IMAGE STABILIZATION SYSTEMS AND METHODS

• US 20130169819A1
• Filed: 12/27/2012
• Published: 07/04/2013
• Est. Priority Date: 12/30/2011
• Status: Active Grant

• Current Assignee: Flir Systems AB (Teledyne Technologies Incorporated)
• Original Assignee: Flir Systems AB (Teledyne Technologies Incorporated)
• Inventors: Strandemar, Katrin
• Granted Patent: US 9,338,352 B2
• Time in Patent Office: Days
• US Class Current: 348/164
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A method and systems of stabilizing a sequence of infrared (IR) images captured using an infrared (IR) imaging system, includes: generating edge information representations of selected captured IR images in said sequence; for each generated edge information representation, generating a second representation having a reduced amount of information compared to the edge information representation; determining displacements between captured IR images in relation to previous IR images in said sequence based on a comparison between said second representations; generating a stabilized sequence of IR images by shifting said captured IR images based on said determined displacements.

Claims

1. A method of stabilizing a sequence of infrared (IR) images captured using an infrared (IR) imaging system, the method comprising:

generating edge information representations of selected captured IR images in said sequence;

for each generated edge information representation, generating a second representation having a reduced amount of information compared to the edge information representation;

determining displacements between captured IR images in relation to previous IR images in said sequence based on a comparison between said second representations of IR images; and

generating a stabilized sequence of IR images by shifting said captured IR images based on said determined displacements.

2. The method of claim 1, further comprising:

for each of a first and a second IR image;

i) identifying pixels comprising edge information;

ii) generating an edge map, wherein the pixels identified as comprising edge information are assigned pixel values that differ from the pixel values of the remaining pixels;

i) generating a data collection representing the distribution of the first and/or second pixel values in the edge map;

thus resulting in a first data collection representing the distribution of the first and/or second pixel values in the first edge map, and a second data collection representing the distribution of the first and/or second pixel values in the second edge map;

comparing the first data collection to the second data collection;

determining the displacement between said first and second IR images based on the comparison between the first and second data collections; and

shifting the second IR image based on the determined displacement, thereby achieving stabilization of the second image to the first image.

3. The method of claim 1, further comprising a selection of:

pre-filtering the selected IR images in order to extract high frequency content before identifying pixels comprising edge information; and

pre-filtering the selected IR images in order to remove noise from the image.

4. The method of claim 2, wherein the generating an edge map further comprises applying one or more threshold values to the first and second IR images, respectively.

5. The method of claim 2, wherein

the data collection for each of the selected IR images comprises the distribution of the first and/or second pixel values in the first image along an x-axis of the image and a y-axis of the image, respectively.

6. The method of claim 1, wherein the data collections for each of the selected IR images are generated by applying Radon transformations to the edge information representations.

7. The method of claim 2, wherein comparing the first data collection to the second data collection comprises at least two comparisons, wherein, for each sequent comparison, the second data collection is shifted in relation to the first data collection or the first data collection is shifted in relation to the second data collection.

8. The method of claim 4, further comprising a feedback control loop adapted to optimize said one or more threshold values that are to be applied to the second IR image, in order to obtain an optimized number of, or an optimized amount of, pixels in the second IR image that will be identified as comprising edge information.

9. The method of claim 8, wherein said one or more threshold values are controlled such that the percentage of pixels in the second IR image that are identified as comprising edge information approaches a preset desired percentage value β

.

10. The method of claim 8, wherein said one or more threshold values are controlled based on the one or more threshold parameters applied on the first IR image and the percentage of pixels identified as comprising edge information in the first IR image.

16. A computer system having a processor being adapted to perform any of the steps or functions of claim 1.

17. A computer-readable medium on which is stored non-transitory information adapted to control a processor to perform any of the steps or functions of claim 1.

18. A computer program product comprising code portions adapted to control a processor to perform any of the steps or functions of claim 1.

19. A computer program product comprising configuration data adapted to configure a Field-programmable gate array (FPGA) to perform any of the steps or functions of claim 1.

11. An infrared (IR) imaging system, comprising:

an infrared sensor;

a processor adapted to process infrared image data from the infrared sensor depicting a scene, the processor being further adapted to;

receive a sequence of infrared (IR) images captured using an infrared (IR) imaging device;

generate edge information representations of selected captured IR images in said sequence;

for each generated edge information representation, generate a second representation having a reduced amount of information compared to the edge information representation;

determine displacements between captured IR images in relation to previous IR images in said sequence based on a comparison between said second representations of IR images; and

generate a stabilized sequence of IR images by shifting said captured IR images based on said determined displacements.

12. The infrared (IR) imaging system of claim 11, further comprising a selection of:

a display component adapted to display the stabilized sequence of IR images;

a memory component adapted to store image data representing the stabilized sequence of IR images; and

an output component adapted to output the stabilized sequence of IR images to a receiving unit.

13. The infrared (IR) imaging system of claim 11, wherein the processor is configurable using a hardware description language (HDL)

14. The infrared (IR) imaging system of claim 11, wherein the processor is a Field-programmable gate array (FPGA).

15. The infrared (IR) imaging system of claim 11, the processor further being adapted to perform any of the steps or functions of claim 2.