POWER-EFFICIENT SHAPE ADAPTIVE DISCRETE COSINE TRANSFORMATION

摘要

An apparatus (216) is provided for encoding image data, which comprises processing means (220) for processing a shape-adaptive discrete cosine transformation, an input buffer (217), a transpose memory (218) and an output buffer (219). The apparatus (216) receives image data as picture screen elements (pixels), each of which is defined with respective luminance, chrominance and alpha values (301). The input buffer (217) is configured to store pixels vertically (401) as the image data (402) is received. The processing means (220) is configured to process a plurality of first coefficients from the vertically-stored pixels and a plurality of second coefficients from the first coefficients. The transpose memory (218) is configured to store the plurality of first coefficient horizontally (403) as they are output. The output buffer (219) is configured to output (406) the second coefficients (407) as they become available from the processing means (405), whereby the second coefficients are output with minimal latency.