Methods for differential image quality enhancement for a multiple detector system, systems and use thereof

• US 9,471,969 B2
• Filed: 06/01/2015
• Issued: 10/18/2016
• Est. Priority Date: 06/23/2014
• Status: Active Grant

• Current Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation)
• Original Assignee: Exxonmobil Upstream Research Company (Exxon Mobil Corporation)
• Inventors: Zeng, Yousheng, Morris, Jonathan M., Abdelmoati, Hazem M.
• Primary Examiner(s): PATEL, KANJIBHAI B
• Application Number:
  US14/727,518
• Publication Number:
  US 20150371374A1
• Time in Patent Office: 505 Days
• Field of Search: 382/171, 382/274
• US Class Current: 1/1
• CPC Class Codes: G01M 3/38 by using light G01M3/02 takes precedence
• CPC Class Codes: G01N 2021/3513 Open path with an instrumental source
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 2201/06113 Coherent sources; lasers
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10048 Infrared image
• CPC Class Codes: G06T 5/40 using histogram techniques
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/90 Dynamic range modification of images or parts thereof
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G08B 21/12 responsive to undesired emission of substances, e.g. pollution alarms
• CPC Class Codes: H04N 1/6077 Colour balance, e.g. colour cast correction
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene

Abstract

Methods for differential image quality enhancement for a detection system including multiple electromagnetic radiation detectors which include obtaining an image from a chemical band electromagnetic radiation detector and an image from a reference band electromagnetic radiation detector. Each of the images includes a plurality of pixels, each pixel having an associated intensity value. One or more intensity values of a plurality of pixels from the reference band image are adjusted based on one or more intensity value parameters of the chemical band image.

Claims

1. A method for detecting at least one chemical species using a detection system including multiple electromagnetic radiation detectors, the method comprising:

obtaining a first image from a first electromagnetic radiation detector configured to detect emission or absorption of the at least one chemical species released into an environment, the image including a first plurality of pixels, each pixel having an associated intensity value;

obtaining a second image from a second electromagnetic radiation detector configured to provide a reference background, the image including a second plurality of pixels, each pixel having an associated intensity value;

adjusting one or more intensity values of the first plurality of pixels based on one or more intensity value parameters of the first image;

adjusting one or more intensity values of the second plurality of pixels based on the one or more intensity value parameters of the first image;

obtaining subsequent images from the first electromagnetic radiation detector and the second electromagnetic radiation detector;

adjusting pixels of the subsequent images from the first electromagnetic radiation detector based on the adjusted intensity values of the first plurality of pixels;

adjusting pixels of the subsequent images from the second electromagnetic radiation detector based on the adjusted intensity values of the second plurality of pixels; and

determining the presence or absence of a chemical species based, at least in part, on a comparison of the adjusted images from the first electromagnetic radiation detector and the second electromagnetic radiation detector, wherein the first plurality of pixels of the first image and the second plurality of pixels of the second image are substantially temporally and spatially aligned.

2. The method of claim 1, wherein adjusting the one or more intensity values of the second plurality of pixels includes adjusting the gain and offset.

3. The method of claim 1, wherein the one or more intensity value parameters of the first image includes a maximum intensity (I_max) and a minimum intensity (I_min).

4. The method of claim 1, wherein periodically the one or more intensity value parameters are updated using subsequent images from the first electromagnetic radiation detector.

5. The method of claim 1 further comprising:

generating a histogram using at least a portion of the intensity values of the first plurality of pixels of the first image and at least a portion of the intensity values of the second plurality of pixels of the second image;

adjusting the intensity values to offset either the second plurality of pixels to align with the intensity distribution of the first plurality of pixels or the first plurality of pixels to align with the intensity distribution of the second plurality of pixels,

wherein the adjusting the one or more intensity values of the second plurality of pixels based on the one or more intensity value parameters of the first image includes adjusting the gain of the second plurality of pixels and the one or more intensity value parameters of the first image includes a maximum intensity (I_max) and a minimum intensity (I_min).

6. The method of claim 5 further comprising:

identifying at least a first area of interest including one or more of the first plurality of pixels and the corresponding one or more of the second plurality of pixels that are substantially temporally and spatially aligned; and

adjusting the intensity values to offset either the second plurality of pixels within the first area of interest to align with the intensity distribution of the first plurality of pixels within the first area of interest or the first plurality of pixels within the first area of interest to align with the intensity distribution of the second plurality of pixels within the first area of interest,

wherein the adjusting the one or more intensity values of the second plurality of pixels based on the one or more intensity value parameters of the first image includes adjusting the gain of the second plurality of pixels within the first area of interest and the one or more intensity value parameters of the first image includes a maximum intensity (I_max) and a minimum intensity (I_min) within the first area of interest.

7. The method of claim 6, wherein the first area of interest consists of one or more pixels having intensity values within a defined range of intensity values.

8. The method of claim 6, wherein the pixels within the first area of interest are determined by:

identifying at least one of the first plurality of pixels and one or more adjacent pixels.

9. The method of claim 6, further comprising:

identifying a second area of interest including one or more other pixels of the first plurality of pixels and the corresponding one or more of the second plurality of pixels that are substantially temporally and spatially aligned; and

adjusting the intensity values to offset either the second plurality of pixels within the second area of interest to align with the intensity distribution of the first plurality of pixels within the second area of interest or the first plurality of pixels within the second area of interest to align with the intensity distribution of the second plurality of pixels within the second area of interest,

wherein the adjusting the one or more intensity values of the second plurality of pixels based on the one or more intensity value parameters of the first image includes adjusting the gain of the second plurality of pixels within the second area of interest and the one or more intensity value parameters of the first image includes a maximum intensity (I_max) and a minimum intensity (I_min) within the second area of interest.

10. The method claim 9, wherein the first area of interest and the second area of interest are at least a 10×

10 grid of pixels.

11. The method of claim 6, wherein the one or more of the first plurality of pixels within the first area of interest is determined by identifying a first pixel of the first plurality of pixels and one or more adjacent pixels.

12. The method of claim 11, wherein the first pixel is identified by determining the differences between the intensity values of the first plurality of pixels and the corresponding second plurality of pixels and applying a threshold value to the determined differences in intensity values, the first pixel is selected from the differential intensity values greater than the threshold value.

13. The method of claim 12, wherein the differences between intensity values of the first plurality of pixels and the corresponding second plurality of pixels is determined by calculating the ratio of the intensity values between each of the first plurality of pixels of the first image and the corresponding second plurality of pixels of the second image.

14. The method of claim 12, wherein the differences between intensity values of the first plurality of pixels and the corresponding second plurality of pixels is determined by subtracting the intensity values between each of the first plurality of pixels of the first image and the corresponding second plurality of pixels of the second image.

15. The method of claim 1, further comprising identifying one or more areas of interest, wherein the one or more areas of interest are determined by:

obtaining a first baseline image from the first electromagnetic radiation detector, the first baseline image including a plurality of pixels, each pixel having an associated intensity value;

obtaining a second baseline image from the second electromagnetic radiation detector, the second baseline image including a plurality of pixels, each pixel having an associated intensity value;

determining the difference in intensity values between each of the plurality of pixels of the first baseline image and the plurality of pixels of the second baseline image, each of the plurality of pixels of the first baseline image and the plurality of pixels of the second baseline image are substantially temporally and spatially aligned;

generating a first table of baseline information, the first table including the differences in intensity values between each of the substantially temporally and spatially aligned plurality of pixels of the first baseline image and the plurality of pixels of the second baseline image;

determining the difference in intensity values between each of the first plurality of pixels of the first image and the second plurality of pixels of the second image, each of the first plurality of pixels and the second plurality of pixels are substantially temporally and spatially aligned; and

applying the differences in intensity values of the first table to the difference in intensity values between each of the substantially temporally and spatially aligned first plurality of pixels and second plurality of pixels, the pixels proximate one another representing non-zero values are grouped to form the one or more areas of interest,

wherein the adjusting the intensity values of the first plurality of pixels and the second plurality of pixels occurs within each of the one or more areas of interest based on the one or more intensity value parameters of the first image for each of the one or more areas of interest.

16. The method of claim 15, wherein the one or more intensity value parameters of the first image includes a maximum intensity (I_max) and a minimum intensity (I_min).

17. The method of claim 15, further comprising:

obtaining a third baseline image from the first electromagnetic radiation detector, the third baseline image including a plurality of pixels, each pixel having an associated intensity value;

obtaining a fourth image from the second electromagnetic radiation detector, the fourth image including a plurality of pixels, each pixel having an associated intensity value;

determining the difference in intensity values between each of the plurality of pixels of the third baseline image and the plurality of pixels of the fourth baseline image, each of the plurality of pixels of the third baseline image and the plurality of pixels of the fourth baseline image are substantially temporally and spatially aligned;

determining a moving average of the differences in intensity values of the first baseline image, the second baseline image, the third baseline image, and the fourth baseline image for use as the baseline information;

determining the difference in intensity values between each of the first plurality of pixels of the first image and the second plurality of pixels of the second image, each of the first plurality of pixels and the second plurality of pixels are substantially temporally and spatially aligned;

applying the differences in intensity values of the moving average baseline information to the difference in intensity values between each of the first plurality of pixels and the second plurality of pixels, the pixels proximate one another representing non-zero values are grouped to form one or more areas of interest; and

adjusting one or more intensity values of the first plurality of pixels and the second plurality of pixels within each of the one or more areas of interest based on the one or more intensity value parameters of the first image for each of the one or more areas of interest.

18. The method of claim 15, wherein the difference in intensity values is calculated by subtracting the intensity values.

19. The method of claim 15, wherein the difference in intensity values is determined by calculating the ratio of the intensity values.

20. A system for detecting at least one chemical species comprising:

a lens;

a beam splitter;

a first electromagnetic radiation detector configured to detect emission or absorption of the at least one chemical species released into an environment;

a second electromagnetic radiation detector configured to provide a reference background; and

an analysis system including code within a processor, a non-transitory, computer-readable medium, or a combination thereof, the code configured to direct the processor to;

identify a first image from the first electromagnetic radiation detector, the first image including a first plurality of pixels, each pixel having an associated intensity value,

identify a second image from the second electromagnetic radiation detector, the second image including a second plurality of pixels, each pixel having an associated intensity value,

adjust one or more intensity values of the first plurality of pixels based on one or more intensity value parameters of the first image;

adjust one or more intensity values of the second plurality of pixels based on the one or more intensity value parameters of the first image;

obtain subsequent images from the first electromagnetic radiation detector and the second electromagnetic radiation detector;

adjust pixels of the subsequent images from the first electromagnetic radiation detector based on the adjusted intensity values of the first plurality of pixels;

adjust pixels of the subsequent images from the second electromagnetic radiation detector based on the adjusted intensity values of the second plurality of pixels; and

determine the presence or absence of a chemical species based, at least in part, on a comparison of the adjusted images from the first electromagnetic radiation detector and the second electromagnetic radiation detector, wherein the first plurality of pixels of the first image and the second plurality of pixels of the second image are substantially temporally and aligned.

21. The system of claim 20, wherein the analysis system automatically adjusts the one or more intensity values.

22. A method of detecting at least one chemical species comprising:

providing a detection system including a first electromagnetic radiation detector configured to detect emission or absorption of the at least one chemical species released into an environment and a second electromagnetic radiation detector configured to provide a reference background;

splitting an electromagnetic radiation beam into at least a first electromagnetic radiation beam and a second electromagnetic radiation beam;

receiving at least a portion of the first electromagnetic radiation beam by the first electromagnetic radiation detector;

receiving at least a portion of the second electromagnetic radiation beam by the second electromagnetic radiation detector;

generating a first image by the first electromagnetic radiation detector and a second image by the second electromagnetic radiation detector;

adjusting gain and/or offset of the first plurality of pixels using a maximum intensity (I_max) and a minimum intensity (I_min) of the first image;

adjusting gain and/or offset of the second plurality of pixels using the maximum intensity (I_max) and the minimum intensity (I_min) of the first image;

obtaining subsequent images from the first electromagnetic radiation detector and the second electromagnetic radiation detector;

adjusting pixels of the subsequent images from the first electromagnetic radiation detector based on the gain and/or offset of the first plurality of pixels;

adjusting pixels of the subsequent images from the second electromagnetic radiation detector based on the gain and/or offset of the second plurality of pixels; and

determining the presence of at least one chemical species based, at least in part, on a comparison of the adjusted images from the first electromagnetic radiation detector and the second electromagnetic radiation detector, wherein the first plurality of pixels of the first image and the second plurality of pixels of the second image are substantially temporally and spatially aligned.