Incremental update for background model thresholds

摘要

Techniques are disclosed for creating a background model of a scene using both a pixel based approach and a context based approach. The combined approach provides an effective technique for segmenting scene foreground from background in frames of a video stream. Further, this approach can scale to process large numbers of camera feeds simultaneously, e.g., using parallel processing architectures, while still generating an accurate background model. Further, using both a pixel based approach and context based approach ensures that the video analytics system can effectively and efficiently respond to changes in a scene, without overly increasing computational complexity. In addition, techniques are disclosed for updating the background model, from frame-to-frame, by absorbing foreground pixels into the background model via an absorption window, and dynamically updating background/foreground thresholds.

主权项

1. A computer-implemented method for updating a background model associated with a scene depicted in a sequence of video frames captured by a video camera, the method comprising:
receiving image data for a current video frame, wherein the image data classifies each pixel in the current video frame as depicting either foreground or background; and for each pixel in the current video frame classified as depicting scene background, updating corresponding pixel data in the background model based on one or more color channel values of the pixel in the current video frame, wherein the pixel data includes (i) a distribution modeling each color channel value based on observed color channel values for the pixel in the sequence of video frames and (ii) a mean and a variance associated with the distribution for each color channel and wherein updating the corresponding pixel data in the background model based on the one or more color channel values of the pixel in the current video frame comprises, for each of the one or more color channels:
determining a difference between the color channel value in the current video frame and the mean for the color channel,updating the mean for the color channel based on the difference and a user-specified weight, andupdating the variance for the color channel based on the difference and the weight.