Showing papers on "Object detection published in 1971"
TL;DR: Simple sets of parallel operations are described which can be used to detect texture edges, "spots," and "streaks" in digitized pictures and it is shown that a composite output is constructed in which edges between differently textured regions are detected, and isolated objects are also detected, but the objects composing the textures are ignored.
Abstract: Simple sets of parallel operations are described which can be used to detect texture edges, "spots," and "streaks" in digitized pictures. It is shown that, by comparing the outputs of the operations corresponding to (e.g.,) edges of different sizes, one can construct a composite output in which edges between differently textured regions are detected, and isolated objects are also detected, but the objects composing the textures are ignored. Relationships between this class of picture processing operations and the Gestalt psychologists' laws of pictorial pattern organization are also discussed.
811 citations
Patent•
30 Sep 1971
TL;DR: In this article, an object detection system using an acoustic transducer for generating compressional waves in the air and detecting return pulses from an object lying within the detection zone is described.
Abstract: An object detection system is disclosed which makes use of an acoustic transducer for generating compressional waves in the air and detecting return pulses from an object lying within the detection zone. A transducer mounting system includes a transducer slug mounted for generating acoustic waves from both ends of the slug. The antenna system includes a reflector housing adapted to accommodate variable surfaces for controlling the energy pattern. Details of the electronic circuitry associated with the transducer mounting system and a door opening system are disclosed.
25 citations
TL;DR: With minimality of the average time to object detection as the measure of policy goodness, the paper formulates and analyzes a search problem for finding a stationary object hidden in one of N specified regions with a priori probability of p i, and obtains optimality conditions and improvement algorithms.
Abstract: This paper formulates and analyzes a search problem for finding a stationary object hidden in one of N specified regions with a priori probability $p_i ,\sum
olimits_{i = 1}^N {p_i = 1} $. A searcher looks for the object by repeated searches and switches of regions. Before a search begins in a new region i, a certain time (called switch time $c_i $) is necessarily wasted. The probability of object detection in region i is related to the accumulated visit time x by a probability distribution function $Q_i (x)$. With minimality of the average time to object detection as the measure of policy goodness, we have obtained optimality conditions and improvement algorithms. More detailed properties are presented for special cases of restricted $Q(x)$ and zero switch times.
13 citations
TL;DR: In this paper, the authors considered two-channel detection systems using a sidelobe blanking logic when a nonfluctuating target was present and proposed an adaptive threshold procedure to ensure the probability of false alarm at any given resolution cell is maintained constant, even though the input clutter level may vary from cell to cell or from beam position to beam position.
Abstract: In an earlier paper, Maisel [6] considered two-channel detection systems using a sidelobe blanking logic when a nonfluctuating target was present. This paper is an extension of the earlier work to include fluctuating targets. The Swerling I, II, III, and IV models are considered when single-pulse detection is of interest. An adaptive threshold procedure is also briefly discussed whereby the probability of false alarm at any given resolution cell is maintained constant, even though the input clutter level may vary from cell to cell or from beam position to beam position. Useful data are presented for detection probabilities in the range 0.5 to 0.9, for false alarm probabilities in the range 104 to 10-8, and for a false detection probability of 0.1 for a sidelobe target yielding an apparent signal to total noise power density ratio of 13.0 dB in the main beam receiver.
10 citations
Patent•
30 Sep 1971
TL;DR: In this paper, an object detection system using an acoustic transducer for generating compressional waves in the air and detecting return pulses from an object lying within the detection zone is described.
Abstract: An object detection system is disclosed which makes use of an acoustic transducer for generating compressional waves in the air and detecting return pulses from an object lying within the detection zone. A transducer mounting system includes a transducer slug mounted for generating acoustic waves from both ends of the slug. The antenna system includes a reflector housing adapted to accommodate variable surfaces for controlling the energy pattern. Details of the electronic circuitry associated with the transducer mounting system and a door opening system are disclosed.
9 citations