Thomson Broadcast Systems

Thomson Broadcast

Alain DeMay

Michel Le Lan

Philippe Le Queau

Isabelle Portron

A device and method that overlays, onto a new colored background a subject clipped from a source video image having a subject moving against a first colored background. A clipping key KD is calculated which makes it possible to separate the color space representing the image into three regions, a first region defining a volume representing the first colored background, a second region defining a volume representing the subject, and a third region representing a region of transition between the first colored background and the subject. A video image VD representing the subject moving against the new colored background formed according to the formula:

Device and method for processing a signal with a subject moving against

The invention relates to a method for determining a key KD for clipping a subject moving against a colored background, the said key making it possible to separate the color space into three regions, a first region defining a volume representing the colored background, a second region defining a volume representing the subject and a third region defining a transition region between the colored background and the subject, where the device and method defines the volume representing the colored background in the form of a cone of aperture angle .alpha. whose axis of symmetry (W) passes through the achromic and zero-luminance point of the color space and a point representing the color of the colored background. The invention also relates to any type of electronic apparatus implementing the abovementioned device and method, such as video mixers or autonomous devices for clipping and overlaying video images.

Device and method for determining a key for clipping a subject moving

The disclosure relates to a synchronization device that includes two parallel memory areas, a unit for determination of write states that depends on the phase deviation between the input video signal and the synchronization signal, a write management unit that determines, when it receives a write image pulse, the memory (or memories) to be used for the next write depending on the write state and the memory that is currently being read. The two memories are read sequentially and alternately, whereas the memory(ies) used for each write is variable and determined automatically. The invention enables video signals to be synchronized with respect to a synchronization signal with a frequency deviation tolerance of up to 33%.

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Sartrouville, France

Alain DeMay