Method for elementary depth detection in 3D imaging

Abstract

A method and apparatus for obtaining up to one depth measurement for each pixel. A image sensing array (ISA) captures a measurement of intensity on a surface. The intensity maps to depth. Accordingly, from a single pixel, or a group of pixels without regard to the intensity distribution among the pixels in the group, a depth measurement can be obtained independently of any and/or all data captured by other pixels in the array.

What is claimed is:  
     
         1 . A method comprising: 
 capturing an intensity at a location on a surface in a single pixel of an image sensing array (ISA); and    converting the intensity into a measurement of distance to the location relative to a reference point independently of data from other pixels of the ISA and independent of time of flight of light reflected from the location to the single pixel.    
     
     
         2 . The method of  claim 1  wherein the ISA is a linear image sensor.  
     
     
         3 . The method of  claim 2  wherein the linear image sensor is one of a linear charge coupled device (CCD) and a photo diode array.  
     
     
         4 . The method of  claim 1  further comprising: 
 occluding incoming light to the single pixel incrementally to generate an intensity gradient over the location.  
 
     
     
         5 . The method of  claim 1  wherein converting the intensity into a measurement of distance further comprises: 
 retrieving a distance value from a look up table based on a differential intensity value.  
 
     
     
         6 . The method of  claim 5 , wherein distance values in the look up table are generated during a calibration of the ISA.  
     
     
         7 . The method of  claim 1 , further comprising: 
 capturing the intensity at a predefined interval.    
     
     
         8 . A method comprising: 
 capturing an intensity at a location on a surface in an elementary group of pixels on an image sensing array (ISA) without regard to intensity distribution within the group; and    converting the intensity into a measurement of distance to the location independently of data from other pixels on the ISA and independently of time of flight of light reflected from the location to the elementary group of pixels.    
     
     
         9 . The method of  claim 8  wherein the ISA is a linear image sensor.  
     
     
         10 . The method of  claim 9  wherein the linear image sensor is one of a linear charge coupled device (CCD) and a photo diode array.  
     
     
         11 . The method of  claim 8  further comprising: 
 occluding incoming light to the elementary group of pixels incrementally to generate an intensity gradient over the location.  
 
     
     
         12 . The method of  claim 8  wherein converting the intensity into a measurement of distance further comprises: 
 retrieving a distance value from a look-up table based on a differential intensity value.  
 
     
     
         13 . The method of  claim 12 , wherein distance values in the look-up table are generated during a calibration of the ISA.  
     
     
         14 . The method of  claim 8 , further comprising: 
 capturing the intensity at a predefined interval.    
     
     
         15 . A method comprising: 
 capturing a spectral energy distribution returned from a location on a surface in a single pixel of an ISA; and    converting the spectral energy distribution into a measurement of distance to the location relative to a reference point independently of data from other pixels of the ISA and independent of time of flight of light reflected from the location to the single pixel.    
     
     
         16 . A method comprising: 
 altering one of a spatial and optical relationship between an image sensing array (ISA) and a surface;    observing a variation of an electrical signal at a single pixel on the ISA responsive to the alteration; and    converting the variation to a measure of distance to a location on the surface relative to a reference point, independently of data from other pixels of the ISA and independent of time of flight of light reflected from the location to the single pixel.    
     
     
         17 . A method comprising: 
 altering one of a spatial and optical relationship between an image sensing array (ISA) and a surface; and    observing a variation of an electrical signal at an elementary group of pixels on the ISA without regard to variations in electrical signals within the group responsive to the alteration.    
     
     
         18 . A method comprising: 
 capturing an intensity at a location on a surface in a single pixel of a linear image sensing array (ISA); and    converting the intensity into a measurement of distance to the location relative to a reference point independently of data from other pixels of the linear ISA.