NON-UNIFORM CORRECTION ILLUMINATION PATTERN

• US 20140267866A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: SHORT, David B., SPEARS, Kurt E., SIEVERT, Otto K., SMITH, Kenneth K.
• Granted Patent: US 9,148,573 B2
• Time in Patent Office: Days
• US Class Current: 348/333.1
• CPC Class Codes: G03B 17/54 with projector
• CPC Class Codes: G03B 21/13 Projectors for producing special effects at the edges of picture, e.g. blurring
• CPC Class Codes: G03B 21/147 Optical correction of image distortions, e.g. keystone
• CPC Class Codes: G03B 27/68 Introducing or correcting distortion, e.g. in connection with oblique projection
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 25/671 for non-uniformity detection or correction
• CPC Class Codes: H04N 3/23 Distortion correction, e.g. for pincushion distortion correction, S-correction
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3182 Colour adjustment, e.g. white balance, shading or gamut white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

An example system in accordance with aspects of the present disclosure includes a controller and a camera communicatively coupled to the controller to capture an image of a work surface. A projector is also provided and is coupled to the controller to project an illumination pattern onto the work surface during image capture by the camera.

Claims

1. A projection capture system, comprising:

a controller;

a camera communicatively coupled to the controller to capture an image of an object on a work surface; and

a projector communicatively coupled to the controller to project a non-uniform correction illumination pattern onto the work surface during image capture of an object by the camera.

2. The projection capture system of claim 1, wherein the controller is to cause the camera to capture an image of a blank work surface during a calibration process and to determine the non-uniform correction illumination pattern based at least in part on the captured image of the blank work surface.

3. The projection capture system of claim 2, wherein the controller is further to determine the non-uniform correction illumination pattern by inverting the captured image of the blank work surface.

4. The projection capture system of claim 2, wherein the controller is further to determine the non-uniform correction illumination pattern by normalizing the captured image of the blank work surface to produce a normalized captured image and subtracting each pixel of the normalized captured image from 1.

5. The projection capture system of claim 2, wherein the controller is further to store the non-uniform correction illumination pattern in memory and subsequently to retrieve the non-uniform correction illumination pattern from memory for projection onto the work surface during image capture of the object.

6. The projection capture system of claim 2, wherein the controller repeatedly is to capture the image of the blank work surface and to store a digital representation of each non-uniform correction illumination pattern in memory.

7. The projection capture system of claim 1 wherein the projection capture system is to attach to at least one of an all-in-one computer and a display.

8. The projection capture system of claim 1 wherein the non-uniform correction illumination pattern comprises a plurality of output illumination pixels being set to an individually predetermined output intensity.

9. A projection capture system, comprising:

a controller;

a projector communicatively coupled to the controller; and

a camera communicatively coupled to the controller to capture an image of an object on a work surface;

wherein the controller is to perform a calibration cycle in which the controller is to determine that no object is present on a work surface, cause the camera to capture an image of the blank work surface using a uniform light source generated by the projector, and generate a non-uniform correction illumination pattern based at least in part on the captured image of the blank work surface.

10. The projection capture system of claim 9, wherein the controller is further to generate the non-uniform correction illumination pattern by inverting the captured image of the blank work surface.

11. The projection capture system of claim 9, wherein the controller is further to generate the non-uniform correction illumination pattern by normalizing the captured image of the blank work surface to produce a normalized captured image and inverting the normalized captured image.

12. The projection capture system of claim 11, wherein the controller is further to invert the normalized captured image by subtracting each pixel of the normalized captured image from a threshold value.

13. The projection capture system of claim 12, wherein the threshold value is 1.

14. The projection capture system of claim 9, further comprising an object recognition device to determine whether an object is present on the work surface.

15. The projection capture system of claim 14, wherein the controller is to perform the calibration process upon the object recognition device determining no object is present on the work surface.

16. The projection capture system of claim 9, wherein the projection capture system is to attach to at least one of an all-in-one computer and a display.

17. A method, comprising:

retrieving a non-uniform correction illumination pattern from a storage device;

projecting said non-uniform correction illumination pattern; and

capturing an image of an object while projecting said non-uniform correction illumination pattern.

18. The method of claim 17, further comprising generating the non-uniform correction illumination pattern by acquiring an image of a blank work surface using a uniform illumination pattern.

19. The method of claim 18, wherein generating the non-uniform correction illumination pattern comprises inverting the image of the blank work surface.

20. The method of claim 18, further comprising determining, using a camera, whether the work surface is blank and acquiring the image of the blank work surface using the uniform illumination pattern in response to determining that the work surface is blank.