Abstract:
A method and an apparatus for encoding and decoding an image based on an exponential-Golomb code by using an optimal threshold are provided to determine thresholds for an exponential-Golomb binarization, consequently improving a gain compared with an image encoding result through a conventional encoding method in a high bit rate environment. A circular coding unit(310) receives an input image, and performs an entropy encoding operation for the input image through an exponential-Golomb binarization which uses plural thresholds about the absolute value of an inputted and quantized DCT coefficient. In addition, the circular coding unit outputs a bit stream generated for each threshold to a bit rate measurement unit(320). The bit rate measurement unit measures the bit rate of the generated bit stream by performing an entropy encoding operation based on each threshold, and then outputs the measured bit rate to an optical threshold determining unit(330). The optical threshold determining unit compares the bit rate for each threshold to determine an optimal threshold, and then outputs the determined the optimal threshold to a bit stream output unit(340).
Abstract:
A quantization coefficient control method and an apparatus thereof for improving the compression efficiency by regulating the quantization coefficient are provided to control quantization coefficient by using non uniform statistical distribution after converting video data in frequency domain. An image transfer data stream is input to an extracting unit(110) from a coding terminal. The statistical property value and the quantized coefficient are extracted. A coefficient control value decision unit(120) inputs coefficient and pixel location much statistical property from an extracting unit. The coefficient control value is especially determined by a block by using coefficients depending on the statistical property. A coefficient control part(130) inputs the coefficient control value from the coefficient control value decision unit.
Abstract:
An intra prediction encoding and decoding method and an apparatus using a differential equation are provided to intra-predict a current block using a differential equation suited to characteristics of the current block to improve prediction accuracy and a video encoding compression rate. An image encoding apparatus(300) includes a threshold determination unit(310), a prediction unit(320), and an encoding unit(330). The threshold determination unit determines a threshold of a differential equation to be used to predict a current block based on pixel values of previously encoded pixels adjacent to the current block. The prediction unit predicts the current block using the differential equation and the determined threshold. The encoding unit encodes the current block based on the prediction result.
Abstract:
영상 복호화 방법이 개시된다. 영상 복호화 방법은 수신된 비트스트림으로부터 파싱된 부호화 단위의 분할 여부를 나타내는 정보를 이용하여, 계층 구조의 부호화 단위들을 결정하고, 결정된 계층 구조의 부호화 단위들 중 현재 부호화 단위의 주변 픽셀들을 이용하여 상기 현재 부호화 단위의 제 1 예측값을 획득하며, 상기 현재 부호화 단위의 상측 경계 및 좌측 경계에 인접한 각 픽셀에 대하여 상기 각 픽셀과 인접한 적어도 하나의 주변 픽셀을 이용하여 상기 상측 및 좌측 경계에 인접한 각 픽셀의 제 2 예측값을 획득하고, 상기 제 1 예측값과 상기 제 2 예측값을 이용하여 상기 현재 부호화 단위의 최종 예측값을 획득한다.
Abstract:
PURPOSE: An image coding method, image encoding method, and apparatus thereof are provided to increase the efficiency of image compression through the process of predicted image data. CONSTITUTION: A first predictive encoding unit is generated by a current encoding unit(2110). A second predictive encoding unit is generated by changing a pixel value of each pixel that consists of a first predictive encoding unit. The difference between a current encoding unit and a second predictive encoding unit is encoded.