Apparatus and method for image coding

摘要

In an electronic still camera, a compression coefficient estimating unit (9) performs preencoding using only an LA component of FBTC compressed data read from an image memory (4), and estimates an optimal compression ratio based on the result of preencoding. Thereafter, JPEG encoder (7) performs JPEG compression on the image data applied from FBTC decoder (5) with the estimated compression coefficient, and transfers the result to a recording apparatus (10). As compared with the prior art in which image data is directly preencoded, the time for preencoding can be significantly reduced and image memory (4) requires smaller capacity.