Polaroid Corporation

Allan C Green

David D Pape

Julian G Bullitt

Paul W Ernest

Mary Deshon

Arnold L Buck

An improved electronic still imaging camera is described wherein electronic voltage values representative of an image are transformed according to an optimum tone scale mapping gamma curve. The gamma curve utilizes a subjective element along with an element associated with scene reflectivity to optimize tone scale variations according to steps in an analog-to-digital converter while reducing contouring in the image.

Optimal tone scale mapping in electronic cameras

Improved digital image processing circuitry for sharpening edges and details of a recorded image digitally while minimizing the amplification of noise in the input recorded image provides an output recorded image which is the sum of chrominance signals processed by color processing circuitry and luminance signals processed by color processing circuitry and sharpness circuitry. Input recorded images are provided for concurrent parallel processing by both the color processing circuitry and the sharpening circuitry in a manner whereby the color processing circuitry generates low spatial frequency luminance signals and the sharpness circuitry generates high spatial frequency luminance signals both of which are subsequently combined to provide an output signal in which the amplitude of the high spatial frequency noise component associated therewith is minimized.

Digital image processing circuitry

An improved system for transferring still image defining high resolution data from a solid state sensor in an electronic imaging camera in a manner whereby the image data is decimated by a select factor and the rate of transfer decreased to accommodate the recording of high resolution still images by a conventional video storage system.

System and method of providing images from solid state sensor

A method and apparatus for exposure control of electronic imaging cameras capable of video and still modes of operation and having an automatic variable aperture diaphragm to control image light passing to a sensor during the video mode of operation. Relatively short exposure time intervals are attained in the still mode of operation by attenuating light passing to the sensor during the video mode so that the aperture to which the variable aperture diaphragm is set is increased over that to which it would normally be adjusted during video operation. Upon conversion to the still mode, the filter attenuation is rapidly removed resulting in a correct aperture setting for the relatively shorter still mode exposure time intervals. In the video mode, electronic shutter operation is effected in the conventional manner. In the still mode of operation, the exposure time interval is established either by a combination of electronic shutter operation and mechanical shutter operation or by mechanical operation alone. A shutter mechanism is disclosed in which the light attenuating and exposure terminating functions are combined.

Exposure control system for dual mode electronic imaging camera

Apparatus for encoding electronic still image information signals to a form suitable for recording on a conventional recording media by dividing the electronic information signals into a plurality of groups of electronic information signals wherein each group corresponds to a plurality of different picture elements of the still image. Decoding apparatus is also provided for recording the electronic information signals from the different groups into their original order so as to enable reconstruction of the still image. The encoding apparatus may also be adapted to transmit conventional electronic video image information signals interspersed with the selectively encoded electronic still image information signals for recording on the conventional storage media. The decoding apparatus operates to separate the electronic still image information signals from the electronic video image information signals prior to decoding.

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Framingham, MA, United States of America

Allan C Green