use arbitrary image

Use any image like those from  [here](https://www.google.com/search?q=depth+map+thumbs+up&espv=2&biw=1348&bih=880&source=lnms&tbm=isch&sa=X&ei=2x-CVMuXEsTloASIjYCwCA&ved=0CAYQ_AUoAQ#q=depthmap+thumbs+up&tbm=isch&tbs=ic:gray&imgdii=_)