| 摘要 |
A modified Laplacian-pyramid method and system filters ( 340 - 360, 440 - 460 ) the Gaussian image at each level ( 31 - 33, 41 - 43 ) of the pyramid, and uses the filtered Gaussian image ( 341 - 361, 441 - 461 ) to produce the Laplacian-pyramid images ( 349 - 369, 449 - 469 ). The filtering of the Gaussian image is adaptive, and based at least in part on the characteristics of the Gaussian image at each stage. In one example embodiment, two filters (F 1, F 2 ) are used at each stage, and the Laplacian image ( 349 - 369 ) is based on a filtered version of the Gaussian image and an upsampled filtered version of a downsampling ( 346 - 366 ) of the Gaussian image. In another example, filter is used, and the Laplacian image ( 449 - 469 ) is based on the filtered version ( 441 - 461 ) of the Gaussian image and an upsampled downsampling ( 446 - 466 ) of the filtered version of the Gaussian image. By forming the Laplacian images ( 349 - 369, 449 - 469 ) from the filtered Gaussian images ( 341 - 361, 441 - 461 ), the aliasing conventionally produced by filtering the Laplacian images is substantially reduced. |
