Scene-based non-uniformity correction in focal plane arrays

Patent metadata

Field	Value
Publication number	US-2016321789-A1
Application number	US-201515108602-A
Country	US
Kind code	A1
Filing date	Oct 20, 2015
Priority date	Oct 20, 2014
Publication date	Nov 3, 2016
Grant date	—

Abstract

Methods and systems for correcting non-uniformity in focal plane arrays include averaging pixel intensity values from a plurality of data captures to generate an image, spatially median filtering the image to generate a median filtered image, temporally stacking the median filtered image with at least one previously median filtered images to generate a median filtered image stack, and temporally median filtering a pixel offset value stack corresponding to each of a plurality of filtered pixel locations within the median filtered image stack to generate a process dataset.

First claim

What is claimed is:

1 . A method for correcting non-uniformity in focal plane arrays comprising the steps of:
receiving, at a computing device, a plurality of data captures from an image sensor, each of the plurality of data captures including a plurality of pixel intensity values, each of the plurality of pixel intensity values of each data capture corresponding to one of a plurality of pixel locations; averaging, by a processing component of the computing device, for each respective one of the pixel locations, at least two of the pixel intensity values to generate an image, each of the at least two of the pixel intensity values corresponding to a different one of the data captures and corresponding to a common one of the pixel locations; spatially median filtering, by the processing component of the computing device, the image to generate a median filtered image, the median filtered image including a plurality of spatially filtered pixel intensity values, each of the plurality of spatially filtered pixel intensity values corresponding to one of a plurality of filtered pixel locations and representative of a pixel offset value corresponding to the corresponding one of the filtered pixel locations; temporally stacking the median filtered image with at least one previously median filtered image stored in a memory component of the computing device to generate a median filtered image stack including a plurality of pixel offset value stacks, each of the pixel offset value stacks corresponding to one of the filtered pixel locations and including at least two stacked pixel offset values, each of the at least two stacked pixel offset values corresponding to a different one of the median filtered image or the at least one previously median filtered image and corresponding to a common one of the filtered pixel locations; and temporally median filtering, by the processing component of the computing device, each of the plurality of pixel offset value stacks of the median filtered image stack to generate a process dataset.

2 . The method of claim 1 , further comprising the steps of:
storing the process dataset in an offset file resident in the memory component of the computing device; and averaging the process dataset with at least one previously generated process dataset stored in the offset file.

3 . The method of claim 2 , wherein the step of averaging is performed using a weighted average.

4 . The method of claim 1 , wherein the computing device is a field-programmable gate array.

5 . The method of claim 1 , wherein the processing component of the computing device is a microprocessor.

6 . The method of claim 1 , wherein the image sensor and the computing device are installed on a common mobile host platform.

7 . The method of claim 1 , wherein the image sensor is installed on a mobile host platform and the computing device is installed on at least one of an additional mobile host platform or a fixed host platform.

8 . A system for correcting non-uniformity in focal plane arrays comprising:
an image sensor configured to capture image data; and a computing device in electronic communication with the image sensor and having a memory component and a processing component, the memory component including instructions that, when executed by the processing component, cause the computing device to:
receive a plurality of data captures from the image sensor, each of the plurality of data captures including a plurality of pixel intensity values, each of the plurality of pixel intensity values of each data capture corresponding to one of a plurality of pixel locations;
average, for each respective one of the pixel locations, at least two of the pixel intensity values to generate an image, each of the at least two of the pixel intensity values corresponding to a different one of the data captures and corresponding to a common one of the pixel locations;
spatially median filter the image to generate a median filtered image, the median filtered image including a plurality of spatially filtered pixel intensity values, each of the plurality of spatially filtered pixel intensity values corresponding to one of a plurality of filtered pixel locations and representative of a pixel offset value corresponding to the corresponding one of the filtered pixel locations;
temporally stack the median filtered image with at least one previously median filtered image stored in the memory component of the computing device to generate a median filtered image stack including a plurality of pixel offset value stacks, each of the pixel offset value stacks corresponding to one of the filtered pixel locations and including at least two stacked pixel offset values, each of the at least two stacked pixel offset values corresponding to a different one of the median filtered image or the at least one previously median filtered image and corresponding to a common one of the filtered pixel locations; and
temporally median filter each of the plurality of pixel offset value stacks of the median filtered image stack to generate a process dataset.

9 . The system of claim 8 , the memory component further including instructions that, when executed by the processing component, cause the computing device to:
store the process dataset in an offset file resident in the memory component of the computing device; and average the process dataset with at least one previously generated process dataset stored in the offset file.

10 . The system of claim 9 , wherein the average is determined using a weighted average.

11 . The system of claim 8 , wherein the computing device is at least one of a field-programmable gate array or a microprocessor.

12 . The system of claim 8 , wherein the image sensor and the computing device are installed on a common mobile host platform.

13 . The system of claim 8 , wherein the image sensor is installed on a mobile host platform and the computing device is installed on at least one of an additional mobile host platform or a fixed host platform.

14 . The system of claim 8 , wherein:
the image sensor is one of a plurality of image sensors installed on a common host platform, each of the image sensors configured to capture image data; and the computing device is one of a plurality of dedicated computing devices installed on the common host platform, each of the dedicated computing devices in electronic communication with a corresponding one of the image sensors and having a dedicated memory component and a dedicated processing component.

15 . A non-transitory computer-readable medium including instructions stored thereon that, when executed by a processing component, cause a computing device of a system for correcting non-uniformity in focal plane arrays to:
receive, at the computing device, a plurality of data captures from an image sensor, each of the plurality of data captures including a plurality of pixel intensity values, each of the plurality of pixel intensity values of each data capture corresponding to one of a plurality of pixel locations; average, by the processing component of the computing device, for each respective one of the pixel locations, at least two of the pixel intensity values to generate an image, each of the at least two of the pixel intensity values corresponding to a different one of the data captures and corresponding to a common one of the pixel locations; spatially median filter, by the processing component of the computing device, the image to generate a median filtered image, the median filtered image including a plurality of spatially filtered pixel intensity values, each of the pl

Assignees

• Bae Sys Inf & Elect Sys Integ

Inventors

• Mercier Michael N
• Cole Kevin C
• Schlupf Joseph M

Classifications

• H04N5/232

  Electricity · mapped topic

• G06T5/50 Primary

  using two or more images, e.g. averaging or subtraction · CPC title

• G06T5/20 Primary

  using local operators · CPC title

• G06T2207/10004

  Still image; Photographic image · CPC title

• G06T2207/20032

  Median filtering · CPC title