ENHANCED CONTRAST FOR OBJECT DETECTION AND CHARACTERIZATION BY OPTICAL IMAGING USING FORMED DIFFERENCE IMAGES

摘要

Enhanced contrast between an object of interest and background surfaces visible in an image is provided using controlled lighting directed at the object. Exploiting the falloff of light intensity with distance, a light source (or multiple light sources), such as an infrared light source, can be positioned near one or more cameras to shine light onto the object while the camera(s) capture images. The captured images can be analyzed to distinguish object pixels from background pixels.

主权项

1. A method for analyzing captured images, the method comprising:
capturing a first plurality of digital images of a field of view using a camera and at least one light source; identifying pixels of the first plurality of digital images that correspond to an object rather than to a background based on differences between first, second and third digital images captured by the capturing, the identifying including:
forming a first difference image based upon a difference between the first digital image captured by the capturing and the second digital image captured by the capturing;forming a second difference image based upon the difference between the second digital image captured by the capturing and the third digital image captured by the capturing; anddetermining a third difference image, wherein each of one or more pixels of the third difference image comprises a pixel of a smaller pixel value between a corresponding pixel in the first difference image and a corresponding pixel in the second difference image, wherein the third difference image identifies the pixels that correspond to the object; and constructing a model of the object based on the identified pixels, the model including a position and a shape of the object.