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AssigneeLucasArts Entertainment Company
InventorsTomlinson Holman, David Schnuelle
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A test signal for enabling control of picture fidelity in a distribution system for distributing a video signal that has a vertical interval including a number of lines. The test signal comprises plural luminance levels for testing luminance linearity. The luminance levels have a non-linear level relationship with respect to one another. Each luminance level has a predetermined level. The test signal may additionally include a chrominance component for testing differential gain and phase. The chrominance component has a predetermined amplitude and a predetermined phase corresponding to flesh tone. In a method of enabling control of picture fidelity in a distribution system for distributing a video signal, the above test signal is provided at a source stage and is inserted into at least part of a selected line in the vertical interval of the video signal. At a later stage in the distribution system, at least two of the luminance levels in the test signal in the vertical interval of the video signal are measured, each of the at least two measured luminance level are compared with its corresponding predetermined luminance level to provide at least two luminance errors, and luminance linearity in the source stage and/or the later stage is changed to correct the luminance errors. Chrominance gain and phase errors may also be determined, and differential gain and phase changed to correct the chrominance gain and phase errors.
A test signal for use in detecting errors in low-level luminance linearity in a distribution system for distributing a video signal having a vertical interval including a number of lines, the test signal comprising:
A method for detecting low-level luminance errors in a distribution system for distributing a video signal having a vertical interval including a number of lines, the distribution system having a source stage and a later stage, the method comprising the steps of, at the source stage:
An apparatus for inserting a test signal for detecting errors in low-level luminance linearity into a video signal, the video signal having a vertical interval including a number of lines, and a luminance component, the apparatus comprising:
An apparatus for correcting low-level luminance errors in a video signal having on at least part of a selected line in the vertical interval thereof a test signal including plural luminance levels, the luminance levels having a non-linear level relationship with respect to one another, each luminance level having a predetermined level, more than two of the luminance levels being at a luminance level below 20 IRE units;
Dependencies are inferred from the claim text.