Canvas canvas = new Canvas(resizedBitmap);
canvas.drawBitmap(originalBitmap, null, new Rect(0, 0, desiredX, desiredY), null);

inputStream.close();
return resizedBitmap;