1. An apparatus, comprising: an encoder encoding at least a portion of an image using de-artifact filtering, said encoder comprising a de-artifacting filter that performs the de-artifact filtering by grouping regions within the portion based on dimensions and characteristics of the region or portion, transforming the grouped regions, adaptively performing the de-artifact filtering on the transformed regions, inverse transforming the de-artifacted regions to create replacement regions, and restoring the replacement regions to positions with the image from which the regions were taken prior to the grouping, wherein multiple estimates of the same pixel are obtained from overlapping regions and, for each pixel, adaptive sparsity-based filtering is used to fuse multiple estimates from redundant representations of the overlapping regions, and wherein a type and a strength of the de-artifact filtering is adaptively selected responsive to characteristics of at least one of quantization noise statistics, coding modes and motion information, local coding conditions, and compression requirements.