Apparatus and method for encoding and decoding moving picture using adaptive scanning
Provided is an apparatus and method for encoding/decoding a moving picture based on adaptive scanning. The moving picture apparatus and method can increase a compression rate based on adaptive scanning by performing intra prediction onto blocks of a predetermined size, and scanning coefficients acquired from Discrete Cosine Transform (DCT) of a residue signal and quantization differently according to the intra prediction mode. The moving picture encoding apparatus includes: a mode selector for selecting and outputting a prediction mode; a predictor for predicting pixel values of pixels to be encoded of an input video based on the prediction mode to thereby output a residue signal block; a transform/quantization unit for performing DCT onto the residue signal block and quantizing the transformed residue signal block; and an encoder for adaptively scanning and encoding the quantized residue signal block based on the prediction mode.
1. A non-transitory computer-readable storage medium storing a program for controlling a computer to perform a method of decoding motion pictures based on adaptive scanning, the method comprising:
performing entropy decoding of an encoded bitstream to obtain entropy-decoded signals;
determining a scanning method for the entropy-decoded signals;
recovering a picture from the entropy-decoded signals according to the scanning method; and
outputting the recovered picture;
wherein the scanning method is an adaptive scanning method according to an intra prediction mode for the entropy-decoded signals and comprises:
scanning entropy-decoded signals of a first row with priority so that all of the entropy-decoded signals of the first row are scanned prior to scanning entropy-decoded signals of any other row in response to the intra prediction mode being a vertical mode; and
scanning entropy-decoded signals of a first column with priority so that all of the entropy-decoded signals of the first column are scanned prior to scanning entropy-decoded signals of any other column in response to the intra prediction mode being a horizontal mode.
2. The storage medium of claim 1 , wherein the method further comprises inverse-transforming and dequantizing the entropy-decoded signals after determining the scanning method for the entropy-decoded signals.
3. The storage medium of claim 1 , wherein the recovering comprises first scanning entropy-decoded signals of blocks in a first row of blocks.
4. The storage medium of claim 1 , wherein the entropy-decoded signal is a transformed and quantized residue signal that represents a difference between a pixel value and a predicted pixel value.
5. A non-transitory computer-readable storage medium storing a program for controlling a computer to perform a method of decoding motion pictures based on adaptive scanning, the method comprising:
performing entropy decoding of an encoded bitstream to obtain entropy-decoded signals;
determining a scanning method for the entropy-decoded signals;
recovering a picture from the entropy-decoded signals according to the scanning method; and
outputting the recovered picture;
wherein the scanning method is an adaptive scanning method according to an intra prediction mode for the entropy-decoded signals and comprises:
scanning entropy-decoded signals of a first row with priority so that all of the entropy-decoded signals of the first row are scanned prior to scanning entropy-decoded signals of any other row in response to the intra prediction mode being a vertical mode, and then scanning entropy-decoded signals of a second row so that only some and less than all of the entropy-decoded signals of the second row are scanned prior to scanning at least one entropy-decoded signal of a third row; and
scanning entropy-decoded signals of a first column with priority so that all of the entropy-decoded signals of the first column are scanned prior to scanning entropy-decoded signals of any other column in response to the intra prediction mode being a horizontal mode, and then scanning entropy-decoded signals of a second column so that only some and less than all of the entropy-decoded signals of the second column are scanned prior to scanning at least one entropy-decoded signal of a third column.