Patent ID: 6275269
Filing Date: 2001-08-14
Classification: H04N

Abstract:
A method for calibrating an analog video chromakey mixer, said mixer including a chromakey detector, an adjustable pixel clock, a programmable delay, and an alignment detector in communication with an analog multiplexer and said adjustable pixel clock, said analog multiplexer in communication with said chromakey detector and said programmable delay, said method including steps of:selecting a mpeg video signal that defines a black window;selecting a VGA signal that defines a white window under said black window;adjusting a first chromakey value for said chromakey detector until a first transition is detected by said alignment detector;adjusting a second chromakey value for said chromakey detector until a second transition is detected by said alignment detector;adjusting a difference between the first chromakey value and the second chromakey value to accommodate measurement error.