Comments on: Image deblurring - Introduction

By: Steve

Steve — Mon, 17 Aug 2009 18:29:41 +0000

Yuan—Usually the only time you know the blur function is when you have some model of the physical imaging processing that includes the blurring mechanism. Deblurring when you don’t know the blur function is called blind deblurring in the literature. You might try the function deconvblind.

By: yuan

yuan — Sat, 15 Aug 2009 14:15:29 +0000

I wonder how to calculate the deblur parameter and deblur type? Without these information, it is hard to deblur the degraded image.

By: Steve

Steve — Thu, 23 Apr 2009 11:11:09 +0000

Ray—That doesn’t look like a very plausible three-dimensional PSF to me. Are you really just trying to do several two-dimensional deblurring operations? Then do that in a loop. You might want to give the deconvwnr function a try.

By: Ray Caldeira

Ray Caldeira — Wed, 22 Apr 2009 17:01:56 +0000

Ok Steve, I got it! :)
But now that I made it, or think I did… my implementation is not succeeding. Instead of deconvolving, it’s blurring the images and I think this was supposed to work…

Below is what I got for a simple deconvolution function with “stack_img(x, y, z)” as the input:

sigma = 2; rad = 32;
psf1 = fspecial(’gaussian’, [rad rad], 2*sigma) +eps;
psf2 = fspecial(’gaussian’, [rad rad], sigma) +eps;
psf3 = fspecial(’gaussian’, [rad rad], 2*sigma) +eps;

psf_3D = cat(3, psf1, psf2, psf3); % ‘3D’ 2 inverted gaussian cones

fpsf = fftn(psf_3D, size(stack_img));
img_temp = ifftn((fftn(stack_img)).*conj(fpsf))./abs(fpsf.^2 + 1e-2);
img_out = real(img_temp);

Thanks again!

By: Steve

Steve — Wed, 22 Apr 2009 16:23:46 +0000

Ray—All of the Image Processing Toolbox deblurring functions support multidimensional images and PSFs. If you’re coding things up yourself based on the math, there’s no significant difference between the two-dimensional and n-dimensional cases, other than using fftn instead of fft2.

By: Ray Caldeira

Ray Caldeira — Wed, 22 Apr 2009 15:37:40 +0000

Hi Steve!

I’m learning deconvolution and I kind of understood what you got here but what if I had a stack of images and needed to perform a 3D deconvolution? How would I fit the fftn function here to work with a gaussian PSF? Thanks for your time and care ;)

By: Steve

Steve — Thu, 02 Apr 2009 17:26:21 +0000

Sudeep—You might try using the deconvblind function in the Image Processing Toolbox.

By: Sudeep Singh

Sudeep Singh — Mon, 30 Mar 2009 08:26:10 +0000

Hey, i really need your help on this. i’m need to deblur an image which was directly captured in blurred form by the cam. So, i need a code to estimate the psf so i can use the deconvolution procedure. M really stuck as i cant find that anywhere. if you can gimme a link to follow or some source, that would be amazing! thanks

By: Steve

Steve — Wed, 18 Feb 2009 01:49:32 +0000

Amit—You need to either provide an estimate of the PSF function, or you use something like deconvblind to simultaneously estimate the PSF and the deblurred image.

By: Amit Raj

Amit Raj — Sat, 07 Feb 2009 12:34:52 +0000

Thank you, steve.
I am an undergraduate student. Recently I have started learning about the image processing, image restoration. The deblurring part is fascinating me.
in this experiment u yourself create a distortion(PSF),and noise, and out convolved it with the original image and restore to similar original image with the help of inverse filter,(this is de-convolution, if I am right).
What if the picture is blurred? And you have to make it deblurred? Do you apply the same process?
Can you help me out, I am still in learning phase, and sorry for my stupidity