Movement detector for television signals
AssigneeBritish Broadcasting Corporation
InventorsRichard Storey, Alan Roberts
Life of this patent
Estimating the term…
Abstract
A movement detector for television signals measures the difference between maximum and minimum values of the movement components of a picture difference signal over a chosen interval. A television signal at an input (12) is delayed in a picture delay (2), and the delayed and undelayed signals subtracted in a subtractor (1) to form a picture difference signal. This is rectified in rectifier (3) and smoothed in a filter (4). A maximum detector (6) and a minimum detector (7) are coupled to the filter output and are re-set at prescribed intervals. A subtractor (8) determines the difference between the output of detectors (6) and (7) and this is compared with a reference value in a comparator (9), the output of which is sampled and stored in a store (10).
Claims7
A movement detector for detecting movement in selected picture areas of a video signal, comprising:
- an input for receiving an input video signal;
- difference signal generating means connected to the input for generating a signal representative of the difference between the input signal on two different field scans;
- extreme value determining means for determining for a selected area or areas of the picture maximum and minimum values of the difference signal;
- and
- comparing means for comparing the value of said maximum value minus said minimum value with a reference value.
Dependencies are inferred from the claim text.