Patent ID: 9674521
Date: 2017-06-06
CPC Classifications: H04N

Claim:
1. A method of predicting a chrominance component image by using a luminance component image, the method comprising: down-sampling inner pixels of a luminance prediction unit and adjacent pixels of the luminance prediction unit, the luminance prediction unit having been pre-encoded and pre-restored, considering a size of a luminance prediction unit and a size of a chrominance prediction unit corresponding to each other according to a color format; obtaining parameters indicating a correlation between the luminance prediction unit and a predicted chrominance prediction unit based on the down-sampled adjacent pixels of the luminance prediction unit and restored adjacent pixels of the predicted chrominance prediction unit; and obtaining, from the down-sampled luminance prediction unit by using the obtained parameters, a prediction value of a chrominance prediction unit corresponding to the down-sampled luminance prediction unit, wherein the down-sampling comprises: wherein the first location and first filtering method used for down-sampling with respect to the inner pixels of the luminance prediction unit, the second location and second filtering method used for down-sampling with respect to the adjacent upper pixels of the luminance prediction unit, and the third location and third filtering method used for down-sampling with respect to the adjacent left pixels of the luminance prediction unit are independently selected, wherein, when the size of the luminance prediction unit is 2nS×2nS where nS is a positive integer: