Rank Cintel Limited

Eastman-kodak Company

Cintel International Limited

Terence W Mead

Ronald W Mumford

Lawrence J Bernstein

Peter R Swinson

Richard T Such

A film scanner of the type which uses diffuse illumination and an array sensor such as a line array or area array CCD includes an integrating optical element in the form of an integrating sphere to provide diffuse illumination to film. The diffuse illumination ensures that light is provided to film at a range of angles thereby improving the light level reaching the array sensor from film that has been scattered by defects such as scratches thereby reducing the visibility of such defects. A lens is provided at the exit aperture of the integrating sphere so as to define a particular area of the surface within the integrating sphere from which light that is not scattered by film is derived. The area has a lower reflectivity than the remainder of the integrating sphere thereby increasing the amount of light derived from scratches that reaches the sensor to further reduce the visibility of scratches. An additional light source can also be provided at the area of the integrating sphere so as to increase the visibility of scratches to produce a separate signal by which a main image signal may be corrected.

Optical scatter correction for film scanners

Film unsteadiness in a flying spot film scanner (10) is measured by reference to film image movement based on a measure of the direction of movement acquired by examination by a movement compensator 30 of spatial and temporal differences around a given pixel. A correction signal is generated and applied as a feedback signal to the X and Y circuits of the scan generator (20).

Correction of film instability based on movement of the video image

A film instability compensating system compensates for the effects of film instability in a film gate. The film instability compensation system includes a positional transducer for measuring the position of the film edge relative to a sprocket hole which is maintained in contact with a sprocket tooth by a pressure roller. The positional transducer measures the distance between the film edge and a sprocket hole and then measures deviations from the distance for subsequent sprocket holes to determine a compensation signal. The output of the positional transducer is coupled to a delay unit which delays the signal corresponding to the error at a particular sprocket hole until that sprocket hole reaches the film gate. Signals representative of the cyclic errors caused by the relative lateral displacement of the sprocket holes, are stored in a memory and are applied to a subtractor circuit. In the subtractor circuit, the compensation signal from the output of a pipeline register delay is adjusted to compensate for cyclic errors, and to provide an overall compensation signal which is applied to the horizontal scan shift when the appropriate sprocket hole reaches the film gate.

Method and apparatus for compensating for film registration weave in

To avoid the effect of blemishes in a CRT phosphor of a CRT film scanner a map is produced identifying areas of the phosphor that are blemished. When a line scan traverses a blemish the signal produced by that scan is inhibited and the area of film is rescanned with the film in a different position relative to the scanner.

Method of and apparatus for scanning cinematographic film while avoiding

Compensation for phosphor burn in a CRT scanner is achieved by offsetting the scan by half a line spacing on alternate scans when the film is stationary in the scanner. To avoid unpleasant effects the offset scan output is supressed and the previous frame output frozen in the frame store 24. The previous frame is output again from the frame store in place of the offset scan output. Offset scanning is not performed when a control adjustment is made to avoid a juddering effect on the displayed output.

Cathode ray tube burn compensation

Electronic film editing with system having telecine mode and film

In a flying spot telecine including cathode ray tube scanning circuit for generating flying spot and a photodetector for receiving light transmitted by a film strip being scanned by the telecine, a control circuit is provided for causing the CRT scanning circuit to scan an area (18) corresponding to the position of one or more perforations (16) in the film strip (10) being scanned. The output from the photodetector during a scan of the area (18) provides a correction signal for adjusting the video signal level. Preferably, the scan of the area (18) is performed during line blanking or frame blanking periods.

Method and apparatus for correcting drift in the level of a video signal

Intermittent motion flying spot telecine

A dual range A/D converter includes a gain matching circuit for balancing the upper end of the transfer curves of the level-dependent dual A/D signal paths of the converter so as to control crossover between the paths. One path (high gain path) is provided with signal gain that is a nominal multiple of gain applied to the other path (low gain path). A digital comparator compares the digital code word output of flash A/D converters included in the respective paths, with the output from the high gain path being scaled down to correspond to the output from the low gain path. If a difference is detected, the upper ladder reference of the flash converter in the low gain path is adjusted until the respective gain difference becomes substantially an exact multiple. When this matching is combined with black level correction, which equalizes the lower end of the transfer curves, a fully self-calibrating dual range A/D converter is obtained.

Self calibrating dual range A/D converter

A flying spot telecine includes a control processor for generating and storing a MINIMUM GAIN REFERENCE value representing a minimum gain of each of a plurality of PMT sections which detect light transmitted by a film strip that is being scanned by a light spot. The control processor also generates and stores a MAXIMUM GAIN REFERENCE value representing a maximum gain of each of the plurality of PMT sections. A system gain control provides control signals to the plurality of PMT sections to control the voltage applied thereto. During subsequent operation of the telecine to modify control signals provided to each of the plurality of PMT sections dependent upon the stored MINIMUM GAIN REFERENCE and MAXIMUM GAIN REFERENCE value for the respective one of the plurality of PMT sections independently of the control signals provided to the others of the plurality of PMT sections.

Flying spot telecine and method of operating same

In a flying spot telecine used to generate video signals by scanning a film, the scanning raster is adjustable angularly relative to the film being scanned. The output video signal hence represents the image on the film but angularly displaced relative to the orientation of the film itself. Using this method angular and rotational picture effects can be generated without the need for expensive computer memory or complex processing of picture information. The method can be applied to produce similar angular and rotational effects in a film writer. In such a system, unexposed film is repeatedly scanned by the flying spot scanner, the beam of which is modulated in turn by R, G and B video signals.

Scanner with electronically variable raster to produce picture effects

In a flying spot telecine used to generate video signals by scanning a film, the scanning raster is adjustable angularly relative to the film being scanned. The output video signal hence represents the image on the film but angularly displaced relative to the orientation of the film itself. Using this method angular and rotational picture effects can be generated without the need for expensive computer memory or complex processing of picture information.

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Hertford, United Kingdom

Terence W Mead