Patent ID: 7944973
Filing Date: 2011-05-17
Classification: H04N

Abstract:
1. A video encoding method for subjecting a to-be-encoded of an input image to motion compensated prediction encoding with reference to a first reference image and a second reference image, the method comprising: calculating (A) a first distance between the first reference image and the input image and (B) a second distance between the first reference image and the second reference image; calculating a first weighting factor for the first reference image and a second weighting factor for the second reference image based on a ratio of the first distance to the second distance; generating a prediction image by calculating a linear sum of the first reference image and the second reference image according to the first weighting factor and the second weighting factor; generating a prediction error representing an error of the prediction image with respect to the to-be-encoded block; and encoding quantized orthogonal transform coefficient information obtained by subjecting the prediction error to orthogonal transform and quantization, wherein the calculating the first weighting factor sets values of both of the first weighting factor and the second weighting factor to a value for an average prediction if: (1) the second weighting factor is larger than an upper limit, or (2) the second weighting factor is smaller than a lower limit, or (3) at least one of the first image and the second image is a long term reference image.