Systems and methods for dewarping images

• US 10,249,022 B2
• Filed: 03/20/2018
• Issued: 04/02/2019
• Est. Priority Date: 08/19/2016
• Status: Active Grant

• Current Assignee: Intelligent Security Systems (ISS)
• Original Assignee: Intelligent Security Systems (ISS)
• Inventors: Stepanenko, Oleg Vladimirovich
• Primary Examiner(s): Liew, Alex Kok S
• Application Number:
  US15/926,001
• Publication Number:
  US 20180276792A1
• Time in Patent Office: 378 Days
• CPC Class Codes: B60R 2300/30 characterised by the type of image processing
• CPC Class Codes: B60R 2300/80 characterised by the intended use of the viewing arrangement
• CPC Class Codes: G06T 1/0007 Image acquisition
• CPC Class Codes: G06T 3/4007 based on interpolation, e.g. bilinear interpolation image demosaicing G06T3/4015; edge-driven or edge-based scaling G06T3/403
• CPC Class Codes: G06T 5/80 Geometric correction
• CPC Class Codes: H04N 23/661 Transmitting camera control signals through networks, e.g. control via the Internet
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 23/81 for suppressing or minimising disturbance in the image signal generation

Abstract

A computer-implemented method comprises: extracting a setting from a description file of a virtual pan-tilt-zoom (PTZ) camera used to capture an original image through a wide-angle lens; determining a first set of coordinates of a pixel of the original image for each cell of a sparse conversion map represented as a first look-up table, wherein the sparse conversion map corresponds to a sparse grid of pixels of an output image; determining, via interpolating the first set of coordinates, a second set of coordinates of a pixel of the original image for each cell of a full conversion map, wherein the second set of coordinates is represented as a second look-up table, wherein the full conversion map corresponds to a full grid of pixels of the output image; instructing a display to present the output image, wherein the original image is less rectilinear than the output image.

Claims

1. A device comprising:

a camera containing a processor, a memory, and a wide-angle lens, wherein the processor is coupled to the memory, wherein the memory stores a file and a set of instructions, wherein the file contains a setting, wherein the set of instructions executably configures the processor to;

access a first image captured via the wide-angle lens, wherein the first image includes a pixel;

read the setting;

determine a first set of coordinates of the pixel based on the setting and for each cell of a sparse conversion map;

interpolating the first set of coordinates to obtain a second set of coordinates, wherein the second set of coordinates is associated with a second image,

wherein the first image would be less rectilinear than the second image when the first image and the second image are displayed,

wherein the second image is associated with the sparse conversion map corresponding to a sparse grid of pixels, and

wherein the second image is associated with a full conversion map corresponding to a full grid of pixels with a plurality of cells; and

output the second image.

2. The device of claim 1, wherein the sparse conversion map is represented as a look-up table.

3. The device of claim 1, wherein the second set of coordinates is represented as a look-up table.

4. The device of claim 1, wherein the setting includes an identifier informative of a position of the wide-angle lens to be at least one of a ceiling position, a wall position, or a floor position.

5. The device of claim 1, wherein the setting includes a first angle value and a second angle value.

6. The device of claim 5, wherein the first angle value is a minimum angle value associated with the camera and the second angle value is a maximum angle value associated with the camera.

7. The device of claim 1, wherein the setting includes a resolution of the second image in pixels.

8. The device of claim 1, wherein the set of instructions further executably configures the processor to:

determine a distance to an image plane based on a zoom value and a normal vector of the image plane based on a pan value and a tilt value, wherein the setting includes at least one of the pan value or the tilt value, wherein the image plane in the file is based on the determining the distance and the normal vector, wherein the image plane is associated with at least one of the first image or the second image.

9. The device of claim 1, wherein determining the first set of coordinates comprises:

converting, by the processor, a coordinate associated with a cell of the sparse conversion map into a mathematical representation on an image plane; and

converting, by the processor, the mathematical representation into a set of 3D coordinates and then into a set of 2D coordinates, wherein the set of 3D coordinates and the set of 2D coordinates are from a coordinate system associated with the first image.

10. The device of claim 9, wherein determining the first set of coordinates further comprises:

converting, by the processor, the set of 2D coordinates associated with the first image into a set of pixel coordinates of the first image;

recording, by the processor, the set of pixel coordinates of the first image into the first look-up table.

11. The device of claim 1, wherein outputting further comprises:

requesting, by the processor, the second image to be sent to a server.

12. The device of claim 1, wherein outputting further comprises:

recording, by the processor, the second image onto the memory.

13. The device of claim 1, further comprising:

a platform supporting the camera, wherein the platform is configured such that a bottom of a vehicle is positioned before the camera when the vehicle drives over the platform.

14. The device of claim 13, wherein the set of instructions further executably configures the processor to access a third image captured via the wide-angle lens, wherein the first image, the second image, and the third image depict the bottom, wherein the second image and the third image are stitched to form a fourth image.

15. The device of claim 13, wherein the wide-lens is protected by a dome that is transparent.

16. The device of claim 13, wherein the platform supports a light source configured to operate with the camera.

17. The device of claim 16, wherein the camera and the light source are powered via a mains electricity source.

18. The device of claim 1, wherein the camera is a pantiltzoom (PTZ) camera.

19. The device of claim 18, wherein the camera is a virtual PTZ camera.

20. The device of claim 1, wherein the set of instructions further executably configures the processor to modify the second image other than dewarping before the outputting.