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Re: Image quality evaluation

Posted by Jennifer West on Aug 30, 2006; 10:00pm
URL: http://imagej.273.s1.nabble.com/Image-quality-evaluation-tp3695062p3695066.html

Hi Emmanuele and everyone,

Way back in July we were discussing image quality assessment. I have  
been experimenting with using Sobel filters for assessing quality.  
I've written a plugin that ranks images by their edges using the  
"find edges" routine that is built into ImageJ.

If anyone is still working on this I would be interested to see how  
the results from this routine compares to routines that others may be  
using. Please let me know.

The plugin may be downloaded from:
http://www.umanitoba.ca/faculties/science/astronomy/jwest/plugins.html

Cheers,
Jennifer

___________________________________
Jennifer West, Instructor
Department of Physics and Astronomy
378 University College
University of Manitoba
Ph. 204-474-9501


On 12-Jul-06, at 4:06 AM, Emmanuele Sordini wrote:

> Hello Hennifer!
>
> On 7/11/06, Jennifer West <[hidden email]> wrote:
>>
>> Hi Emmanuele,
>>
>>
>> I wrote a plugin that computes a "quality factor" based on a method
>> that I read at this site:
>> http://acquerra.com.au/astro/software/ppmcentre/
>
> According to the webpage, this method is the same as the one used in
>> Registax.
>
>
> Unfortunately, the source code of ppmcentre is not available (link  
> to tar
> file broken?), so I can't comment on that method. But if it's used in
> Registax it should be quite reliable. Could you perhaps provide me  
> with the
> latest version (i.e. tar archive) you have?
>
> BTW, my webcam processing application of choice is Iris. For sure  
> it's way
> less user-friendly than Registax, but it's also more powerful.
>
>
> I've only tested my plugin on two stacks of images (one of Jupiter
>> and one of Saturn) and it seems to work reasonably well. But I would
>> be very happy if you would like to test it and let me know how it
>> works on your images. I've just posted it to my website and you may
>> download it here:
>> http://www.umanitoba.ca/faculties/science/astronomy/jwest/ 
>> plugins.html
>
>
> Nice website! I also appreciate the "Save as FITS" plugin, which
> inexplicably is not provided with ImageJ.
>
> Let me know how this works for you!
>
>
> I've done a very quick trial run on a 20-frame sample from an AVI  
> file of
> mine. Here's the outcome (frame numbers from 1 to 20 sorted in  
> decreasing
> quality order) as compared with the one from Iris:
>
> Iris                            ImageQuality plugin
>                  Frame #       Score (times 10^11)
> 15         10    9.06731706255
> 19         15    9.06724426944
> 12         9     9.06694117833
> 17         1     9.06688137711
> 20         2     9.06688128297
> 10         18    9.06685968411
> 13         20    9.06681322122
> 11         6     9.06679849284
> 4          17    9.06679361922
> 8          7     9.06678465756
> 9          16    9.06666556767
> 18         19    9.06645265785
> 3          4     9.06644101764
> 5          12    9.06637309293
> 14         3     9.06632877069
> 1          8     9.06630080046
> 2          14    9.06627718458
> 7          13    9.06626186028
> 6          5     9.06622588776
> 16         11    9.06609830427
>
> As you can see, it turned out to be quite different from Iris. But  
> we know
> that probably "no two image quality indicators are alike" :-)
>
> Emmanuele