Posted by
Michael Schmid on
May 08, 2007; 9:47am
URL: http://imagej.273.s1.nabble.com/FT-math-motion-blur-removal-tp3699574p3699576.html
High Gabriel,
maybe it is the "divide by zero" problem mentioned by Filip
Rooms that causes your problems?
If I run the MotionBlurRemoval macro as it is, it works perfectly.
If I add "Specified Noise" with a standard deviation of 2800
on the "Motion Blurred" image, the result looks awful.
2800 is roughly the sum of the PSF pixels, and thus it is the
factor that "Motion Blurred" is multiplied by with respect to
the input image. So this amount of noise only corresponds to
one grayscale step of the input image, and it completely kills
the result.
Thus, for a "real world" pictures, where noise and
nonlinearities are present and where the point spread function
(PSF) is not exactly known, one has to use more elaborate
methods (Wiener Filter, Maximum Entropy...)
Michael
________________________________________________________________
On 8 May 2007, at 10:11, Gabriel Landini wrote:
> On Tuesday 08 May 2007 05:59:45 roger bourne wrote:
>> How do I divide an FT by another FT (or the image of its power
>> spectrum)?
>>
>> I am trying to demonstrate removal of motion blur by division of the
>> blurred image FT by the FT of the blur vector.
>
> There is this macro that shows blurring/deblurring:
>
>
http://rsbweb.nih.gov/ij/macros/MotionBlurRemoval.txt>
> I have tried to deblur other images by specfying the blur vector as
> in the
> program above, but I cannot make it work. (I must be missing
> something quite
> obvious).
>
> Please post here if you find a way of doing motion deblurring this
> way.
>
> Cheers,
>
> Gabriel