I am using a linear layout and frame layout. In the linear layout I keep an image as background and in the frame layout I keep an imageView. In that imageView I give an image.>
Try this:
ImageView myImage = (ImageView) findViewById(R.id.myImage);
myImage.setAlpha(127); //value: [0-255]. Where 0 is fully transparent and 255 is fully opaque.
Note: setAlpha(int) is deprecated in favor of setAlpha(float) where 0 is fully transparent and 1 is fully opaque. Use it like: myImage.setAlpha(0.5f)