Method and apparatus for scannerless range image capture using photographic film

• US 6,118,946 A
• Filed: 06/29/1999
• Issued: 09/12/2000
• Est. Priority Date: 06/29/1999
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Mathers, Timothy P., Ray, Lawrence A.
• Primary Examiner(s): Perkey, W. B.
• Application Number:
  US09/342,370
• Time in Patent Office: 441 Days
• Field of Search: 396/89, 396/155, 396/222, 396/311, 396/310, 396/315, 396/429, 382/106, 356/3
• US Class Current: 396/89
• CPC Class Codes: G01S 17/894 3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
• CPC Class Codes: G03B 15/03 Combinations of cameras with lighting apparatus; Flash units
• CPC Class Codes: G06T 7/33 using feature-based methods
• CPC Class Codes: G06T 7/586 from multiple light sources, e.g. photometric stereo

Abstract

A method for image capture and estimation of range information is provided which uses photographic film as the image capture mechanism. A plurality of identical images are captured on film yielding an image bundle wherein each image in the image bundle is captured with a different phase offset. Fiducial marks are placed on the photographic film between adjacent images in the image bundle. The image bundle is developed and the developed images are scanned. The images of the image bundle are then registered by aligning the fiducial marks. The distance from the image capture device to object(s) in the images of the image bundle can then be estimated using the different phase offsets for each image. The range at a pixel location is estimated by selecting the intensity of the pixel at that location of each image and performing a best fit of a sine wave of one period through the points. The phase of the resulting best fitted sine wave is then used to estimate the range to the object based upon the wave length of the illumination frequency.

Claims

1. A method for image capture and estimation of range information comprising the steps of:

(a) capturing with an image capture device a plurality of identical images on photographic film to create an image bundle;

(b) performing said capturing step with a different phase offset for each image in the image bundle;

(c) placing at least two fiducial marks on the photographic film between adjacent images in the image bundle;

(d) developing the image bundle;

(e) scanning the image bundle;

(f) registering the images of the image bundle by aligning the fiducial marks; and

(g) estimating the distance from the image capture device to object(s) in the image bundle using the different phase offsets for each image.

3. A method as recited in claim 1 wherein:

said image bundle comprises at least three of said identical images.

4. A method as recited in claim 1 wherein:

said performing step comprises controlling a modulation frequency of a light source.

5. A method as recited in claim 4 further comprising the step of:

controlling a modulation frequency of an image intensifier.

6. A method as recited in claim 1 wherein:

said placing step is performed by writing a pattern on the photographic film between adjacent ones of the plurality of identical images using a camera data-back.

2. A camera system for capturing image bundles for use with a range imaging system, each image bundle including at three images, said camera comprising:

(a) a illumination source which is modulatable at frequencies in the range of from about 5 to about 50 mHz;

(b) a modulation controller for controlling the modulation frequency of said light source and of an image intensifier;

(c) a lens, light from said illumination source reflecting back from a scene to be captured as an image through said lens and said image intensifier;

(d) a phosphor screen positioned behind said image intensifier;

(e) a strip of photographic film containing a plurality of frames, said strip of photographic film contained with the camera system positioned behind said phosphor screen;

(f) a film advance mechanism for advancing said strip of photographic film; and

(g) a camera data-back for writing a pattern on said strip of photographic film between adjacent ones of said frames.