IMAGE ENCODING APPARATUS, IMAGE DECODING APPARATUS, IMAGE ENCODING METHOD, AND IMAGE DECODING METHOD

摘要

In order to reduce, even more, the amount of data to be generated upon encoding an image having a bit depth greater than that of an encoder, an image encoding apparatus (100A) of the present invention is provided with: a downconverter (102A) for generating a base layer image by implementing downconversion, which is to reduce the bit depth of the subject image by a first-value's worth; a first encoder (111A) for generating a rebuilt image by encoding and decoding the base layer image; a subtracter (103A) for implementing processing to increase the bit depth of the rebuilt image by a second-value's worth, and generating an enhancement layer image for enhancing the image quality of the base layer image on the basis of the image subjected to the aforementioned processing and the rebuilt image; a second encoder (112A) for encoding the enhancement layer image; and an output unit (115) for outputting the encoded base layer image and the encoded enhancement layer image.