Honeywell G.m.b.h.

University of Minnesota

Robert C Fitch

Richard A Fundakowski

Patrenahalli M Narendra

Meletios Geokezas

Panos G Michalopoulos

Pat M Narendra

A vehicle detection system for providing data characteristic of traffic conditions includes a camera overlooking a roadway section for providing video signals representative of the field (traffic scene), and a digitizer for digitizing these signals and providing successive arrays of pixels (picture elements) characteristic of the field at successive points in space and time. A video monitor coupled to the camera provides a visual image of the field of view. Through use of a terminal and in conjunction with the monitor, an operator controls a formatter so as to select a subarray of pixels corresponding to specific sections in the field of view. A microprocessor then processes the intensity values representative of the selected portion of the field of view in accordance with spatial and/or temporal processing methods to generate data characteristic of the presence and passage of vehicles. This data can be utilized for real-time traffic surveillance and control, or stored in memory for subsequent processing and evaluation of traffic flow conditions.

Vehicle detection through image processing for traffic surveillance and

First and second signals are selected from a plurality of sequentially fed, a.c. coupled signals. A difference signal which is the difference between the first and second signal is generated. The times during which the first signal exceeds the second, and during which the second signal exceeds the first, are determined. The larger of these two times is selected and an average of the difference signal over this larger time is generated. The average is added to the second signal. Means for implementing these steps, including an all analog embodiment are disclosed.

Synthetic d.c. restoration of a.c. coupled signals

A local area contrast enhancement scheme for a video display includes a two dimensional recursive filter to obtain a moving average of the intensity variations in all areas of the display. This moving average is subtracted from the original signal to produce a signal which contains only local variations and this latter signal is expanded to increase the display contrast. The local area contrast enhancement scheme allows low contrast details to be perceived and permits hands-off operation of the display under varying scene conditions. The recursive filter approach results in a simple implementation of the enhancement scheme with both analog and digital circuitry.

Growing community of inventors

Roseville, MN, United States of America

Robert C Fitch