| 摘要 |
At least one selected image of a digital video signal is encoded at multiple levels of resolution. For each level of resolution, a correction image is formed by subtracting the value of each pixel in a reference image of that resolution level from the value of each corresponding pixel in the selected image of that resolution level. The correction image is quantized and encoded. A decoder decodes the encoded quantized correction image for each resolution level. The value of each pixel in the decoded correction image having the lowest resolution is added to the value of each corresponding pixel of a reference image having the same resolution to form a result image of the lowest resolution. This result image is expanded to the next higher level of resolution. The value of each pixel in the expanded result image is added to the value of each corresponding pixel in the decoded correction image of the same resolution level to form a result image of that resolution level. This process is continued until each pixel value in the expanded result image, which has been expanded to full resolution, is added to the value of each corresponding pixel in the full resolution decoded correction image to form the final image which is stored in memory for subsequent display. |
