| 摘要 |
<p>Provided is a video coding method and a video decoding method capable of increasing the resolution and quality of images while suppressing an amount of data required for increasing the resolution. A video coding apparatus (100) includes: a first orthogonal transformation unit (102) which performs discrete cosine transform on an input picture signal (101); a low-pass filter (116) which performs low-pass filtering on the input picture signal (101); a downsampling unit (108) which downsamples the resolution of a low-frequency image signal (117); a coding unit (110) which compresses and codes a reduced image signal (109); a local decoding unit (112) which decodes a coded bit stream (111); a second orthogonal transformation unit (114) which performs discrete cosine transform on a decoded image signal (113); and a modification information generation unit (104) which generates, based on input image DCT coefficients (103) and decoded image DCT coefficients (115), coefficient modification information (105) used for modifying orthogonal transformation coefficients obtained by performing orthogonal transformation on a decoded video signal obtained from a coded bit stream.</p> |
