Compare the pixel of the two different images, takes too long time

Question

I want to compare the pixel of the two different images. I am comparing the pixel of first image with all the pixels of the second Image. Here is my code stuff:

Answer 1

If you're using API level 12 or above, there's a method called sameAs on Bitmap to do exactly what you're looking for. Otherwise, use getPixels and do something like:

int width = bitmap1.getWidth();
int height = bitmap1.getHeight();
int pixelCount = width * height;
int[] pixels1 = new int[pixelCount];
int[] pixels2 = new int[pixelCount];

bitmap1.getPixels(pixels1, 0, 0, 0, 0, width, height);
bitmap2.getPixels(pixels2, 0, 0, 0, 0, width, height);

for (int i = 0; i < pixelCount; i++) {
    if (pixels1[i] != pixels2[i]) {
        return false;
    }
}
return true;

Or if you really want to do the counter thing to see how many pixels are the same, go ahead and do that.

Actually, you can probably do something with the buffers too... Maybe something like

int width = bitmap1.getWidth();
int height = bitmap1.getHeight();
int pixelCount = width * height;
IntBuffer buffer1 = IntBuffer.allocate(pixelCount);
IntBuffer buffer2 = IntBuffer.allocate(pixelCount);
bitmap1.copyPixelsToBuffer(buffer1);
bitmap2.copyPixelsToBuffer(buffer2);
int result = buffer1.compareTo(buffer2);

I'm not sure how those two methods compare in performance, but it's something to play around with if you want.