Applied Materials, Inc.
Methods and apparatus for absolute and relative depth measurements using camera focus distance

Abstract:

A depth measuring apparatus includes a camera assembly, a position sensor, and a controller. The camera assembly is configured to capture a plurality of images of a target at a plurality of distances from the target. The position sensor is configured to capture, for each of the plurality of images, corresponding position data associated with a relative distance between the camera assembly and the target. The controller is configured to, for each of a plurality of regions within the plurality of images: determine corresponding gradient values within the plurality of images; determine a corresponding maximum gradient value from the corresponding gradient values; and determine a depth measurement for the region based on the corresponding maximum gradient and the corresponding position data captured for an image from the plurality of images that includes the corresponding maximum gradient.