Innovision Corporation

British Broadcasting Corporation

Leitch Europe Limited

Timothy John Borer

Andrew David Raine Cotton

Graham A Thomas

Gary Bryan Wordsworth

David Christopher Clarkson

Described are concepts, systems and techniques related to processing an input video signal intended for a first display to produce an output signal appropriate for a second display. The concepts, systems and techniques include converting using one or more transfer functions arranged to provide relative scene light values and remove or apply rendering intent of the input or output video signal, wherein the removing or applying rendering intent alters luminance.

Method and apparatus for conversion of HDR signals

A technique is disclosed for estimating the measurement error in motion vectors used for example in a motion compensated video signal process. For each motion vector corresponding to a region of an image a plurality of temporal and spatial image gradients are calculated corresponding to that region. From the constraint equations of the image gradients a plurality of error values can be calculated for each motion vector and a parameter generated describing the size of the distribution of motion vector measurement errors. Subsequent processing of the video signals using the motion vectors can then be adapted, for example by graceful fallback in motion compensated interpolation, depending on the accuracy of each motion vector. The 'confidence' in the accuracy of each motion vector can be described by a parameter calculated in relation to the size of the error distribution and the motion vector speed.

Motion vector field error estimation

A technique for generating motion vectors for applications is requiring field of frame rate interpolation and especially in standards conversion. The image gradients on the same standard as the input video or film signal and then vertical/temporal interpolators are used to convert to the output standard before determining the motion vectors. This allows motion vectors to be easily calculated on the output standard.

Gradient based motion estimation

This invention provides a way of performing improved motion compensated interpolation of moving images, such as television, using motion vectors of variable reliability. By taking into account the reliability of the motion vectors, produced by a separate motion estimation device, a subjectively pleasing interpolation can be produced. This is in contrast to simple motion compensated interpolation, taking no account of motion vector reliability, which is often degraded by objectionable switching artifacts due to unreliable motion vectors. The invention can be used, for example, to improve the performance of motion compensated standards converters used for converting between television standards with different picture rates. The invention allows a gradual transition between motion compensated and non-motion compensated interpolation depending on the reliability of the motion vector used. This is achieved by modifying the temporal interpolation timing, using a look up table, controlled by a vector reliability signal produced by the motion estimator. Effectively this adapts the motion trajectory of the interpolated output pictures.

Motion compensated interpolation

A technique for generating motion vectors in video and film signal processing uses constraint equation based motion estimation. Simplifications of the processing and hardware are made possible by generating motion vectors based on the normalized constraint equation. The temporal and spatial image gradients are calculated using temporal and spatial differentiators ( ). An angle (&thgr;) corresponding to the orientation of the spatial image gradient vector and the motion speed (vn) in the direction of the vector are calculated using apparatus including a rectangular to polar coordinate converter ( ). &thgr; and vn are the parameters of the normalized constraint equation.

A high speed analog-to-digital converter utilizes a fine resolution ADC to digitize the low band component of an analog video signal to produce a fine resolution signal and a coarse resolution ADC to digitize the full spectrum of the analog signal and produce a coarse resolution signal. The coarse resolution signal is subtracted from the fine resolution signal to generate a summed signal containing a quantization error, which is filtered through a low pass digital filter to filter out the high band component and pass the quantization error. The filter output is summed with the coarse resolution signal to restore the fine resolution of the low band, producing a digital output signal that has a resolution suitable for high definition applications.

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Surrey, United Kingdom

Timothy John Borer