Showing papers on "Residual frame published in 1969"

Predictive video encoding using measured subject velocity

Abstract: In an encoding system for use with video signals, the velocity of a subject between two frames is estimated and used to predict the location of the subject in a succeeding frame. Differential encoding between this prediction and the actual succeeding frame are used to update the prediction at the receiver. As only the velocity and the updating difference information need be transmitted, this provides a reduction in the communication channel capacity required for video transmission. The scheme may be implemented by comparing the intensities of points in consecutive frames, identifying those points having a significant frame to frame intensity difference as part of the moving subject, determining an estimated velocity of the identified subject, predicting the present frame by translating a portion of the previous frame by the estimated velocity (the translated portion forming the identified subject), and transmitting the updating difference between the actual and predicted present frames along with the predictive velocity information.

Redundancy reduction system for use with a signal having frame intervals

Abstract: A redundancy reduction system is described in which plural amplitude samples of a video signal are taken during each frame interval. The amplitude values for each set of four samples are coupled to the input of a circuit which operates in accordance with a fixed function to produce an indicator word for that set. The indicator words thereby generated for an entire frame interval are stored in a frame memory at positions in the memory corresponding to their respective set positions within the frame interval. In succeeding frames a similarly generated indicator word for a set of samples is compared with its corresponding stored indicator word from the frame memory. Only if a difference exists between the two indicator words is the set of new amplitude samples transmitted to a receiving location.

Frame synchronization arrangement for pcm systems

Abstract: The decoder produces output containing a detectable signal component equal to one-half the frame repetition rate when an out of sync condition is present. A bandpass filter detects the signal component and produces a pulse which is inserted into the bit clock from which the frame clock is derived for operating the decoder. The frame clock is shifted one bit each frame until a sync condition is achieved and the signal component disappears. A feedback circuit inhibiting the filter output is provided to prevent for a given time interval generating a succession of additional pulses after the first extra pulse is inserted into the bit clock.