Perspective improvement for image and video applications

Abstract

A system and method for reducing distance-based distortion in a camera image of an object, where the distanced-based distortion is due to differences in distance from the camera to different parts of the object. In one approach, the distortion is reduced by estimating distances to different parts of the object and then generating a reprojected image of the object dependent upon the estimated distances and upon a virtual viewpoint that is more distant than the camera from the object. In a further approach, the image is warped such that points in the image match corresponding points in one or more stored templates. In a still further approach, if excessive distortion is present in the image, the camera zoom is increased and a magnified image is displayed, prompting a person to move farther from the camera thereby reducing the distortion.

1 . A method for reducing distance-based distortion in an image of an object, the image being captured by a camera, where the distance-based distortion is due to differences in distance from the camera to different parts of the object, the method comprising:
 for each template of at least one template of the object, a camera determining a set of warping parameters that relate points in the image to corresponding points in the template of the object;   selecting by the camera from the set of warping parameters for each of the at least one template, the set of warping parameters that results in the best match between the warped image and the corresponding template; and   warping, by the camera, the image using the selected set of warping parameters.   
     
     
         2 . A method in accordance with  claim 1 , wherein the at least one template of the object comprise a plurality of views of the object. 
     
     
         3 . A method in accordance with  claim 1 , wherein the object is a face and wherein the image comprises an image from a sequence of video images. 
     
     
         4 . A system for reducing distance-based distortion in an image of an object, the system comprising:
 a camera operable to capture an image of the object;   an estimation element operable to estimate distance-based distortion in the captured image;   a processing element operable to process the captured image to reduce distance-based distortion in the captured image.   
     
     
         5 . A system in accordance with  claim 4 , wherein the estimation element is operable to estimate the distance to at least one region of the object. 
     
     
         6 . A system in accordance with  claim 4 , wherein the estimation element is operable to estimate the size, in the image, of a specified feature of the object. 
     
     
         7 . A system in accordance with  claim 4 , wherein the estimation element comprises an active distance measuring means. 
     
     
         8 . A system in accordance with  claim 4 , wherein the estimation element is operable to estimate the amount of warping needed to match points in the captured image to corresponding points in a previously stored image. 
     
     
         9 . A system in accordance with  claim 4 , wherein the processing element is operable to warp the captured image such that points in the captured image match points in a previously stored image. 
     
     
         10 . A system in accordance with  claim 4 , wherein the processing element is operable to reproject the captured image to simulate a more distant camera view point. 
     
     
         11 . A system for reducing distance-based distortion in an image of an object, the system comprising:
 a camera operable to capture an image of the object;   a means for estimating distance-based distortion in the captured image;   a means for processing the captured image to reduce distance-based distortion in the captured image.   
     
     
         12 . A system in accordance with  claim 11 , wherein the means for estimating distance-based distortion in the captured image comprises a means for estimating the distance to at least one region of the object. 
     
     
         13 . A system in accordance with  claim 11 , wherein the means for estimating the distance to at least one region of the object comprises a means for estimating the size, in the image, of a specified feature of the object. 
     
     
         14 . A system in accordance with  claim 11 , wherein the means for estimating the distance to at least one region of the object comprises an active distance measuring means. 
     
     
         15 . A system in accordance with  claim 11 , wherein the means for estimating distance-based distortion in the captured image comprises a means for estimating the amount of warping needed to match points in the captured image to corresponding points in a previously stored image. 
     
     
         16 . A system in accordance with  claim 11 , wherein the means for processing the captured image to reduce distance-based distortion in the captured image comprises a means for warping the captured image such that points in the captured image match points in a previously stored image. 
     
     
         17 . A system in accordance with  claim 11 , wherein the means for processing the captured image to reduce distance-based distortion in the captured image comprises a means for reprojecting the captured image to simulate a more distant camera view point.