Patent ID: 8509548
Filing Date: 2013-08-13
Classification: H04N

Abstract:
1. An image decoding apparatus which reproduces and outputs an image from encoded image data encoded by an encoding method configured to designate whether to perform distortion suppression processing of suppressing block distortion before each of two times of frequency conversion, the apparatus comprising: a setting unit which sets a variable magnification ratio; an analysis unit which analyzes a header of decoding target encoded image data and extracts encoding parameter information including at least an execution count of the distortion suppression processing; a decoding unit which decodes the encoded image data up to data immediately before second frequency conversion at the time of encoding; a determining unit which determines, based on the variable magnification ratio set by said setting unit and the encoding parameter information obtained by said analysis unit, which one of two inverse frequency conversion processes corresponding to the two times of frequency conversion executed when the encoded image data is generated and 0 to 2 times of inverse distortion suppression processing corresponding to the distortion suppression processing executed 0 to 2 times when the encoded image data is generated is configured to be omitted; a restoration unit which restores an image on which an output is based, by executing processing configured not to be omitted, based on a determination result obtained by said determining unit; and a re-sizing unit which re-sizes the image restored by said restoration unit in accordance with the variable magnification ratio set by said setting unit and outputs the image.