Showing papers on "Aerial image published in 1981"

Optical assembly for projection television receiver

Abstract: A novel optical assembly is disclosed for use in an ultra-compact, jack-in-the-box projection television receiver. The stationary optical assembly is permanently installed in a lower portion of the cabinet for forming a television image, and projecting an aerial image of the television image upwardly a predetermined image projection distance along an optical path folded by optical path folding means. The receiver includes a unitary optical assembly having a viewing screen selectively storable in the cabinet and elevatable therefrom for receiving and displaying the image. The stationary optical assembly comprises the following, in combination: an image source means for forming the television image, a cathode ray tube holding assembly, and mirror means to reflect the aerial image steeply upward along the folded optical path. Also included are chassis means for receiving and supporting the image source means, CRT holding assembly, and mirror means. The optical assembly according to the invention may also find application in a receiver in which the unitary optical assembly is fixed in permanent elevation from the receiver cabinet.

Macula-disc camera with improved resolution

Abstract: A macula-disc camera records the first aerial image of the patient's fundus to provide an actual increase in resolution of retinal detail not obtainable by merely magnifying this image with the recording optics An array of optical fibers surrounds the contact lens to illuminate a limied field of the fundus, on the order of 18° A high degree of contrast is achieved by tightly separating the observation and illumination beams throughout the lens of the cornea and crystalline lens Magnification, is on the order of 68 times

Optical system for projection television

Abstract: A projection optical system is disclosed that is protractible and retractible within a narrow spatial column for emerging from and nesting in a cabinet of an ultra-compact, rear-projection television receiver. The system comprises in combination a stationary optical assembly permanently enclosed in a lower portion of the cabinet and having image projection means and first mirror means. A protractible optical assembly is elevatable as a unit from the cabinet; the assembly includes a mirror and a rear projection screen. The mirror and screen are at angles effective to reflect and receive, respectively, an aerial image of the television image formed by the image projection means of the stationary optical assembly. The angles are also effective for nesting the mirror and the screen with components of the stationary optical assembly. The optical system, when retracted and nested is overall depth-wise-shallow and the receiver is as compact as a conventional, large-screen console television receiver. When the system is protracted within the narrow spatial column the receiver remains depth-wise-shallow, yet it is capable of displaying an image with an area greater than three times the image area of the conventional, large-screen console television receiver.

Reasoning about images: using meta-knowledge in aerial image understanding

Abstract: Image Understanding (I.U.) shares with Artificial Intelligence the need for mechanisms of using knowledge to control computation. In I.U., this knowledge takes the form of prior knowledge about objects and knowledge gained from doing the computations themselves. This paper presents an approach to the general I.U. problem and a specific program for locating buildings in aerial photographs. Prior knowledge is stored as an Appearance Model, which represents the appearances of possible buildings. A three stage program generates operator and parameter sequences to achieve recognition. Each level uses partial results from below to 1) search parameters for the best match, 2) infer obscuring image conditions and deal with them, and 3) infer high-level conditions such as the presence of occluding objects. This use of partial results is a kind of "metaknowledge", enabling the program to evaluate its progress and change hypotheses and computations accordingly.

Image Coding System Using an Adaptive DPCM

Abstract: We are trying to build a real time transmitter for large scale aerial digital image (5 000 × 5 000 pels) coded on 32 greys levels (5 bits) making a bit rate reduction of the transmitted information for a human interpretation