Motion compensation predicting encoding method and apparatus

DETAILED DESCRIPTION The foregoing objects and other objects and advantages will be realized by the present invention in which a motion compensation predicting coding apparatus encodes pixel data of an image signal.
The image signal includes pixel data organized into a even field and odd field for a portion of an image.
The apparatus includes a motion detector for comparing the pixel data in the image signal with pixel data of a previous image signal.
The motion detector generates a motion vector that is indicative of the displacement differences between the image signal and the previous image signal.
The motion compensation predicting coding apparatus also includes a subtracter for generating a prediction compensation error signal by subtracting the pixel data in the previous image signal from the pixel data of the current image signal.
The resulting prediction compensation error signal is passed through an adaptive blocking mechanism that organizes the data of the prediction compensation error signal into blocks in one of several fashions.
The blocking strategy is chosen as dictated by the motion vector.
The blocking mechanism generates a blocked output that is fed to a coder and encoded.
The motion compensation predicting coding apparatus may alternatively include a field composer for composing the odd field pixel data in the incoming image signal with even field pixel data in the incoming image signal to produce a composed image signal.
This composed image signal has pixel data for both the even and odd fields.
This composed image signal is used by the motion detector in determining the motion vectors.
Thus, in this alternative embodiment, the motion detection is not carried out strictly on single field blocks but rather is carried out on field composed blocks.
The coder for encoding output may include several components.
First, the coder may include a transformation means for performing an orthogonal transformation on the prediction error signal to produce a coefficient matrix.
Second, the coder may include a quantizer for quantizing the coefficients from the coefficient matrix and a scanning controller for controlling what order the coefficients are scanned from the coefficient matrix and passed to the quantizer