Abstract: A method and apparatus for analysing the motion of an object in an motion video in which the frame of a video image (suitably converted to graphics format) is displayed on a video display unit and overlaid by a graphics image including a mouse pointer. The mouse is manipulated by the user to capture the pixel coordinates of the desired object in successive frames of the video thereby providing data which represents the variation in position of the object with time.

Abstract: In a communication network for communication between a plurality of nodes over a multi-channel communication medium 6, the network has a number of allocatable channels, . . . for data communication between nodes and a control channel 26 for allocating the allocatable channels to individual nodes. At least one of the channels operates under a token-passing protocol with a limited message packet length whereby selected messages may be sent between nodes with a predetermined maximum delay. The token-passing channel may be the control channel, and the message packets transmitted by the nodes over the control channel may comprise messages for negotiating the allocation of the allocatable channels to the individual nodes. Alternatively, or additionally, message packets comprising data messages unconnected with negotiating the allocation of the allocatable channels may be sent over such a token-passing channel.

Abstract: Multibeam cathode ray tube apparatus incorporates control circuits for maintaining the relative intensity of the beams over a range of settings of the brightness control. As applied to a three beam color tube, at least two, and preferably all three, of the electron guns have each a control circuit located between the control grid (V.sub.gl) and a variable voltage source (V) which constitutes the brightness control of the display. A potentiometer (R.sub.1) allows the voltage (V) to be variably attenuated and a second potentiometer (R.sub.2) acting in conjunction with a current source (I) allows the attenuated voltage to have a variable voltage added thereto. The potentiometers (R.sub.1 and R.sub.2) for each electron gun are adjusted to bring the brightness versus control voltage characteristic for each gun into coincidence. The current source (I) may be constituted by a fixed resistor and a fixed voltage. The invention is also applicable to multibeam monochrome tubes.

Abstract: A line scan circuit for a cathode ray tube display includes a phase detector (3), integrator (4), voltage controlled oscillator (5) and line output stage (6). The integrator, voltage controlled oscillator and line output stage are conventional, but the phase detector is novel. The phase detector compares the phase difference for both the leading and trailing edges of the horizontal synchronization pulses and the line flyback pulses. This forces the line flyback pulses to be centered with respect to the synchronization pulses resulting in improved centering and linearity of the displayed picture.