IMAGE PROCESSING DEVICE AND IMAGE PROCESSING METHOD

摘要

It is possible to suppress image quality degradation caused by encoding. The present invention multiplies a decoding rescaling factor (RFr) which may be used during decoding only by a conversion matrix (D) as a scale fluctuation so as to calculate rescaling factors (RF) as division factors and calculate a sum (S?) of evaluation values (?) based on a remainder (r) when an elements in the DCT coefficient is divided by the rescaling factors (RF), for each of detection unit. Furthermore, the present invention compares relationships between the rescaling factors (RF) and the sum (S?) of evaluation values (?). The rescaling factor (RF) at which the sum (S?) of evaluation values (?) is minimum is used to detect a quantization factor used upon the previous encoding of the input image data.