초록 ▼

Methods and apparatus for digitally enhancing images are disclosed. In one embodiment, a method includes performing a wavelet transformation process on an acquired image to provide a low pass spatial frequency. A dynamic range and a mixing value are then determined from the low pass spatial frequenc

Methods and apparatus for digitally enhancing images are disclosed. In one embodiment, a method includes performing a wavelet transformation process on an acquired image to provide a low pass spatial frequency. A dynamic range and a mixing value are then determined from the low pass spatial frequency, and the mixing value is applied to provide a transformed output image. The transformed output image is then reformatted to provide a mixed output image, and the mixed output image is subtracted from the acquired image to provide an enhanced image. In an alternate embodiment, a method includes analyzing an acquired image to provide a high sensitive low light image and a low sensitive high light image, and then summing the high sensitive low light image and the low sensitive high light image to create an enhanced image.

대표청구항 ▼

What is claimed is: 1. A method of digitally enhancing an acquired image, comprising: performing at least one wavelet transformation process on the acquired image, the at least one wavelet transformation process providing at least one low pass spatial frequency; determining a dynamic range of at le

What is claimed is: 1. A method of digitally enhancing an acquired image, comprising: performing at least one wavelet transformation process on the acquired image, the at least one wavelet transformation process providing at least one low pass spatial frequency; determining a dynamic range of at least one low pass spatial frequency; determining at least one mixing value from the at least one low pass spatial frequency; applying the at least one mixing value to the at least one low pass spatial frequency to produce a transformed output image; reformatting the transformed output image to provide a mixed output image, wherein the reformatting the transformed images includes, for each wavelet transformation process performed on the acquired image: upscaling the transformed output image by two to provide a first upscaled image; calculating a horizontal high pass value from the first upscaled image; calculating a horizontal low pass value from the first upscaled image; translating the first upscaled image by �� pixel in a first orthogonal direction and by �� pixel in a second orthogonal direction; upscaling the first upscaled image by two to provide a second upscaled image; calculating a total high pass value from the second upscaled image; calculating a total low pass value from the upscaled decimated image; and translating the second upscaled image by �� pixel in the first orthogonal direction and by �� pixel in the second orthogonal direction; and subtracting the mixed output image from the acquired image to provide an enhanced image. 2. The method of claim 1, wherein performing at least one wavelet transformation on the acquired image includes performing at least one un-normalized wavelet transformation process on the acquired image. 3. The method of claim 1, wherein performing at least one wavelet transformation process on the acquired image includes: decimating the acquired image by two to provide a first decimated image; calculating a horizontal high pass value from the first decimated image; calculating a horizontal low pass value from the first decimated image; decimating the first decimated image by two to provide a second decimated image; calculating a total high pass value from the second decimated image; and calculating a total low pass value from the second decimated image. 4. The method of claim 1, wherein performing at least one wavelet transformation process on the acquired image includes performing a first un-normalized wavelet transformation process on the acquired image, the method further comprising performing a second un-normalized wavelet transformation process on a first decimated version of the acquired image, and performing a third un-normalized wavelet transformation process on a second decimated version of the acquired image. 5. The method of claim 1, further comprising: sharpening the acquired image, wherein the sharpening includes finding an edge intensity value and mixing the edge intensity value into the acquired image to provide a digitally-sharpened acquired image; and wherein subtracting the mixed output image from the acquired image includes subtracting the mixed output image from the digitally-sharpened acquired image to provide an enhanced image. 6. The method of claim 1, wherein determining a dynamic range of the at least one low pass spatial frequency includes: computing an over population of pixel intensities that are above an overflow value; and computing an under population of pixel intensities that are below an underfiow value. 7. The method of claim 6, wherein determining at least one mixing value from the at least one low pass spatial frequency includes determining at least one mixing value from the over and under populations. 8. The method of claim 6, wherein determining at least one mixing value from the at least one low pass spatial frequency includes determining a new mixing value from the over and under populations and an old mixing value. 9. The method of claim 1, wherein subtracting the mixed output image from the acquired image to provide an enhanced image includes scaling the mixed output image to allow direct subtraction of the mixed output image from the acquired image. 10. The method of claim 1, wherein applying the at least one mixing value to the at least one low pass spatial frequency to produce a transformed output image includes applying the at least one mixing value to remove at least one of an over saturation and an under saturation of the acquired image. 11. A method of digitally enhancing an acquired image, comprising: performing a first un-normalized wavelet transformation process on the acquired image to provide a first low pass spatial frequency; performing a second un-normalized wavelet transformation process on the first low pass spatial frequency to provide a second low pass spatial frequency; performing a third un-normalized wavelet transformation process on the second low pass spatial frequency to provide a third low pass spatial frequency; determining a dynamic range of each of the first, second, and third spatial frequencies; using the dynamic range of each spatial frequency, determining a mixing value for each low pass spatial frequency that removes at least one of an over saturation condition and an under saturation condition for each low pass spatial frequency; applying each respective mixing value to the corresponding first, second, and third low pass spatial frequencies to produce first, second, and third transformed output images, respectively; reformatting the first, second, and third transformed output images to provide first, second, and third mixed output images, respectively, wherein reformatting the transformed output images includes, for each wavelet transformation process performed on the acquired image: upscaling the transformed output image by a constant to provide a first upscaled image; calculating a horizontal high pass value from the first upscaled image; calculating a horizontal low pass value from the first upscaled image; translating the first upscaled image by a fraction of a pixel in a first orthogonal direction and by the fraction of a pixel in a second orthogonal direction; upscaling the first upscaled image by the constant to provide a second upscaled image; calculating a total high pass value from the second upscaled image; calculating a total low pass value from the upscaled decimated image; and translating the second upscaled image by the fraction of a pixel in the first orthogonal direction and by the fraction of a pixel in the second orthogonal direction; and subtracting the first, second, and third mixed output images from the acquired image to provide an enhanced image. 12. The method of claim 11, wherein at least one of the first, second, and third un-normalized wavelet transformation processes includes: decimating the acquired image by two to provide a first decimated image; calculating a horizontal high pass value from the first decimated image; calculating a horizontal low pass value from the first decimated image; decimating the first decimated image by two to provide a second decimated image; calculating a total high pass value from the second decimated image; and calculating a total low pass value from the second decimated image. 13. The method of claim 11, further comprising: sharpening the acquired image, wherein the sharpening includes finding an edge intensity value and mixing the edge intensity value into the acquired image to provide a digitally-sharpened acquired image; and wherein subtracting the first, second, and third mixed output images from the acquired image includes subtracting the first, second, and third mixed output image from the digitally-sharpened acquired image to provide an enhanced image. 14. The method of claim 11, wherein determining a dynamic range of each of the first, second, and third spatial frequencies includes, for each respective spatial frequency: computing an over population of pixel intensities that are above an overflow value; and computing an under population of pixel intensities that are below an underflow value. 15. The method of claim 11, wherein the constant includes a value of two, and wherein the fraction of a pixel includes �� pixel. 16. An apparatus for performing digitally-enhanced viewing operations, comprising: a camera configured to capture an acquired image; a display device; and a processing system operatively coupled between the camera and the display device, the processing system being configured to perform an image enhancement method to digitally enhance the acquired image to create a digitally enhanced image, and to output the digitally enhanced image to the display device, wherein the image enhancement method includes: performing at least one wavelet transformation process on the acquired image, the at least one wavelet transformation process providing at least one low pass spatial frequency; determining a dynamic range of the at least one low pass spatial frequency; determining at least one mixing value from the at least one low pass spatial frequency; applying the at least one mixing value to the at least one low pass spatial frequency to produce a transformed output image; reformatting the transformed output image to provide a mixed output image, wherein reformatting the transformed output images includes, for each wavelet transformation process performed on the acquired image: upscaling the transformed output image by two to provide a first upscaled image; calculating a horizontal high pass value from the first upscaled image; calculating a horizontal low pass value from the first upscaled image; translating the first upscaled image by �� pixel in a first orthogonal direction and by �� pixel in a second orthogonal direction; upscaling the first upscaled image by two to provide a second upscaled image; calculating a total high pass value from the second upscaled image; calculating a total low pass value from the upscaled decimated image; and translating the second upscaled image by �� pixel in the first orthogonal direction and by �� pixel in the second orthogonal direction; and subtracting the mixed output image from the acquired image to provide an enhanced image. 17. The apparatus of claim 16, wherein the image enhancement method further includes: sharpening the acquired image, wherein the sharpening includes finding an edge intensity value and mixing the edge intensity value into the acquired image to provide a digitally-sharpened acquired image; and wherein subtracting the mixed output image from the acquired image includes subtracting the mixed output image from the digitally-sharpened acquired image to provide an enhanced image. 18. The apparatus of claim 16, wherein performing at least one wavelet transformation process on the acquired image includes: decimating the acquired image by two to provide a first decimated image; calculating a horizontal high pass value from the first decimated image; calculating a horizontal low pass value from the first decimated image; decimating the first decimated image by two to provide a second decimated image; calculating a total high pass value from the second decimated image; and calculating a total low pass value from the second decimated image. 19. The apparatus of claim 16, wherein subtracting the mixed output image from the acquired image to provide an enhanced image includes scaling the mixed output image to allow direct subtraction of the mixed output image from the acquired image. 20. The apparatus of claim 16, wherein applying the at least one mixing value to the at least one low pass spatial frequency to produce a transformed output image includes applying the at least one mixing value to remove at least one of an over saturation and an under saturation of the acquired image. 21. The apparatus of claim 16, wherein the processing system is operatively coupled to at least one of the camera and the display device by an optical fiber. 22. The apparatus of claim 16, wherein the processing system includes at least one application specific integrated circuit. 23. The apparatus of claim 16, wherein the processing system includes at least one field programmable gate array. 24. The apparatus of claim 16, wherein the processing system includes at least one general purpose programmable processor. 25. The apparatus of claim 16, wherein the processing system includes a plurality of circuit card assemblies, each circuit card assembly having a plurality of processors disposed thereon. 26. A viewing apparatus for performing aerial refueling operations, comprising: a camera configured to capture an acquired image; a display device; and a processing system operatively coupled between the camera and the display device, the processing system being configure to perform an image enhancement method to digitally enhance the acquired image to create a digitally enhanced image, and to output the digitally enhanced image to the display device, wherein the image enhancement method includes: performing a first un-normalized wavelet transformation process on the acquired image to provide a first low pass spatial frequency; performing a second un-normalized wavelet transformation process on the first low pass spatial frequency to provide a second low pass spatial frequency; performing a third un-normalized wavelet transformation process on the second low pass spatial frequency to provide a third low pass spatial frequency; determining a dynamic range of each of the first, second, and third spatial frequencies; using the dynamic range of each spatial frequency, determining a mixing value for each low pass spatial frequency that removes at least one of an over saturation condition and an under saturation condition for each low pass spatial frequency; applying each respective mixing value to the corresponding first, second, and third low pass spatial frequencies to produce first, second, and third transformed output images, respectively reformatting the first, second, and third transformed output images to provide first, second, and third mixed output images, respectively, wherein reformatting the transformed images includes, for each wavelet transformation process performed on the acquired image: upscaling the transformed output image by two to provide a first upscaled image; calculating a horizontal high pass value from the first upscaled image; calculating a horizontal low pass value from the first upscaled image; translating the first upscaled image by �� pixel in a first orthogonal direction and by �� pixel in a second orthogonal direction; upscaling the first upscaled image by two to provide a second upscaled image; calculating a total high pass value from the second upscaled image; calculating a total low pass value from the upscaled decimated image; and translating the second upscaled image by 1/2 pixel in the first orthogonal direction and by �� pixel in the second orthogonal direction; and subtracting the first, second, and third mixed output images from the acquired image to provide an enhanced image. 27. The viewing apparatus of claim 26, wherein at least one of the first, second, and third un-normalized wavelet transformation processes includes: decimating the acquired image by two to provide a first decimated image; calculating a horizontal high pass value from the first decimated image; calculating a horizontal low pass value from the first decimated image; decimating the first decimated image by two to provide a second decimated image; calculating a total high pass value from the second decimated image; and calculating a total low pass value from the second decimated image. 28. The viewing apparatus of claim 26, further comprising: sharpening the acquired image, wherein the sharpening includes finding an edge intensity value and mixing the edge intensity value into the acquired image to provide a digitally-sharpened acquired image; and wherein subtracting the first, second, and third mixed output images from the acquired image includes subtracting the first, second, and third mixed output image from the digitally-sharpened acquired image to provide an enhanced image. 29. The viewing apparatus of claim 26, wherein determining a dynamic range of each of the first, second, and third spatial frequencies includes, for each respective spatial frequency: computing an over population of pixel intensities that are above an overflow value; and computing an under population of pixel intensities that are below an underfiow value. 30. The viewing apparatus of claim 26, wherein the processing system is operatively coupled to at least one of the camera and the display device by an optical fiber. 31. The viewing apparatus of claim 26, wherein the processing system includes at least one application specific integrated circuit. 32. The viewing apparatus of claim 26, wherein the processing system includes at least one field programmable gate array. 33. The viewing apparatus of claim 26, wherein the processing system includes at least one general purpose programmable processor. 34. The viewing apparatus of claim 26, wherein the processing system includes a plurality of circuit card assemblies, each circuit card assembly having a plurality of processors disposed thereon. 35. An aircraft, comprising: a fuselage; at least one of a boom apparatus and a hose and drogue apparatus; a camera operatively coupled to the fuselage and configured to acquire an image of at least one of the boom apparatus and the hose and drogue apparatus; an operator station disposed within the fuselage, the operator station including a display device configured to display at least one of a boom apparatus image and a hose and drogue apparatus image; and a processing system at least partially disposed within the fuselage and operatively coupled to the camera and to the display device, the processing system being configured to perform an image enhancement method to digitally enhance the acquired image to create a digitally enhanced image, and to output the digitally enhanced image to the display device, wherein the image enhancement method includes: performing at least one wavelet transformation process on the acquired image, the at least one wavelet transformation process providing at least one low pass spatial frequency; determining a dynamic range of the at least one low pass spatial frequency; determining at least one mixing value from the at least one low pass spatial frequency; applying the at least one mixing value to the at least one low pass spatial frequency to produce a transformed output image; reformatting the transformed output image to provide a mixed output image, wherein reformatting the transformed images includes, for each wavelet transformation process performed on the acquired image: upscaling the transformed output image by two to provide a first upscaled image; calculating a horizontal high pass value from the first upscaled image; calculating a horizontal low pass value from the first upscaled image; translating the first upscaled image by �� pixel in a first orthogonal direction and by �� pixel in a second orthogonal direction; upscaling the first upscaled image by two to provide a second upscaled image; calculating a total high pass value from the second upscaled image; calculating a total low pass value from the upscaled decimated image; and translating the second upscaled image by �� pixel in the first orthogonal direction and by �� pixel in the second orthogonal direction; and subtracting the mixed output image from the acquired image to provide an enhanced image. 36. The aircraft of claim 35, wherein the image enhancement method further includes: sharpening the acquired image, wherein the sharpening includes finding an edge intensity value and mixing the edge intensity value into the acquired image to provide a digitally-sharpened acquired image; and wherein subtracting the mixed output image from the acquired image includes subtracting the mixed output image from the digitally-sharpened acquired image to provide an enhanced image. 37. The aircraft of claim 35, further comprising an aerial refueling system. 38. The aircraft of claim 35, wherein the processing system is operatively coupled to at least one of the camera and the display device by an optical fiber. 39. The aircraft of claim 35, wherein the processing system includes at least one application specific integrated circuit.