| 摘要 |
PURPOSE: A moving image coding method is provided to extract hidden data when necessary after hiding the data in a multimedia moving image using a video CODEC, without increasing an amount of encoded data and a change of picture quality, consequently original data is unnecessary when extracting the hidden data. CONSTITUTION: A system extracts a motion vector through a motion compensation and a motion prediction with regards to an inputted image, performs a DCT process for a difference image, and sets initial quantization parameters. The system carries out a data hiding process in the quantization parameters, and changes the parameters to recognize whether the data is hidden. The system performs a quantization by using the changed parameters. The system changes a level value of each block in DCT block units, and hides the data. |
