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Showing papers on "Object detection published in 1975"


Proceedings Article
03 Sep 1975
TL;DR: A self-scaling local edge detector that can be applied in parallel on a picture is described and clustering algorithms and sequential boundary following algorithms process the edge data to local images of objects and generate a data structure that represents the imaged objects.
Abstract: A solution to the problem of automatic location of objects in digital pictures by computer is presented. A self-scaling local edge detector which can be applied in parallel on a picture is described. Clustering algorithms and boundary following algorithms which are sequential in nature process the edge data to locate images of objects and generate data structure which represents the imaged objects.

163 citations


Journal ArticleDOI
TL;DR: In this paper, a simple algorithm is developed which yields the velocity, as a function of time, of an object moving against a complicated background, which relies on monitoring magnitude and phase of two prominent spatial Fourier components.
Abstract: The passive detection of velocities of objects moving transverse to the optical viewing axis is discussed from the standpoint of the spatial Fourier transform of the image. A simple algorithm is developed which yields the velocity, as a function of time, of an object moving against a complicated background. This algorithm relies on monitoring magnitude and phase of two prominent spatial Fourier components. Measurement of the Fourier components is most simply accomplished with the direct electronic Fourier transform (DEFT) sensor. This device employs coupling between the image intensity, surface acoustic waves, and electron current in a CdS film to decompose the image into Fourier components. Experimental results show strong confirmation between theory and experiment. The paper concludes with a brief comparison of the DEFT implementation versus other systems in terms of speed, sensitivity, and cost.

10 citations


Journal ArticleDOI
TL;DR: In this paper, a simple threshold detection scheme is used which decides that an object is present at a location when the return at the corresponding time crosses a threshold, then a single object will give rise to many detections.
Abstract: The uniformly spaced burst waveform provides excellent clutter rejection in cases where the clutter and targets are separated in velocity. However, it has the major disadvantage that an object at one range (at or near the search velocity) will give returns up and down range from the search range. If a simple threshold detection scheme is used which decides that an object is present at a location when the return at the corresponding time crosses a threshold, then a single object will give rise to many detections. (We shall call the detections at the ranges other than the true range of the object ambiguous detections, or ambiguities.) There are two classes of techniques to remove these ambiguities: those operating with a single transmission and those requiring additional transmissions. This correspondence considers the coincidence detection procedure which requires the transmission of two bursts with different pulse spacings. The detection and ambiguity removal performance of this algorithm is considered in detail for the case of scintillating targets.

1 citations