ApplicationNo. 05/700852 filed on 06/29/1976
US Classes:358/520, Hue, saturation and luminance358/507Cathode-ray tube
ExaminersPrimary: Richardson, Robert L.
Attorney, Agent or Firm
International ClassesH04N 9/79 (20060101)
H04N 9/11 (20060101)
H04N 9/82 (20060101)
G11B 27/034 (20060101)
G11B 27/031 (20060101)
G11B 27/024 (20060101)
G11B 27/02 (20060101)
G11B 27/022 (20060101)
AbstractThe system and method are used to convert images on motion picture film or slides to video signals. Color corrections in the video signals are made by adjusting not only the color balance, but also the color hue and saturation, as well as the separate component parts of the luminance signal. During the first phase of operation, the "load" mode, a "standard" set of color correction values is selected so as to provide a video picture which is pleasing to the eye. Then the whole film is color-corrected by providing incremental adjustment signals to be added to or subtracted from the "standard" values for each different scene on the film. The incremental adjustment values are stored in the memory of a digital computer. A frame counter provides a count of the frame at which a color correction is made. Furthermore, each color correction of a frame is given an "event" number. The event and frame numbers are stored together with the adjustment values for each scene or frame. During the second phase of operation, the "run" mode, a video tape recording of the color-corrected video signals is produced by re-running the motion picture film through the system, while reference values for the color corrections, together with incremental values previously stored, are read out, added together, and sent through a film chain. The color-corrected video signals from the film chain are sent to a video tape recorder which records them in a continuous record on tape. If desired, the adjustment values for the color components can be read out of the digital computer memory and stored in a more permanent storage medium such as punched paper tape. Then, at a later date, the signals can be read back into the digital computer, so that the color corrections can be used again. At this time, a new reference signal can be selected and stored in the computer to be combined with the adjustment signals. This permits adjusting the reference signal to compensate for changes due to aging of components in the film chain and elsewhere in the system, thus making it practical to store color correction information for relatively long periods of time without significant degradation of quality of the resulting tape recording. The system will color-correct motion picture film or still slides. Moreover, the speeds of the projectors are variable. Also, during color correction, the motion picture film is stopped so as to provide a stationary display of the images from a selected frame. In order to prevent degradation of the sharpness of the images due to these speed variations, an image enhancement circuit is provided which produces image enhancement in an amount which varies directly with the projector speed.