Noise camera, server for processing documentary evidence from noise-cameras and methods

Abstract

A noise camera comprises a plurality of audio detectors such as microphones, which are spatially disposed with respect to a tracking camera. The plurality of audio detectors may be arranged to detect a location of a noise source in a field of view of the tracking camera, thereby allowing identification of a source of noise such as a vehicle emitting noise exceeding a predetermined threshold such as a legal limit. The noise camera may comprise one or more detection cameras for identifying a noise source by techniques such as number plate recognition for the example of a vehicle. A location of a noise source in the field of view of the tracking camera is determined from a time difference of arrival of the noise from the noise source detected by a plurality of the audio detectors. The time difference of arrival indicating an angle of the noise from the tracking camera may be mapped into video captured with the field of view of the tracking camera as one or more pixel location values. Documentary evidence generated from the noise camera can include the tracking video, noise source pixel location values comprising, for each of one or more tracking images of the tracking video, an indication of a location of a pixel of a dominant noise source in the tracking video. The documentary evidence may be processed to identify a path of the dominant noise source in the tracking video from the noise source pixel location values. From the path, a detection time at which the path of the dominant noise source in the tracking video is closest to a detection point in a field of view of a detection camera is determined. The noise source such as a vehicle is identified from images at the detection time.