Method for depth detection in 3D imaging providing a depth measurement for each unitary group of pixels

• US 6,856,407 B2
• Filed: 04/19/2001
• Issued: 02/15/2005
• Est. Priority Date: 09/13/2000
• Status: Expired due to Fees

• Current Assignee: NextPat Limited
• Original Assignee: NextEngine, Inc.
• Inventors: Agabra, David S., McKinley, William D., Knighton, Mark S.
• Primary Examiner(s): Rosenberger, Richard A.
• Application Number:
  US09/839,755
• Publication Number:
  US 20020033955A1
• Time in Patent Office: 1,398 Days
• Field of Search: 356/601, 356/602, 356/603, 356/610
• US Class Current: 356/601
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light

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.

Claims

1. A method comprising:

capturing an intensity at a location on a surface in a single pixel of an image sensing array (ISA);

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; and

comparing a plurality of captures of the intensity at the location under different conditions to compensate for non-homogeneous environments or surfaces.

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. A method comprising:

capturing an intensity at a location on a surface in a single pixel of an image sensing array (ISA);

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; and

comparing a plurality of captures of the intensity at the location at different points in time to compensate for non-homogeneous environments or surfaces.

5. 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;

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; and

comparing a plurality of captures of the intensity at the location at different points in time to compensate for non-homogeneous environments or surfaces.

6. The method of claim 5 wherein the ISA is a linear image sensor.

7. The method of claim 6 wherein the linear image sensor is one of a linear charge coupled device (CCD) and a photo diode array.

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;

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; and

comparing a plurality of captures of the intensity at the location under different conditions to compensate for non-homogeneous environments of surfaces.

9. A method comprising:

capturing a spectral energy distribution returned from a location on a surface in a single pixel of an ISA;

converting the spectral energy distribution into a measurement of distance 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; and

comparing a plurality of captures of the spectral energy distribution at the location at different points in time to compensate for non-homogeneous environments or surfaces.

10. 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;

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; and

comparing a plurality of captures of the electrical signal at the single pixel corresponding to the location on the surface at different points in time to compensate for non-homogeneous environments or surfaces.

11. 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 an elementary group of pixels on the ISA without regard to variations in electrical signals within the group responsive to the alteration;

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 elementary group of pixels; and

comparing a plurality of captures of the electrical signal at the elementary group of pixels corresponding to the location on the surface under different conditions to compensate for non-homogeneous environments or surfaces.

12. A method comprising:

capturing an intensity at a location on a surface in a single pixel of a linear image sensing array (ISA);

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; and

comparing a plurality of captures of the intensity at the location under different conditions to compensate for non-homogeneous environments or surfaces.