well, basically it uses information from previous frames in order to create a new frame at a high pixel count while using less calculations, but it was never fully explained by insomniac how does it work. (n4g.com)
It interpolates information from previous frames into the current frame to make a resolution higher than the actual frame being rendered. (n4g.com)
Stewen embraces such preludes — the flesh - like tones of the aging paper, text revealing translation errors, wear from previous framing for use as inexpensive wall decoration — often restoring the paper after tearing out the images and before beginning to draw. (tanyabonakdargallery.com)