U.S. Robotics Access Corp.

Computer Microfilm International Corporation

David L Smith

Kwan Kin Truong

Craig H Richardson

John J Proctor

Chris J Hodges

Philip A DesJardins

Gerald E O'Brien

Mark M Baldassari

Dwight H Smith

John M Jamieson

A method and an apparatus for encoding an image signal. The apparatus includes an acquisition module disposed to receive the image signal. A first processor is coupled to the acquisition module. At least one encoder processor is coupled to the first processor. The at least one encoder processor produces an encoded image signal under control of the first processor. The method includes the steps of converting an input image signal into a predetermined digital format and transferring the digital format image signal to at least one encoder processor. The method further includes the step of applying, at the at least one encoder processor, a hierarchical vector quantization compression algorithm to the digitized image signal. At the next step, a resultant encoded bit stream generated by the application of the algorithm is collected. The method and apparatus of the present invention may be used in conjunction with an ordinary modem to transmit and/or receive audio, video sequences or still images.

Method for generating a compressed video signal

Method for adjusting the quality of a video coder

Video encoder/decoder system

A microfilm display device is responsive to a film address signal and controlled by a microprocessor to locate a desired film and select a film image for display on a cathode-ray terminal. The film image is converted to a video signal for display on the terminal. The video signal is used for fine positioning of the raster on a flying spot scanner which illuminates the film.

Image positioning apparatus

A film card for use in an automatic microfilm display apparatus has a plurality of image frames, each bearing a marker image. One of the frames is a reference frame and includes only the marker image. The reference frame can be used for accurate positioning of a raster pattern on the remaining frames.

Film card with reference frame

A film card selection device for use in an automatic microfilm display apparatus is provided with a switch for sensing that a film card has been selected. A counter counts the number of drive gear teeth passing a selected point after selection of a film card so that the apparatus can be stopped with the selected card in position for retrieval.

Card selector device

A film card retrieval device for use in an automatic microfilm display apparatus is provided with a switch for sensing that a film card has been retrieved. In the event the device fails to retrieve a film card, the absence of a switch output signal causes the control apparatus to repeat the card retrieval routine.

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Atlanta, GA, United States of America

David L Smith