SMOOTHED LOCAL HISTOGRAM FILTERS FOR COMPUTER GRAPHICS

摘要

Local histogram and local histogram based functions can be determined by generating offset kernel images based on domain shifted tonal filter kernels. The offset kernel images are reusable for multiple image locations and/or local neighborhood sizes, shapes, and weights. A neighborhood filter representing the desired local neighborhood size, shape, and frequency domain characteristics is applied to the offset kernel images. Neighborhood filters may include a temporal dimension for evaluating neighborhoods in space and time. Neighborhood filtered offset kernel images' values represent samples of local histogram or local histogram based function corresponding with the domains of their associated domain shifted tonal filter kernels. Tonal filter kernels may be arbitrary functions. Local histogram functions' values may be sampled with a histogram kernel. A tonal filter kernel that is a derivative or integral of another tonal filter kernel may be used to sample a derivative or integral, respectively, of a function.