Range camera
AssigneeMicrosoft Technology Licensing, LLC
InventorsMichael Anthony Hall, Kameron Rausch, Abdelrehim Ahmed, Beibei Cheng, Ben Walker, Jonathan Hoof, Daniel Kennett
Life of this patent
Estimating the term…
Abstract
An active illumination range camera that acquires a range and a picture image of a scene and provides a reflectance for a feature in the scene responsive to a distance for the feature provided by the range image, a registered irradiance for the feature provided by the picture image and registered irradiance for a region of a calibration surface corresponding to the feature provided by an image of the calibration surface acquired by the range camera.
Claims23
A range camera operable to determine distances to and reflectance for features of a scene that the range camera images, the range camera comprising:
- a light source operable to transmit light to illuminate a scene that the range camera images;
- a photosensor having a plurality of light sensitive pixels;
- optics having an optical axis and optical center configured to receive light reflected from the transmitted light by features in the scene and image the reflected light on the plurality of pixels, each of which pixel of the plurality of pixels registers reflected light from a feature of the scene that the optics images on the pixel to provide a registered scene irradiance (RSI) for the feature;
- a calibration image comprising a registered calibration irradiance (RCI) for each of the plurality of light sensitive pixels that provides a measure of irradiance that the pixel registers responsive to light reflected from light transmitted by the light source by a region of a calibration surface having known shape, reflectance, and location that the range camera images on the pixel;
- and
- a controller operable to determine a reflectance for a feature of the scene imaged on a first pixel of the plurality of pixels responsive to the RSI for the feature and an RCI for a region of the calibration surface imaged on a second pixel of the plurality of pixels corresponding to the feature imaged on the first pixel.
A method of determining reflectance for a feature of a scene, the method comprising:
- using an active lighting range camera to acquire a range image and a picture image of the scene responsive to light transmitted by the range camera to illuminate the scene that is reflected by features in the scene back to the range camera;
- determining a location of the feature in the FOV responsive to the range image;
- determining registered irradiance of the range camera for light reflected from the transmitted light by the feature responsive to the picture image;
- determining a corresponding region of a calibration surface imaged in a calibration image acquired by the range camera;
- determining registered irradiance of the range camera for light reflected from the transmitted light by the corresponding region responsive to the calibration image;
- and
- using the determined registered irradiances from the feature and the corresponding calibration region and known reflectance of the calibration surface to determine the reflectance of the feature.
A range camera operable to determine distances to and reflectance for features of a scene that the range camera images, the range camera comprising:
- a light source operable to transmit light to illuminate a scene that the range camera images;
- a photosensor having a plurality of light sensitive pixels;
- a look up table (LUT) having for each pixel of the plurality of light sensitive pixels a set of values for a first feature having known reflectance that is imaged on the pixel from a known first distance from the camera and illuminated by light at known intensity from the light source, the set of values comprising a registered calibration irradiance (RCI) for light reflected by the first feature from the illuminating light;
- and
- a controller that, determines a reflectance of a second feature imaged on the pixel from a second distance responsive to a square of the ratio of the first distance divided by the second distance, the RCI, and a registered scene irradiance (RSI) that the pixel provides for light from the light source that is reflected by the second feature and imaged on the pixel.
Dependencies are inferred from the claim text.