Could a GPU speed up comparing every pixel between two images?

Question

I've implemented the game where the user must spot 5 differences in two side by side images, and I've made the image comparison engine to find the different regions first. The performance is pretty good (4-10 ms to compare 800x600), but I'm aware GPUs have so much power. My question is could a performance gain be realized by using all those cores (just to compare each pixel once)... at the cost of copying the images in. My hunch says it may be worthwhile, but my understanding of GPUs is foggy.

Answer 1

Yes, implementing this process to run on the GPU can result in much faster processing time. The amount of performance increase you get is, as you allude to, related to the size of the images you use. The bigger the images, the faster the GPU will complete the process compared to the CPU.

In the case of processing just two images, with dimensions of 800 x 600, the GPU will still be faster. Relatively, that is a very small amount of memory and can be written to the GPU memory quickly.

The algorithm of performing this process on the GPU is not overly complicated, but assuming a person had no experience of writing code for the graphics card, the cost of learning how to code a GPU is potentially not worth the result of having this algorithm implemented on a GPU. If however, the goal was to learn GPU programming, this could be a good early exercise. I would recommend, to first learn gpu programming, which will take some time and should start with even simpler exercises.