Extracting coarse boundary features for video processing

We present a method to extract coarse boundary features from discrete cosine transform (DCT) compressed blocks. Video sequences usually contain enormous data for video processing. Decompressing data and then processing uncompressed data is computational intensive. Moreover, this may yield erroneous results due to processing unnecessary data. Our goal is to extract coarse boundary features without decompressing original data, and then to eliminate insignificant blocks for decompressing. The extracted features provide information about the smoothness, the boundary visibility, and the boundary structure of a block. We give an application of using coarse features for video object segmentation.