Android-将一张图片插入另一张图片的透明像素

Question

In Android, I'm attempting to layer two images (In this case, Bitmap objects) in a FrameLayout. One image is placed on top, with the other image inserted below it at that image's first transparent pixel.

Currently, I'm attempting the following using Bitmap.getPixel() to locate the transparent pixel:

for (int i = 0; i < image_count; i++)
{
    //load page from internal memory
    topImages[i] = getImage("p"+i+".png");
    for (int x = 0; x < topImages[i].getWidth(); x++)
    {
        for (int y = 0; y < topImages[i].getHeight(); y++)
        {
            if (topImages[i].getPixel(x, y) == Color.TRANSPARENT)
            {
                bottomX[i] = x;
                bottomY[i] = y;
                break;
            }
        }
    }
}

I then add the images to a Frame Layout, using two ImageViews, and use these values to position the lower image:

bottomView.setTranslationX(bottomX[position]);
bottomView.setTranslationY(bottomY[position]);

However, the placement of the bottom image is always inaccurate, usually by a margin down and to the right that is different (but always the same) for each given image. I've also tried setX() and setY() , as well as using parameters to set the TOP and LEFT values similarly, with the same results). What can I do to ensure that the placement is always consistent, with the image's top-left at (or close to) the first transparent pixel?

Answer 1

If you want to only display the images, you can add them as different frames in FrameLayout. In your xml, first declare the one you want to show as transparent pixels, then declare the one which will have transparent pixels.