Method and system for detecting obstructive object at projected locations within images

Abstract

A method for controlling a movable object includes acquiring one or more images captured by an imaging device borne by the movable object and at least partially blocked by an obstructive object attached to the movable object, detecting at least portion of the obstructive object projected in the one or more images, and processing the one or more images with the projected obstructive object to assist an operation of the movable object.

What is claimed is: 
     
         1 . A method for controlling a movable object, comprising:
 acquiring one or more images captured by an imaging device borne by the movable object, wherein the imaging device is at least partially blocked by an obstructive object attached to the movable object;   detecting at least portion of the obstructive object projected in the one or more images; and   processing the one or more images with the projected obstructive object to assist an operation of the movable object.   
     
     
         2 . The method of  claim 1 , wherein the obstructive object includes at least a portion of a blade of a propeller system for providing a motion of the movable object. 
     
     
         3 . The method of  claim 2 , wherein the blade comprises a plurality of reflective stripes distributed on a lower surface of the blade facing the imaging device. 
     
     
         4 . The method of  claim 1 , further comprising:
 applying a template to the one or more images to obtain one or more projected locations of the obstructive object within the one or more images.   
     
     
         5 . The method of  claim 4 , wherein the template includes one or more lines respectively representing the one or more projected locations of the obstructive object during a rotational motion, wherein each of the one or more lines is associated with a rotation angle of a corresponding one of the one or more projected locations. 
     
     
         6 . The method of  claim 5 , wherein:
 the obstructive object includes at least a portion of a blade of a propeller system for providing a motion of the movable object, and the blade includes a plurality of reflective stripes distributed on a lower surface of the blade facing the imaging device; and   the template comprises a first group of markers distributed on the one or more lines, and a second group of markers distributed on motion trails of the reflective stripes of the blade during the rotational motion.   
     
     
         7 . The method of  claim 6 , wherein detecting the at least portion of the obstructive object projected in the one or more images comprises:
 collecting pixels in one of the one or more images corresponding to the first group of markers and the second group of markers in the template;   determining whether pixel values of the collected pixels corresponding to each line of the one or more lines satisfy predetermined criteria;   in accordance with a determination that the pixel values of the collected pixels corresponding to one of the one or more lines satisfy the predetermined criteria, identifying that the obstructive object exists at a rotation angle associated with the one of the one or more lines in the one of the one or more images.   
     
     
         8 . The method of  claim 1 , wherein processing the one or more images with the projected obstructive object to assist the operation of the movable object comprises eliminating at least portion of the obstructive object projected in the one or more images. 
     
     
         9 . The method of  claim 8 , further comprising:
 identifying an exposure type of the one or more images.   
     
     
         10 . The method of  claim 9 , further comprising:
 in accordance with a determination that one of the one or more images is a short-exposure image, eliminating pixels in the one of the one or more images corresponding to the obstructive object at one or more detected locations.   
     
     
         11 . The method of  claim 9 , further comprising:
 in accordance with a determination that one of the one or more images is a long-exposure image, eliminating areas in the one of the one or more images corresponding to reflective stripes on a blade of a propeller system at one or more detected locations.   
     
     
         12 . A system for controlling a movable object, the system comprising:
 one or more processors coupled to the imaging device; and   a memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for:
 acquiring one or more images captured by an imaging device borne by the movable object, wherein the imaging device is at least partially blocked by an obstructive object attached to the movable object; 
 detecting at least portion of the obstructive object projected in the one or more images; and 
 processing the one or more images with the projected obstructive object to assist an operation of the movable object. 
   
     
     
         13 . The system of  claim 12 , wherein the obstructive object includes at least a portion of a blade of a propeller system for providing a motion of the movable object. 
     
     
         14 . The system of  claim 12 , wherein the one or more programs further include instructions for:
 applying a template to the one or more images to obtain one or more projected locations of the obstructive object within the one or more images.   
     
     
         15 . The system of  claim 14 , wherein the template includes one or more lines respectively representing the one or more projected locations of the obstructive object during a rotational motion, wherein each of the one or more lines is associated with a rotation angle of a corresponding one of the one or more projected locations. 
     
     
         16 . The system of  claim 15 , wherein the template comprises a first group of markers distributed on the one or more lines, and a second group of markers distributed on motion trails of a plurality of reflective stripes of a blade of a propeller system during the rotational motion. 
     
     
         17 . The system of  claim 12 , wherein the one or more programs further include instructions for:
 identifying an exposure type of the one or more images.   
     
     
         18 . The system of  claim 17 , wherein the one or more programs further include instructions for:
 in accordance with a determination that one of the one or more images is a short-exposure image, eliminating pixels in the one of the one or more images corresponding to the obstructive object at one or more detected locations.   
     
     
         19 . The system of  claim 17 , wherein the one or more programs further include instructions for:
 in accordance with a determination that one of the one or more images is a long-exposure image, eliminating areas in the one of the one or more images corresponding to reflective stripes on a blade of a propeller system at one or more detected locations.   
     
     
         20 . An unmanned aerial vehicle (UAV), comprising:
 a propulsion system;   one or more sensors;   an imaging device comprising an image sensor and an optical device; and   one or more processors coupled to the propulsion system, the one or more sensors, and the imaging device, the one or more processors being configured to:
 acquire one or more images captured by the imaging device borne by the UAV, wherein the imaging device is at least partially blocked by an obstructive object attached to the UAV; 
 detect at least portion of the obstructive object projected in the one or more images; and 
 process the one or more images with the projected obstructive object to assist an operation of the UAV.