Automatic correction of keystone distortion and other unwanted artifacts in projected images

Abstract

A system for manual or automatic correction of geometric or video image distortions introduced by projection onto obliquely angled or imperfect surfaces. Sensors may be disposed at the projector itself, at the projected image surface, or in a portable remote-control unit. Corrections may be applied as part of an original set-up process, or dynamically as the configuration changes. Image-stabilization techniques are utilized where applicable, as is the use of test patterns and the incorporation of “helper” signals into the video image. Tactile-sensing capabilities provide an interactive environment, and various packaging configurations for projection units and sensor provisions are disclosed.

1 . Projected image interaction apparatus, comprising:
 a device including a projector operative to project an image defining a display area onto a surface, and wherein the projected image includes textual or graphical imagery;   a sensor operative to view the projected image on the surface and any overlying objects interposed between the projector and the surface display area;   gesture recognition apparatus operative to recognize an overlying object interacting with the textual or graphical imagery in the projected image; and   a processor operative to interpret a recognized gesture and control the device or projected image in response to the interaction.   
     
     
         2 . The projected image interaction apparatus of  claim 1 , wherein:
 the projected image is a still or moving image; and   the gesture recognition apparatus is operative to recognize the position or movement of the overlying object.   
     
     
         3 . The projected image interaction apparatus of  claim 1 , wherein the object includes a human form. 
     
     
         4 . The projected image interaction apparatus of  claim 3 , wherein the object includes a finger, hand or other body part. 
     
     
         5 . The projected image interaction apparatus of  claim 4 , wherein:
 the projected image has x and y coordinates associated therewith; and   the processor is operative to compare the position or movement of the finger, hand or other body part to corresponding x and y coordinates associated with the projected image to control the device or the projected image.   
     
     
         6 . The projected image interaction apparatus of  claim 1 , wherein:
 the sensor is operative to detect infrared objects; and   the processor is operative to determine the position or movement of a finger, hand or other body part based upon infrared detection.   
     
     
         7 . The projected image interaction apparatus of  claim 1 , further including:
 a tactile sensor operative to generate a wireless signal if a point of the surface is touched by a user;   a wireless receiver operative to receive the wireless signal; and   apparatus operative to receive the image viewed by the sensor, determine coordinates of the point touched by the user in response to receipt of the wireless signal, compare the coordinates to coordinates of the projected image, and select a region of the projected image associated with the point touched by the user.   
     
     
         8 . The projected image interaction apparatus of  claim 7 , wherein the tactile sensor is worn by a user. 
     
     
         9 . The projected image interaction apparatus of  claim 7 , wherein the tactile sensor is worn on a finger of a user. 
     
     
         10 . The projected image interaction apparatus of  claim 7 , wherein the wireless signal is an optical, infrared or RF signal. 
     
     
         11 . The projected image interaction apparatus of  claim 1 , further including:
 a display buffer storing a raw image to be seen by a viewer, a projection buffer storing a version of the raw image to be projected onto the surface, and a sensor buffer storing an image of the projected image as viewed by the sensor; and   wherein the processor is operative to recognize an interaction by comparing an image stored in the sensor buffer to an image stored in the display buffer.   
     
     
         12 . The projected image interaction apparatus of  claim 11 , wherein the sensor is operative to view an area of the surface which is larger than the display area of the projected image and store an image of the larger area in the sensor buffer. 
     
     
         13 . The projected image interaction apparatus of  claim 1 , wherein the projection buffer is selectively turned off or the frame rate is reduced to facilitate movement compensation. 
     
     
         14 . The projected image interaction apparatus of  claim 1 , wherein the device is a smartphone. 
     
     
         15 . The projected image interaction apparatus of  claim 1 , wherein the sensor forms part of the device. 
     
     
         16 . The projected image interaction apparatus of  claim 1 , wherein the sensor is a video camera.