Abstract: The present invention improves confidentiality of video without incurring increased processing load. Coefficient scanner 123 scans the orthogonal transform coefficients of the base layer in scanning orders specified by scanning order determiner 150. Coefficient scanner 133 scans the orthogonal transform coefficients of the enhancement layer in scanning orders specified by scanning order determiner 150. When scanning is implemented in a privacy mode, scanning order determiner 150 determines the privacy mode scanning orders of the base layer and the enhancement layer individually and generates scan lists that indicate the scanning orders of the base layer and the enhancement layer respectively. Scan list transmitter 180 the scan lists of the base layer and the enhancement layer, generated in scanning order determiner 150, to specific users alone.

Abstract: A video coding method enabling implementation of resolution scalability while improving the coding efficiency. In the method, a band dividing section 104 performs band division on a high-resolution original image to generate a middle-resolution image, horizontal component, vertical component and diagonal component. The horizontal component is subjected to the DCT processing in horizontal layer DCT section 124, and then subjected to the bit-plane VLC processing in horizontal layer bit-plane VLC section 126. The vertical component is subjected to the DCT processing in vertical layer DCT section 130, and then subjected to the bit-plane VLC processing in vertical layer bit-plane VLC section 132. The diagonal component is subjected to the DCT processing in diagonal layer DCT section 136, and then subjected to the bit-plane VLC processing in diagonal layer bit-plane VLC section 138. In scanning, a scanning order is determined in consideration of bias in the distribution of DCT coefficients for each band component.