Crystal Vision
Introduction
•
Compatible
with Crystal Vision standard frames available in 2U, 1U and desk
top box.
•
Passes all ancillary data.
Block Diagram
Safire 3 simplified block diagram
Block Diagram Description
The Foreground (FG), Background (BG) and External Key video inputs are firstly
frame synchronised, delayed and timed to an external analogue Black and Burst or
tri-level syncs reference, or to one of the other inputs.
The FG signal is then passed to the FG suppression block where, in Suppress
Foreground mode, all colours in the FG acceptance window are de-saturated to
shades of grey and any colour exactly the same as the FG hue colour will be
suppressed to black. Luminance is subtracted from the suppressed signal to ensure
that all the coloured backdrop area is black. In Multiply Foreground mode the
suppression block is bypassed.
A key is derived from the chroma key processing block which is maximum for FG
colours exactly the same as the Chroma Key Colour hue. All other colours within the
Chroma Key Colour acceptance window will produce varying amounts of key from
maximum in the centre to zero at the edges. The clipped chroma key is combined
with other keys and masks to produce a single key which is used to cut a hole in the
Background video – and in Multiply Foreground mode only, the inverse key cuts a
hole in the FG signal as well.
Safire 3 User Manual R1.3
6
24 March 2017