1. A computer implemented method for applying blur to an application window comprising: calculating, with a processor, a velocity vector for each corner of the application window from a first frame to a second frame stored in a computer memory; and for each pixel in the application window: calculating, with the processor, a first velocity vector for the pixel based, at least in part, on an extrapolation of the velocity vectors for each corner, wherein the calculation for a respective pixel is not performed if it is located in a hidden or obscured portion of the application window; and blurring the pixel according to the first velocity vector, wherein the blurring of the pixel comprises placing a plurality of blur samples along the first velocity vector for the pixel.