Polaroid Corporation

James L Burkhardt

John J McCann

William R Wray

Munib Abdulwahab

A color transform enables color-image information to be recorded, displayed and otherwise processed with exacting control of color relative to a selected display. Apparatus implementing the transform enables a single-exposure photographic print of image information produced in pre-press equipment to predict with accuracy an ink-on-paper print of that information. Color-image information is transformed with a technique that produces output information for each output color component or other parameter at each point in response to up to all input parameters at that point. The technique includes scaling, normalizing and linearizing steps, and may include selecting a uniform color space for mapping the color response of the object (film) medium with the color response of the reference (print) medium. The output information may include approximate transform values and finalizing values. The technique can be implemented for real-time conversion with look-up tables storing approximate transform values and storing interpolation factors, including gradient values, for computing finalizing values.

Method of and apparatus for transforming color image data on the basis

A signal processor for selective use with a conventional color television receiver for modifying the color image displayed on the screen of the receiver in order to enable a color photograph to be made by directly exposing a photosensitive material to the modified color image displayed on the screen of the receiver such that the photographic image is of an appearance substantially corresponding to the appearance of the image otherwise displayed on the screen of the receiver when the signal processor is not in use.

Processor for enhancing video signals for photographic reproduction

An oscillator unit having a charge storage device periodically rapidly charged through a small resistor and slowly discharged through a large resistor under control of a comparator for producing an oscillatory output and a switch actuatable by means of a frequency controlled zero-crossing multiplier to selectively discharge the storage device and thereby repeatedly resynchronize the oscillator unit with the frequency input to the multiplier.

Synchronizable oscillator

Flutter in an audio signal recorded on a magnetic tape is reduced by sampling the audio at a rate determined by the frequency of a reference signal also recorded on the tape, reading the samples into respective cells of a memory, and reading out respective cells of the memory at a substantially constant rate that is independent of rapidly changing short duration variations in tape speed. The read-out rate is isolated from tape speed by introducing a time delay between the read-in and read-out of the same sample, the amount of the delay changing in accordance with differences in speed between the tape and a fixed reference. Changes in the delay between read-in and read-out of the same sample generate an error signal that is used to control the speed of the capstan motor that drives the tape past a transducer.

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Watertown, MA, United States of America

James L Burkhardt