Video signal processing with two stage motion compensation

1. A method for constructing an output video field from at least four input fields comprising two inner fields and two outer fields, wherein pixel information from the outer fields is temporally shifted to the output field position, the method comprising the steps of:

temporally shifting information from a first one of the outer fields to an adjacent inner field using a first motion vector between the first one of the outer fields and the adjacent inner field; and

temporally shifting information from the inner field to the output field using a second motion vector derived from a motion vector pointing from said adjacent inner field to the other one of the inner fields.

2. A method according to claim 1 , wherein for one of the outer fields that is closest to the output field position, the first motion vector is that pointing backward from the adjacent inner field.

3. A method for constructing an output video field from at least four input fields comprising two inner fields and two outer fields, wherein pixel information from the outer fields is temporally shifted to the output field position, the method comprising the steps of:

temporally shifting information from a first one of the outer fields to an adjacent inner field using a first motion vector between the first one of the outer fields and the adjacent inner field; and

temporally shifting information from the inner field to the output field using a second motion vector derived from a motion vector pointing from said adjacent inner field to the other one of the inner fields, wherein only high frequency information is taken from the outer fields.

4. A method according to claim 3 , wherein said high frequency information is vertical information.

5. The method according to claim 4 , wherein the high frequency information is taken from the outer input fields before being temporally shifted.

6. A method according to claim 3 , wherein the high frequency information is taken from the outer fields before being temporally shifted.

7. A motion compensation device for constructing an output video field from at least four input fields comprising two inner fields and two outer fields, comprising:

a store; and

means for temporally shifting pixel information, and being adapted to temporally shift pixel information from an outer input field to the output field position in two stages, the first stage using a first motion vector between the outer field and the adjacent inner field and the second stage using a second motion vector being derived from a motion vector pointing from said inner field to the other inner field.

8. A method for constructing an output video field from at least four input fields comprising two inner fields and two outer fields, wherein pixel information from the outer fields is temporally shifted to the output field position, the method comprising the steps of:

temporally shifting information from a first one of the outer fields to an adjacent inner field using a first motion vector between the first one of the outer fields and the adjacent inner field; and

temporally shifting information from the inner field to the output field using a second motion vector derived from a motion vector pointing from said adjacent inner field to the other one of the inner fields, wherein for one of the outer fields that is closest to the output field position, the first motion vector is that pointing backward from the adjacent inner and wherein only high frequency information is taken from the outer input fields.

9. The method according to claim 8 , wherein said high frequency information is vertical information.

10. The method according to claim 9 , wherein the high frequency information is taken from the outer input fields before being temporally shifted.

11. The method of claim 8 , wherein the high frequency information is taken from the outer input fields before being temporally shifted.