Pensieve header: Progressive scanning of a photo.

img=ImageData@Import@"C:/drorbn/AcademicPensieve/Classes/17-1350-AKT/CP8.png";
SlideView@Table[bs=2^(8-k);
Graphics[Raster[Reverse[Total[Partition[img, {bs,bs}], {3,4}]/bs^2.]],
ImageSize -> 256, ImagePadding -> None, PlotRangePadding -> None],{k,0,8}]