Computer Vision without Image Processing

[faust1706]

Say I have a gray scale image, 640x480 pixels, like this image: I am thinking about training a neural network, with the input of each pixel, to calculate distance. In my training data, I would load in thousands of images with corresponding distances.. I think this would be really cool way of doing computer vision to find the distance to a target. The question arises as to how quick it is and computational heavy it will be. Thoughts?