SYSTEM AND METHOD FOR IMAGE IMPROVED IMAGE ENHANCEMENT

• US 20140029850A1
• Filed: 09/09/2013
• Published: 01/30/2014
• Est. Priority Date: 09/28/2011
• Status: Active Grant

• Current Assignee: The United States Of America As Represented By The Secretary Of The Army
• Original Assignee: US Army Research Laboratory (Government of the United States of America)
• Inventors: Meyers, Ronald E., Deacon, Keith S.
• Granted Patent: US 8,948,539 B2
• Time in Patent Office: Days
• US Class Current: 382/167
• CPC Class Codes: G06T 2207/20216 Image averaging
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06V 10/30 Noise filtering

Abstract

System and method for image improvement comprising providing a series of frames; summing pixel values to obtain frame intensity; computing average frame intensity; determining frame intensity deviation for each frame by subtracting average frame intensity from frame intensity; determining an array of average pixel values (AAPV) and subtracting AAPV from the pixel value arrays to determine positive or negative pixel deviation values; grouping frames in first or second groups depending positive or negative frame intensity deviation; selecting all pixel values having a positive or negative deviation value and creating subgroups of positive or negative pixel deviation value frames, multiplying the pixel deviation value frames in each subgroup by frame intensity deviation to create first product arrays, which are summed together and divided by total number of frames to obtain second product arrays for each subgroup; selecting one or more of second product arrays to generate an image.

Claims

1. A processor-implemented method for image improvement comprising the following steps not necessarily in sequential order:

providing a series of frames;

determining the value of each pixel at each location within each frame to form a pixel value array for each frame;

summing the pixel values in each frame to obtain the frame intensity for each frame;

computing the average frame intensity for the series of frames;

determining the frame intensity deviation for each frame by subtracting the average frame intensity for the series of frames from the frame intensity for each frame;

determining an array of average pixel values for the series of frames;

determining the deviations from the array of average pixel values for each pixel in each frame by subtracting the array of average pixel values from the pixel value arrays to determine positive or negative pixel deviation values;

grouping all frames in a first group that have a positive frame intensity deviation;

for all frames in the first group, selecting all pixel values in each frame having a positive deviation value and creating a first subgroup of positive pixel deviation value frames;

for all frames in the first group, selecting all pixel deviation values in each frame having a negative deviation value and creating a second subgroup of negative pixel deviation value frames;

grouping all frames in a second group that have a negative frame intensity deviation;

for all frames in the second group, selecting all pixel values in each frame having a positive deviation value and creating a third subgroup of positive pixel deviation value frames;

for all frames in the second group, selecting all pixel deviation values in each frame having a negative value and creating a fourth subgroup of negative pixel deviation value frames;

multiplying the pixel deviation value frames in each subgroup by the frame intensity deviation for the respective frame to create first product arrays;

summing the first product arrays together and dividing by the total number of frames to obtain a second product array for each sub group;

selecting one or more of the second product arrays to generate an enhanced image.

2. The method of claim 1 wherein the pixel values having a zero deviation value (Δ

I₁) are grouped in either the first subgroup of positive pixel deviation value frames or the second subgroup of negative pixel deviation value frames or to both subgroups or omitted.

3. The method of claim 1 wherein if the deviation of the sums of pixel group, to both groups, or to neither group;

4. The method of claim 1 wherein all second product arrays are combined after reversing the sign of the negative valued second product arrays to generate an enhanced image.

5. The method of claim 1 wherein all second product arrays are combined to generate an enhanced image.

6. The method of claim 1 wherein the frames inputted were influenced by the effects of low-light.

7. The method of claim 1 wherein the frames comprise images of an emitting target.

8. The method of claim 1 wherein the frames are in color.

9. The method of claim 1 wherein the frames inputted were influenced by the effects of turbulence or were taken in bad or changing weather.

10. The method of claim 1 wherein average frame intensity can be represented by <

I₁>

;

computing the average frame intensity for the series of frames can be represented by <

I₂>

;

determining the frame intensity deviation can be represented by Δ

I₂=I₂−

<

I₂>

;

determining an array of average pixel values for the series of frames;

can be represented by <

I₁>

;

determining the deviations from the array of average pixel values for each pixel in each frame by subtracting the array of average pixel values from the pixel value arrays to determine positive or negative pixel deviation values can be represented by Δ

I₁=I₁−

<

I₁>

; and

wherein the enhanced image can be represented as <

Δ

I₁Δ

I₂>

=<

I₁I₂>

−

<

I₁>

<

I₂>

.

11. The method of claim 1 wherein the step of summing the pixel values in each frame to obtain the frame intensity for each frame comprises adding together the values for the pixels in each frame using a digital camera.

12. The method of claim 1 wherein the step of determining the frame intensity of each frame comprises illuminating a target and determining the amount of light reflected from the target by detecting the reflected illumination using at least one detector.

13. The method of claim 12 wherein the at least one detector is one of a camera, bucket detector or charge coupled device.

14. A system for image improvement comprising

at least one processor,

at least one memory operatively associated with the at least one processor adapted to store frames of data taken of a region of interest, each frame of data comprising an array of pixels, each pixel having a pixel value, each frame having a frame intensity correlating to the sum of the pixel values for each frame;

the at least one processor operating to

compute the average frame intensity for the series of frames;

determine the frame intensity deviation for each frame by subtracting the average frame intensity for the series of frames from the frame intensity for each frame;

determine an array of average pixel values for the series of frames;

determine the deviations from the array of average pixel values for each pixel in each frame by subtracting the array of average pixel values from the pixel value arrays to determine positive or negative pixel deviation values;

group all frames in a first group that have a positive frame intensity deviation,

for all frames in the first group, select all pixel values in each frame having a positive deviation value and create a first subgroup of positive pixel deviation value frames,

for all frames in the first group, select all pixel deviation values in each frame having a negative value and create second subgroup of negative pixel deviation value frames;

group all frames in a second group that have a negative frame intensity deviation,

for all frames in the second group, select all pixel values in each frame having a positive deviation value and create a third subgroup of positive pixel deviation value frames,

for all frames in the second group, select all pixel deviation values in each frame having a negative value and create a fourth subgroup of negative pixel deviation value frames,

multiply the pixel deviation value frames in each subgroup by the frame intensity deviation for the respective frame to create first product arrays;

sum the first product arrays together and dividing by the total number of frames to obtain an second product arrays for each sub group;

select one or more of the second product arrays to generate an enhanced image.

15. The system of claim 14 further comprising at least one input for inputting a series of frames taken of a region of interest and wherein the frames of data are pictures taken of the region of interest during turbulent conditions.

16. The system of claim 14 further comprising a detector operatively associated with the at least one processor operating to determine the light intensity for each frame.

17. The system of claim 14 wherein the frame intensity is determined by summing the values for the pixels in each frame using a digital camera.

18. The system of claim 14 wherein the frames of data may be represented by I(x, y, t_i), and wherein the frames are averaged to generate an averaged first-order image of the subject <

I(x, y, t_i)>

where <

>

indicates an ensemble average, and wherein the enhanced images is a second order image that involves averages of products of two first-order intensity or normalized intensity measurements and wherein an enhanced image results from the subtraction of products of averages of first order intensities from the average of the product of the intensities.

19. A method for image improvement of low-light or radiation emitting areas comprising:

at least one processor,

at least one memory operatively associated with the at least one processor,

the at least one processor operating to perform the following steps not necessarily in sequential order;

providing a series of frames of a given region of interest;

determining the value of each pixel at each location within each frame to form a first array of pixel values for each frame;

determining the overall intensity of each frame;

determining the product of the overall intensity and the array of pixel values for each frame;

determining the sum of the products by adding together the products of the overall frame intensity and first array of pixel values for each frame;

determining the average of the sum of products by dividing the sum of products by the number of frames in the series of frames;

determining the average value of each pixel at each pixel location for the series of frames to form a second array of average pixel values;

determining the average overall frame intensity for the series of frames;

determining a second product of the second array of average pixel values and the average overall frame intensity;

subtracting the second product from the first product to provide an improved image of the region of interest.

20. The method of claim 19 further comprising the steps of

partitioning the improved image into at least two partitions based on a predetermined criteria;

mathematically operating upon the partitioned improved image to increase image contrast or image clarity.