Bilateral Filtering

Implements bilateral filtering for grayscale and color images.

Description

Bilateral filtering was proposed by Tomasi and Manduchi in 1998 as a non-iterative method for edge-preserving smoothing. For a complete description see the following publication:

C. Tomasi and R. Manduchi. Bilateral Filtering for Gray and Color Images. In Proceedings of the IEEE International Conference on Computer Vision, 1998.

This package contains a basic implementation (bfilter2.m) of their method for both grayscale and color images. In order to demonstrate the utility of bilateral filtering, the main function is used to implement an automatic image abstraction routine (cartoon.m) inspired by:

Holger Winnemoller, Sven C. Olsen, and Bruce Gooch. Real-Time Video Abstraction. In Proceedings of ACM SIGGRAPH, 2006.

A demonstration program (runDemo.m) summarizes the typical use of all included files.

A gallery of image and video abstraction results is available at: http://mesh.brown.edu/dlanman/photos/Bilateral

Acknowledgements

The author wishes to acknowledge the following in the creation of this submission:
Color Space Converter

• MATLAB release: MATLAB 7.3 (R2006b)
• Other Files: Bilateral Filtering/academy.jpg, ; Bilateral Filtering/bfilter2.m, ; Bilateral Filtering/cartoon.m, ; Bilateral Filtering/colorspace.m, ; Bilateral Filtering/einstein.jpg, ; Bilateral Filtering/mandrill.jpg, ; Bilateral Filtering/runDemo.m

[Ido Omer]

 

[Wenjing Jia]

Very easy to understand and use! Comments precede each part. Run perfectly!

[Tom Pinkiewicz]

Great filter but rather slow.
Do you know if it can be vectorised or sped up in some other way?
If there is anyone out there that knows how to speed up this code please let me know.
Good work!

[Yulia Monich]

 

[anup pandey]

 

[Zhi Zhang]

Excellent method except the speed. But a lot of papers are coming out. You can go to the SIGGRAPH07 for some information.

[kanch K]

 

[sethu madhavi]

 

[Seong Park]

good

[Daniel Oldjira Fufa]

Thanks for the code

[Giljin Jang]

Thanks for the hard work. I appreciate the code.

[DO Quoc Bao]

Thanks alot :)

[Frederic Garcia]

First of all, thank you for the code but, according to the Tomasi and Manduchi paper, I think that instead of:

G = exp(-(X.^2+Y.^2)/(2*sigma_d^2));

it should be:

G = exp(-(X-Y).^2/(2*sigma_d^2));

with respect to the GausSian distance weight in the bfilter2.m file.

Please, correct me if I'm wrong.

Bests,

[Douglas Lanman]

Frederic,

Thank you for your comments. I believe the code you referred to, specifically lines 67 and 114 in bfilter2.m, is correct as written. These lines implement the c(\xi,x) equation from Section 2.1 from the Tomasi and Manduchi paper. As they state, c is radially symmetric, with the d(\xi,x) term corresponding to the Euclidean distance between \xi and x. Expanding these expressions, the numerator of the exponent should be -(X.^2+Y.^2), not -(X-Y).^2. Your concern might come from how I've used the G matrix on these lines. This matrix is used to pre-compute c(\xi,x) for a w-by-w sized window. In this case, the origin is always the center pixel, so \sqrt((X.^2+Y.^2)) will represent the Euclidean distance of a pixel from the center of the window, where X and Y are pixel coordinates with respect to the center pixel, i.e. as given on lines 66 and 113. These geometric terms are identical for all windows, which is why I pre-computed their values. Unfortunately, the "intensity similarity" will vary for each w-by-w window. As a result, the H matrix, as given by lines 87 and 140, must be evaluated independently using a "sliding window" analysis.

Please send me an email if you have any further questions about my implementation.

Best regards,
Doug

[Hani Jamleh]

 

[Arun Kesavan]

First of all, thank you for the code but, while using with mat lab 7.0 , i am getting errors
as

??? Error: File: Z:\Bilateral Filtering\bfilter2.m Line: 29 Column: 1
Function definitions are not permitted at the prompt or in scripts.

Error in ==> runDemo at 30
bflt_img1 = bfilter2(img1,w,sigma);

please tell me how to use your code?