Color image rendering for ground-penetrating radar systems

1. A method for producing one or more images associated with a ground-penetrating radar (GPR), comprising:

receiving information representative of signals received by the GPR in response to transmission of radar signals and interaction thereof with one or more objects;

determining at least three frequency bands associated with the received information;

assigning a first color value to the received information corresponding to a first of the at least three frequency bands, a second color value to the received information corresponding to a second of the at least three frequency bands, and a third color value to the received information corresponding to a third of the at least three frequency bands;

generating a color image for the one or more objects by combining the received information in all of the at least three frequency bands together,

wherein color values in the color image indicate a size of the one or more objects, a depth at which the one or more objects is buried underground, or an electrical permittivity of the one or more objects.

2. The method of claim 1 , comprising:

generating a refined color image for the one or more objects by:

adjusting the at least three frequency bands associated with the received information based on the color image or a prior information about the one or more objects; and

refining the color image by assigning a fourth color value to the received information corresponding to a first of the adjusted frequency bands, a fifth color to the received information corresponding to a second of the adjusted frequency bands, and a sixth color to the received information corresponding to a third of the adjusted frequency bands.

3. The method of claim 2 , comprising:

determining a final color image by generating the refined color image iteratively.

4. The method of claim 1 , wherein the at least three frequency bands partially overlap with each other.

5. The method of claim 1 , wherein the at least three frequency bands have substantially similar widths.

6. The method of claim 1 , wherein the first color value, the second color value, and third color value are assigned according to an optical frequency order of color values corresponding to a frequency order of the at least three frequency bands such that a color value having a lower optical frequency is assigned to a lower frequency band.

7. The method of claim 1 , wherein the at least three frequency bands have different widths, and wherein a color value that has a lower optical frequency is assigned to a wider frequency band while a color value that has a higher optical frequency is assigned to a narrower frequency band.

8. The method of claim 1 , wherein the at least three frequency bands comprise four frequency bands, the method further comprising:

assigning a surface height value to the received information corresponding to a fourth of the four frequency bands such that the color image is three-dimensional.

9. The method of claim 1 , wherein the at least three frequency bands comprise four or more frequency bands, the method further comprising:

determining three frequency bands from the four or more frequency bands based on a prior information about the one or more objects or a ground in which the one or more objects are buried,

wherein each of the three frequency bands is selected from the four or more frequency bands or is determined by combining one or more of the four or more frequency bands.

10. The method of claim 1 , wherein the assigning of the first color value, the second color value, and the third color value comprises:

scaling a value representing the received information in one of the at least three frequency bands corresponding to an overall range of values for a color space of the first color value, the second color value, and the third color value.

11. The method of claim 1 , wherein the assigning of the first color value, the second color value, and the third color value comprises:

scaling a first value representing the received information in the first frequency band according to a range of the first color value;

scaling a second value representing the received information in the second frequency band according to a range of the second color value; and

scaling a third value representing the received information in the third frequency band according to a range of the third color value.

12. The method of claim 1 , wherein the assigning of the first color value, the second color value, and the third color value is non-linear such that an increment of a color value associated with a given increment of an intensity of a signal received by the GPR varies as the intensity of the signal increases.

13. The method of claim 1 , wherein the first color value, the second color value, and the third color value are values from a color space, the color space comprising a Red-Green-Blue (RGB) color space or a YCbCr color space.

14. A signal processing system for producing one or more images associated with a ground-penetrating radar (GPR), comprising:

a processor,

a memory with instructions stored thereon, wherein the instructions upon execution by the processor cause the processor to:

receive information representative of signals received by the GPR in response to transmission of radar signals and interaction thereof with one or more objects;

determine at least three frequency bands associated with the received information;

assign a first color value to the received information corresponding to a first of the at least three frequency bands, a second color value to the received information corresponding to a second of the at least three frequency bands, and a third color value to the received information corresponding to a third of the at least three frequency bands; and

generate a color image for the one or more objects by combining the received information in all of the at least three frequency bands together,

wherein color values in the color image indicate a size of the one or more objects, a depth at which the one or more objects is buried underground, or an electrical permittivity of the one or more objects.

15. The system of claim 14 , wherein the processor is configured to:

generate a refined color image for the one or more objects by:

adjusting the at least three frequency bands associated with the received information based on the color image or a prior information about the one or more objects; and

refining the color image by assigning a fourth color value to the received information corresponding to a first of the adjusted frequency bands, a fifth color to the received information corresponding to a second of the adjusted frequency bands, and a sixth color to the received information corresponding to a third of the adjusted frequency bands.

16. The system of claim 15 , wherein the processor is configured to:

determine a final color image by generating the refined color image iteratively.

17. The system of claim 14 , wherein each frequency band is partially overlapping with another frequency band.

18. The system of claim 14 , wherein the at least three frequency bands have substantially similar widths.

19. The system of claim 14 , wherein the first color value, the second color value, and third color value are assigned according to an optical frequency order of color values corresponding to a frequency order of the at least three frequency bands such that a color value having a lower optical frequency is assigned to a lower frequency band.

20. The system of claim 14 , wherein the at least three frequency bands have different widths, and wherein a color value that has a lower optical frequency is assigned to a wider frequency band while a color value that has a higher optical frequency is assigned to a narrower frequency band.

21. The system of claim 14 , wherein the at least three frequency bands comprise four frequency bands, and wherein the processor is configured to:

assign a surface height value to the received information corresponding to a fourth of the four frequency bands such that the color image is three-dimensional.

22. The system of claim 14 , wherein the at least three frequency bands four or more frequency bands, and wherein the processor is configured to:

determine three frequency bands from the four or more frequency bands based on a prior information about the one or more objects or a ground in which the one or more objects are buried,

wherein each of the three frequency bands is selected from the four or more frequency bands or is determined by combining one or more of the four or more frequency bands.

23. The system of claim 14 , wherein the processor is configured to assign the first color value, the second color value, and the third color value based on:

scaling a value representing the received information in one of the at least three frequency bands corresponding to an overall range of values for a color space of the first color value, the second color value, and the third color value.

24. The system of claim 14 , wherein the processor is configured to assign the first color value, the second color value, and the third color value based on:

scaling a first value representing the received information in the first frequency band according to a range of the first color value;

scaling a second value representing the received information in the second frequency band according to a range of the second color value; and

scaling a third value representing the received information in the third frequency band according to a range of the third color value.

25. The system of claim 14 , wherein the processor is configured to assign the first color value, the second color value, and the third color value is a non-linear manner such that an increment of a color value associated with a given increment of an intensity of a signal received by the GPR varies as the intensity of the signal increases.

26. The system of claim 14 , wherein the first color value, the second color value, and the third color value are values from a color space, the color space comprising a Red-Green-Blue (RGB) color space or a YCbCr color space.