Abstract: Disclosed herein are a video decoding method and apparatus and a video encoding method and apparatus. In image encoding, encoding using multiple quantization parameters is performed on a transform coefficient. Two quantized coefficients are generated through encoding that uses two quantization parameters. Based on the two quantized coefficients, a quantized coefficient difference is generated. Information about the quantized coefficient difference is transmitted from an encoding apparatus to a decoding apparatus through binary encoding. The information about the quantized coefficient difference may be selectively transmitted. By means of the information about the quantized coefficient difference, a high-quality video may be provided.

Abstract: Disclosed herein is a context-adaptive entropy model for end-to-end optimized image compression. The entropy model exploits two types of contexts. The two types of contexts are a bit-consuming context and a bit-free context, respectively, and these contexts are classified depending on the corresponding context requires the allocation of additional bits. Based on these contexts, the entropy model may more accurately estimate the distribution of each latent representation using a more generalized form of entropy models, thus improving compression performance.

Abstract: An apparatus and method perform rate-distortion optimization based on cost. The encoding apparatus selects an encoding mode to be used to encode a target block from among multiple modes and performs computation for rate-distortion optimization in the encoding mode. The encoding apparatus calculates a cost of at least one of the multiple modes in relation to the encoding of the target block, and selects the encoding mode from among the multiple modes, based on the cost.

Abstract: Disclosed herein are an inter-prediction method and apparatus using a reference frame generated based on deep learning. In the inter-prediction method and apparatus, a reference frame is selected, and a virtual reference frame is generated based on the selected reference frame. A reference picture list is configured to include the generated virtual reference frame, and inter prediction for a target block is performed based on the virtual reference frame. The virtual reference frame may be generated based on a deep-learning network architecture, and may be generated based on video interpolation and/or video extrapolation that use the selected reference frame.

Abstract: Disclosed herein are a video decoding method and apparatus and a video encoding method and apparatus. A virtual frame is generated by a video generation network including a generation encoder and a generation decoder. The virtual frame is used as a reference frame in inter prediction for a target. Further, a video generation network for inter prediction may be selected from among multiple video generation networks, and inter prediction that uses the selected video generation network may be performed.

Abstract: Disclosed herein are a video decoding method and apparatus and a video encoding method and apparatus. In quantization and dequantization, multiple quantization methods and multiple dequantization methods may be used. The multiple quantization methods include a variable-rate step quantization method and a fixed-rate step quantization method. The variable-rate step quantization method may be a quantization method in which an increment in a quantization step depending on an increase in a value of a quantization parameter by 1 is not fixed. The fixed-rate step quantization method may be a quantization method in which the increment in the quantization step depending on the increase of the value of the quantization parameter by 1 is fixed.

Abstract: Disclosed herein are a method and apparatus for video encoding and decoding using picture partition information. Each of the pictures in a video is partitioned into tiles or slices based on picture partition information. Each picture is partitioned using one of at least two different methods based on the picture partition information. The picture partition information may indicate two or more picture partitioning methods. The picture partitioning methods may be changed either periodically or according to a specific rule. The picture partition information may describe such a periodic change or the specified rule.

Abstract: Disclosed herein are an apparatus and method for performing rate-distortion optimization based on cost. The encoding apparatus selects an encoding mode to be used to encode a target block from among multiple modes and performs computation for rate-distortion optimization in the encoding mode. The encoding apparatus calculates a cost of at least one of the multiple modes in relation to the encoding of the target block, and selects the encoding mode from among the multiple modes, based on the cost.

Abstract: An image encoding method and apparatus and an image decoding method and apparatus are provided. The image encoding method and image decoding method may enhance performance of the image encoding apparatus and performance of the image decoding apparatus by adaptively applying a tile-based parallel encoding scheme, a frame-based parallel encoding scheme, and an instantaneous decoding refresh (IDR) period-based parallel encoding scheme.

Abstract: Methods for Joint Photographic Experts Group (JPEG) 2000 encoding and decoding based on a graphic processing unit (GPU) are provided. The method for JPEG2000 encoding based on a GPU includes receiving input image data from a central processing unit (CPU), encoding the image data, and transferring the encoded image data to the CPU.

Abstract: Provided are an apparatus and method for compression-encoding a moving picture at high speed while minimizing image quality deterioration. In H.264 moving picture encoding, the apparatus and method perform rate-distortion optimization (RDO) indispensable for high-definition encoding by feedback prediction, and minimize the amount of discrete cosine transform (DCT)-inverse DCT (IDCT) calculation performed for RDO many times, thereby performing H.264 encoding at high speed.

Abstract: Provided are a coded block pattern (CBP) estimating method which is performed using an average value and a dispersion value between blocks of CBPs in a moving picture encoder for IP-TVs (Internet Protocol-Televisions), and a block mode decision method, which can determine all block modes with only the first 16×16 block. Accordingly, since an additional operation for mode determination is not necessary, an amount of calculation and thus a calculation time can be remarkably reduced.

Abstract: A fast block mode determining method for motion estimation, and an apparatus thereof. A cost of motion estimation for an input image frame is predicted by Kalman filtering, and one block mode is selected from a plurality of block modes. A cost for the motion estimation of the input image frame is calculated. The predicted cost and the calculated cost are compared with each other, and the block mode for performing the motion estimation is determined. In an H.264 moving picture encoding device, the operation load is reduced and time wasted for calculation is shortened, because it is not necessary to perform the motion estimation for all the block modes.

Abstract: Provided are a method and apparatus for determining a block mode using bit-generation probability estimation in motion picture coding. In H.264 video coding for Internet protocol (IP)-television (TV), the method and apparatus first determine whether or not a current block mode is a skip mode or a direct-prediction mode using bit-generation probability estimation, thereby reducing the amount of computation. By minimizing the amount of computation for determining a block mode, it is possible to increase an encoding rate and also minimize deterioration in image quality.

Abstract: Provided are an apparatus and method for compression-encoding a moving picture at high speed while minimizing image quality deterioration. In H.264 moving picture encoding, the apparatus and method perform rate-distortion optimization (RDO) indispensable for high-definition encoding by feedback prediction, and minimize the amount of discrete cosine transform (DCT)-inverse DCT (IDCT) calculation performed for RDO many times, thereby performing H.264 encoding at high speed.

Abstract: A fast block mode determining method for motion estimation, and an apparatus thereof. A cost of motion estimation for an input image frame is predicted by Kalman filtering, and one block mode is selected from a plurality of block modes. A cost for the motion estimation of the input image frame is calculated. The predicted cost and the calculated cost are compared with each other, and the block mode for performing the motion estimation is determined. In an H.264 moving picture encoding device, the operation load is reduced and time wasted for calculation is shortened, because it is not necessary to perform the motion estimation for all the block modes.

Abstract: The invention relates to a fixed point multiplying apparatus and method using an encoded multiplicand. The multiplicand is encoded into an independent binary system instead of a conventional binary system and each bit value of the encoded multiplicand is used as a control signal about an inputted multiplier in order to effectively execute a fixed point multiplication used in a transform algorithm such as the DCT (Discrete Cosine Transformation) in use for a multimedia codec. The multiplication is executed at a high speed with a simple structure and a small gate number.

Abstract: The invention relates to a fixed point multiplying apparatus and method using an encoded multiplicand. The multiplicand is encoded into an independent binary system instead of a conventional binary system and each bit value of the encoded multiplicand is used as a control signal about an inputted multiplier in order to effectively execute a fixed point multiplication used in a transform algorithm such as the DCT in use for a multimedia codec. The multiplication is executed at a high speed with a simple structure and a small gate number.