Automatic black box testing of television systems on the final production line

The current verification methodologies on the final production line in digital television industry require a significant amount of manual work in connecting and disconnecting the television set to and from signal sources and verifying the correctness and quality of image shown on the TV screen. This manual work slows down the production and increases the cost of a final production line. This paper proposes an automatic system which will perform all required verification steps on the final production line such that manual work will be minimized, speed of the production will significantly increase and the cost of the final production line will decrease. The proposed final production line uses the camera to capture the image shown on the TV screen which improves the earlier solution with the grabber to allow verification of the image quality as seen by the user. The proposed system consists of: (1) TV set being verified, (2) camera to capture the content on the TV screen, (3) signal generator, (4) test monitoring system and (5) PC which runs the algorithm for extraction of the TV screen content and comparison with the referent content. The proposed algorithm uses the block-based normalized cross-correlation to compare captured and referent content. The proposed testing methodology divides the verification on the final production line in three steps: (1) setup phase, during which the TV set is brought and connected to the signal sources and test monitoring system, (2) execution phase which captures the content on the TV screen and runs the PC algorithm and (3) test report phase which reports the pass/fail result of the test in the test monitoring system. The experimental results of the block-based comparison method show a better sensitivity to small differences than the non-block-based method. The time required for verification step increased by a factor of 5 when using the automatic approach on the final production line instead of a manual one.