Intra prediction method and apparatus, and image encoding/decoding method and apparatus using same
The present disclosure relates to an intra prediction method and apparatus and an image encoding/decoding method and apparatus using the same. The disclosure provides the intra prediction apparatus that predicts the pixel values of respective pixels in a current block by weight-averaging the pixel values of one or more adjacent pixels in neighboring blocks to the current block according to the distances between each pixel in the current block and the adjacent pixel(s). According to the disclosure, the current block to be encoded can be predicted more accurately so that the encoding efficiency is improved by reducing the difference between the original block and the predicted block, and thereby video compression efficiency can be improved.
1. An intra prediction apparatus for predicting a current pixel in a current block from neighboring blocks, the apparatus comprising:
a weighted pixel calculator configured to calculate a plurality of weighted pixel values of adjacent pixels selected in the neighboring blocks by applying weights to the adjacent pixels, wherein the weights are decided variably based on a position of the current pixel in the current block; and
a pixel predictor configured to derive an intra-predicted pixel value of the current pixel by dividing a sum of the weighted pixel values of the adjacent pixels by a sum of the weights,
wherein the weighted pixel values comprise a first weighted pixel value and a second weighted pixel value, the first weighted pixel value is calculated by applying a first weight of the weights to a first adjacent pixel in an upper neighboring block, and the second weighted pixel value is calculated by applying a second weight of the weights to a second adjacent pixel in a left neighboring block,
wherein the first adjacent pixel in the upper neighboring block is selected to be vertically at the same position with the current pixel, the second adjacent pixel in the left neighboring block is selected to be horizontally at the same position with the current pixel.
2. The intra prediction apparatus of claim 1 , wherein the weighted pixel values further comprise a third weighted pixel value calculated by applying a third weight of the weights to a third adjacent pixel in one of the neighboring blocks.
3. The intra prediction apparatus of claim 1 , wherein the first weight is decided by the distance between the current pixel and the first adjacent pixel in the upper neighboring block, and the second weight is decided by the distance between the current pixel and the second adjacent pixel in the left neighboring block.
4. The intra prediction apparatus of claim 1 , wherein the weights are decided by the distances between the current pixel and the adjacent pixels in the neighboring blocks.