Systems and methods for processing infrared images

• US 8,780,208 B2
• Filed: 06/21/2012
• Issued: 07/15/2014
• Est. Priority Date: 03/02/2009
• Status: Active Grant

• Current Assignee: Teledyne FLIR LLC (Teledyne Technologies Incorporated)
• Original Assignee: FLIR Systems, Inc. (Teledyne Technologies Incorporated)
• Inventors: Hgasten, Nicholas, Ingerhed, Malin
• Primary Examiner(s): Donaghue, Larry
• Assistant Examiner(s): MCLEOD, MARSHALL M
• Application Number:
  US13/529,772
• Publication Number:
  US 20120321212A1
• Time in Patent Office: 754 Days
• Field of Search: 348/164
• US Class Current: 348/164
• CPC Class Codes: H04N 25/677 for reducing the column or line fixed pattern noise
• 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

One or more embodiments of the invention provide a system and method for processing an infrared image to receive infrared image data of a non-uniform scene, apply column noise filter correction to the infrared image data, and/or apply row noise filter correction to the infrared image data, and provide corrected infrared image data based on the column and/or row noise filter correction as infrared output image data.

Claims

1. A method of processing infrared image data, the method comprising:

receiving infrared image data from an infrared detector based on a non-uniform scene, wherein the infrared image data comprises pixels arranged in a plurality of rows and columns;

for each pixel of at least a portion of each column, determining differences between the pixel and a plurality of other pixels in a neighborhood that includes the pixel;

for each pixel of the portion of each column, determining a mean difference based on at least a subset of the differences between the pixel and the other pixels;

determining a corresponding column correction term for each column based on at least the mean differences determined for the pixels of the column; and

applying the column correction terms to the infrared image data to provide corrected infrared image data with reduced spatial noise.

2. The method of claim 1, wherein the determining the mean difference comprises estimating the differences between the pixel and the other pixels using a recursive filter.

3. The method of claim 1, wherein the column correction terms are current column correction terms, the method further comprising applying previously determined column correction terms to the image data before determining the current column correction terms.

4. The method of claim 1, further comprising high pass filtering the infrared image data before determining the column correction terms.

5. The method of claim 1, wherein the neighborhood is a subset of one of the rows.

6. The method of claim 1, wherein the neighborhood is a subset of the column.

7. The method of claim 1, wherein the subset comprises any of the differences less than a threshold, the method further comprising ignoring any of the differences that exceed the threshold.

8. The method of claim 1, further comprising:

for each pixel of at least a portion of each row, determining differences between the pixel of the row and a plurality of other pixels in another neighborhood that includes the pixel of the row;

determining a corresponding row correction term for each row based on at least a subset of the differences of the pixels of the row; and

applying the row correction terms to the infrared image data to provide corrected infrared image data with further reduced spatial noise.

9. A non-transitory computer readable medium on which are stored computer readable instructions to perform the method of claim 1.

10. A system comprising:

a memory component adapted to receive infrared image data based on a non-uniform scene, wherein the infrared image data comprises pixels arranged in a plurality of rows and columns; and

a processor adapted to execute instructions to;

for each pixel of at least a portion of each column, determine differences between the pixel and a plurality of other pixels in a neighborhood that includes the pixel,

for each pixel of the portion of each column, determine a mean difference based on at least a subset of the differences between the pixel and the other pixels,

determine a corresponding column correction term for each column based on at least the mean differences determined for the pixels of the column, and

apply the column correction terms to the infrared image data to provide corrected infrared image data with reduced spatial noise.

11. The system of claim 10, further comprising an infrared detector adapted to provide the infrared image data.

12. The system of claim 10, wherein the processor is adapted to execute instructions to estimate the differences between the pixel and the other pixels using a recursive filter to determine the mean difference.

13. The system of claim 10, wherein:

the column correction terms are current column correction terms; and

the processor is adapted to execute instructions to apply previously determined column correction terms to the image data before the current column correction terms are determined.

14. The system of claim 10, wherein the processor is adapted to execute instructions to high pass filter the infrared image data before the column correction terms are determined.

15. The system of claim 10, wherein the neighborhood is a subset of one of the rows.

16. The system of claim 10, wherein the neighborhood is a subset of the column.

17. The system of claim 10, wherein:

the subset comprises any of the differences less than a threshold; and

the processor is adapted to execute instructions to ignore any of the differences that exceed the threshold.

18. The system of claim 10, wherein the processor is adapted to execute instructions to:

for each pixel of at least a portion of each row, determine differences between the pixel of the row and a plurality of other pixels in another neighborhood that includes the pixel of the row;

determine a corresponding row correction term for each row based on at least a subset of the differences of the pixels of the row; and

apply the row correction terms to the infrared image data to provide corrected infrared image data with further reduced spatial noise.