Analytics-modulated coding of surveillance video

Abstract

A method and apparatus for encoding surveillance video where one or more regions of interest are identified and the encoding parameter values associated with those regions are specified in accordance with intermediate outputs of a video analytics process. Such an analytics-modulated video compression approach allows the coding process to adapt dynamically based on the content of the surveillance images. In this manner, the fidelity of the region of interest is increased relative to that of a background region such that the coding efficiency is improved, including instances when no target objects appear in the scene. Better compression results can be achieved by assigning different coding priority levels to different types of detected objects.

What is claimed is: 
     
         1 . A non-transitory processor-readable medium storing code representing instructions to be executed by a processor, the code comprising code to cause the processor to:
 receive a group of pictures (GOP) including (1) a first video frame having a plurality of pixels and (2) a second video frame having a plurality of pixels;   segment from the first video frame a foreground object from a background, the foreground object of the first video frame having pixels from the plurality of pixels of the first video frame organized into a pixel blob;   classify the pixel blob into a class from a plurality of predefined classes;   track motion information associated with the pixel blob in the first video frame and the second video frame;   code at least one of the first video frame or the second video frame to produce a coded video frame based at least in part on (1) a weight assigned to the class, or (2) the motion information.   send a representation of the coded video frame.   
     
     
         2 . The non-transitory processor-readable medium of  claim 1 , wherein the motion information includes a speed associated with the foreground object, the code further comprising code to cause the processor to:
 define a search area of a prediction search window based at least in part on the speed; and   identify in a third video frame the foreground object based on the search area of the prediction search window.   
     
     
         3 . The non-transitory processor-readable medium of  claim 1 , wherein the code to cause the processor to code at least one of the first video frame or the second video frame includes code to cause the processor to code at least one of the first video frame or the second video frame based on a prediction block of pixels. 
     
     
         4 . The non-transitory processor-readable medium of  claim 1 , wherein the code to cause the processor to classify includes code to cause the processor to classify the pixel blob into the class based at least in part on at least one of an aspect ratio of the pixel blob, a histogram associated with the pixel blob, or an outline of the pixel blob. 
     
     
         5 . The non-transitory processor-readable medium of  claim 1 , the code further comprising code to cause the processor to:
 define a search area of a prediction search window based at least in part on the motion information; and   adjust the search area of the prediction search window based on moving portions within the foreground object.   
     
     
         6 . The non-transitory processor-readable medium of  claim 1 , wherein:
 the code to cause the processor to segment includes code to cause the processor to segment from the first video frame a plurality of foreground objects including the foreground object,   the code to cause the processor to code includes code to cause the processor to code the first video frame based on a quantity of foreground objects from the plurality of foreground objects within the first video frame.   
     
     
         7 . The non-transitory processor-readable medium of  claim 1 , the code further comprising code to cause the processor to:
 define a search area of a prediction search window based on the motion information;   identify in a third video frame a prediction block of pixels associated with the pixel blob of the first video frame based on the prediction search window, the search area having a search area associated with a coding priority assigned to the class.   
     
     
         8 . The non-transitory processor-readable medium of  claim 1 , the code further comprising code to cause the processor to:
 define a first search area of a prediction search window based at least in part on the motion information;   adjust the first search area of the prediction search window based on moving portions within the foreground object; and   identify in a third video frame a prediction block of pixels associated with the pixel blob of the first video frame based on the prediction search window, the search area having a search area associated with a coding priority assigned to the class.