I have implemented Wei and Levoy's multiresolution synthesis in my program. Since a small window on a coarse level can approximately serve as a large window on a fine level, multiresolution method effectively enables us to use smaller-size windows to synthesize textures.
In my program, I build pyramids for A, A', B, B''. I use a parameter '-min-image-size X' to control the depth of the pyramid. When the original image is downsampled to an image whose width or height is less than X, downsampling is stopped.
The following images compare the difference between the algorithm without multiresolution synthesis and with multiresolution search. The resolution of the exemplar image is 192x192, while all result images' resolution is 256x256. It can be observed that when multiresolution synthesis is disabled, the algorithm cannot capture the large-scale pattern of flowers, so many flowers are broken, except for those flowers in the bottom part, which is nearly completely copied from the exemplar image thanks to coherence search.
Common parameters:
