1) Employing the interlaced scanning, current TV system can compress the frequency band of TV signal effectively and facilitate transmission.

2) In another aspect, for a first interlaced scanning video frame in a video sequence, a decoder decodes a bitplane signaled at frame layer for the first interlaced video frame.

3) Interlaced scanning is widely used in the telecast system in the world.

4) Said invention also can inhibit frame-frequency flash during contour scanning in the interlaced scanning system, and can produce image contour intensified effect.

5) Each row from the left to the right of each frame according to the interlaced scanning, from top to bottom odd lines, even two sweeping, used to reduce flicker sensation.

6) The different information is implemented to clear and steadily display by using of time-shared display with line by line scanning and interlaced scanning in a raster picture.