Image processing method for detail enhancement and noise reduction
One or more embodiments of the invention relate to an image processing system and method for detail enhancement and noise reduction, in which the method includes: (a) an original image is created, (b) an information measure is calculated on the basis of the original image, (c) a weighting measure is calculated on the basis of the information measure, (d) the original image is low-pass filtered with a low-pass filter to form a low-pass filtered image, (e) a high-pass filtered image is calculated by subtracting the low-pass filtered image from the original image, (f) a detail-enhanced and noise-reduced image is obtained by a high-pass image scaled with the weighting measure being added to the low-pass image. One or more embodiments of the invention additionally relate to an image processing device comprising an image recording device, an image processing unit and an image display unit.
1. An image processing method for detail enhancement and noise reduction, the method comprising:
calculating an information measure derived from original image information, in which the information measure is a spread measure or an entropy measure;
calculating a weighting measure based, at least in part, on the information measure derived from the original image information, wherein the weighting measure is greater than zero and is calculated on the basis of scaling with a constant with the calculated information measure as input data;
applying a low-pass filter to an original image to form a low-pass filtered image;
calculating an uncompressed high-pass filtered image by subtracting the low-pass filtered image from the original image;
scaling the uncompressed high-pass filtered image with the weighting measure;
compressing the low-pass filtered image; and
obtaining a detail-enhanced and noise-reduced image by adding the uncompressed high-pass filtered image scaled with the weighting measure to the compressed low-pass filtered image.
2. The image processing method according to claim 1 , wherein the weighting measure is calculated on the basis of a look-up table with the results for the calculated information measure as input data.
3. The image processing method according to claim 1 , wherein the information measure is the spread measure, and wherein the spread measure is a standard deviation.
4. The image processing method according to claim 1 , wherein the original image information comprises the original image.
5. The image processing method according to claim 1 , wherein the original image information comprises more than one image.
6. An image processing device configured to perform the image processing method according to claim 1 , wherein the image processing device comprises a camera and/or an infrared camera.
7. The image processing method according to claim 1 , further comprising:
compressing the detail-enhanced and noise-reduced image; and
displaying the compressed detail-enhanced and noise-reduced image.
8. The image processing method according to claim 1 , wherein the information measure is the entropy measure.
9. An image processing device comprising:
an image recording device configured to create an original image; and
an image processing unit configured to:
calculate an information measure based on original image information, wherein the information measure is a spread measure or an entropy measure,
calculate a weighting measure based, at least in part, on the information measure, wherein the weighting measure is greater than zero and is calculated on the basis of scaling with a constant with the calculated information measure as input data,
apply a low-pass filter to the original image to form a low-pass filtered image,
calculate an uncompressed high-pass filtered image by subtracting the low-pass filtered image from the original image,
scale the uncompressed high-pass filtered image with the weighting measure,
compress the low-pass filtered image, and
obtain a detail-enhanced and noise-reduced image by adding the uncompressed high-pass filtered image scaled with the weighting measure to the compressed low-pass filtered image.
10. The image processing device according to claim 9 , wherein the image recording device is an infrared (IR) camera.
11. The image processing device according to claim 9 , further comprising an image display unit configured to visualize the detail-enhanced and noise-reduced image, wherein the detail-enhanced and noise-reduced image is compressed prior to visualization in the image display unit.
12. The image processing device according to claim 9 , wherein the weighting measure is calculated in the image processing unit on the basis of a look-up table with the results for the calculated information measure as input data.
13. The image processing device according to claim 9 , wherein the information measure is the spread measure, and wherein the spread measure is a standard deviation.
14. The image processing device according to claim 9 , wherein the original image information comprises the original image.
15. The image processing device according to claim 9 , wherein the image recording device comprises an optical sensor.
16. The image processing device according to claim 9 , wherein the image processing unit is further configured to compress the detail-enhanced and noise-reduced image using histogram equalization prior to visualization in an image display unit.
17. The image processing device according to claim 9 , wherein the image recording device comprises an image sensor.
18. The image process device according to claim 9 , wherein the low-pass filter is an edge-preserving low-pass filter.
19. The image processing method according to claim 1 , further comprising capturing the original image using an image sensor.
20. The image processing method according to claim 1 , wherein the low-pass filter is an edge-preserving low-pass filter.