Canny Detector

[Jonathan Andrade Silva]

Hi
Where can I find the source of the detector of border of Canny?

Thanks in advance
Jonathan

[Frederic V. Hessman]

I needed a plugin which watches a directory looking for new images  
(e.g. as produced by a camera or other program) and quickly produced

        http://www.astro.physik.uni-goettingen.de/~hessman/ImageJ/ 
Directory_Watcher/

Unfortunately, most ftp programs give the right names to files before  
they are finished being transfered, which results in attempts to load  
incomplete files.   Even if one makes the watcher wait a long time  
before looking, there's always the problem of hitting a transfer at  
the wrong moment.  Any ideas other than using rsync (which you can  
tell to use temp files)?

Rick

------------------------------------------------------------------------
------------------------
Dr. Frederic V. Hessman     [hidden email]
Institut für Astrophysik          Tel.  [phone]
Friedrich-Hund-Platz 1         Fax [phone]
37077 Goettingen                 Room F04-133
http://www.Astro.physik.Uni-Goettingen.de/~hessman
------------------------------------------------------------------------
-------------------------
MONET: a MOnitoring NEtwork of Telescopes
http://monet.Uni-Goettingen.de
------------------------------------------------------------------------
-------------------------

[William Godinez]

How about checking if the file transfer is finished? One naive approach
could be to check whether a file is "growing": (1) check file at t_k,  store
file_size_k; (2) check file at t_k+1, store file_size+k+1; (3) compare file
sizes to determine subsequent action (load or wait or bypass).

This obviously depends on the speed of your file transfer; I am sure there
are better ideas on how to do this.

Regards,

William



On 12/15/06, Frederic V. Hessman <[hidden email]>
wrote:

>
> I needed a plugin which watches a directory looking for new images
> (e.g. as produced by a camera or other program) and quickly produced
>
>         http://www.astro.physik.uni-goettingen.de/~hessman/ImageJ/
> Directory_Watcher/
>
> Unfortunately, most ftp programs give the right names to files before
> they are finished being transfered, which results in attempts to load
> incomplete files.   Even if one makes the watcher wait a long time
> before looking, there's always the problem of hitting a transfer at
> the wrong moment.  Any ideas other than using rsync (which you can
> tell to use temp files)?
>
> Rick
>
> ------------------------------------------------------------------------
> ------------------------
> Dr. Frederic V. Hessman     [hidden email]
> Institut für Astrophysik          Tel.  [phone]
> Friedrich-Hund-Platz 1         Fax [phone]
> 37077 Goettingen                 Room F04-133
> http://www.Astro.physik.Uni-Goettingen.de/~hessman
> ------------------------------------------------------------------------
> -------------------------
> MONET: a MOnitoring NEtwork of Telescopes
> http://monet.Uni-Goettingen.de
> ------------------------------------------------------------------------
> -------------------------
>

[ctrueden]

Hi Frederic,

If you have control over the FTP upload portion of the software, you
could have the uploader write a small "done" file when it's finished,
then act as soon as that file appears. This would prevent the
directory watcher from triggering if the transfer died in the middle
for some reason.

Or if the directory watcher is watching for files of a specific
extension, you could have the FTP upload portion first upload the
files as .tmp, then when it is finished rename them to .tif or
whatever extension the watcher is looking for.

-Curtis

On 12/15/06, Frederic V. Hessman <[hidden email]> wrote:

> I needed a plugin which watches a directory looking for new images
> (e.g. as produced by a camera or other program) and quickly produced
>
>         http://www.astro.physik.uni-goettingen.de/~hessman/ImageJ/
> Directory_Watcher/
>
> Unfortunately, most ftp programs give the right names to files before
> they are finished being transfered, which results in attempts to load
> incomplete files.   Even if one makes the watcher wait a long time
> before looking, there's always the problem of hitting a transfer at
> the wrong moment.  Any ideas other than using rsync (which you can
> tell to use temp files)?
>
> Rick
>
> ------------------------------------------------------------------------
> ------------------------
> Dr. Frederic V. Hessman     [hidden email]
> Institut für Astrophysik          Tel.  [phone]
> Friedrich-Hund-Platz 1         Fax [phone]
> 37077 Goettingen                 Room F04-133
> http://www.Astro.physik.Uni-Goettingen.de/~hessman
> ------------------------------------------------------------------------
> -------------------------
> MONET: a MOnitoring NEtwork of Telescopes
> http://monet.Uni-Goettingen.de
> ------------------------------------------------------------------------
> -------------------------
>

[Gabriel Landini]

On 12/15/06, Frederic V. Hessman wrote:
> > Unfortunately, most ftp programs give the right names to files before
> > they are finished being transfered, which results in attempts to load
> > incomplete files.   Even if one makes the watcher wait a long time
> > before looking, there's always the problem of hitting a transfer at
> > the wrong moment.  Any ideas other than using rsync (which you can
> > tell to use temp files)?

A suggestion (not sure how useful it could be):
If the images are taken always with the same camera, then one could save them
uncompresed (so they are all the same size). You can then check the file size
in the destination folder and when they reach the expected size, then they
have been transferred.

I hpe it helps

Gabriel

[Thomas Boudier-2]

Hi,

I have put a version of the canny-deriche filter on the imagej wiki site :
http://imagejdocu.tudor.lu/Members/tboudier/plonearticle.2006-07-12.2524848149

Thomas

> Hi
> Where can I find the source of the detector of border of Canny?
>
> Thanks in advance
> Jonathan
>
> .
>


--
/*****************************************************/
 Thomas Boudier, MCU Université Pierre et Marie Curie
 Imagerie Intégrative,Institut Curie - INSERM U759.
 Tél : [phone]  Fax : [phone]
/*****************************************************/


 

[Albert Cardona]

William's idea is good, but for a final check that the file is complete,
you can make your plugin read the image header. Set your microscope to
acquire as uncompressed tiff ( so the size is predictable) and then
either just use the file size (if all images have the same dimensions)
or read the tiff header for the width and height values. The size of the
image is then the size of the tiff header plus width*height bytes if
8-bit, or width*height*4 if RGB (integers have 4 bytes).
Otherwise set a reasonably long time to wait after the size is not
growing anymore. If the image acquisition is continuous, you can flag an
image as readable if another, newer image has been started to be
recorded in the folder.

Albert

[Gabriel Landini]

On Saturday 16 December 2006 10:26, Thomas Boudier wrote:
> I have put a version of the canny-deriche filter on the imagej wiki site :
> http://imagejdocu.tudor.lu/Members/tboudier/plonearticle.2006-07-12.2524848
>149

Hi, is there an option or separate plugin to do the non-maximal suppression?
to obtain the binary edges?

Regards,

G.

[Thomas Boudier-2]

Gabriel Landini a écrit :
> On Saturday 16 December 2006 10:26, Thomas Boudier wrote:
>  
>> I have put a version of the canny-deriche filter on the imagej wiki site :
>> http://imagejdocu.tudor.lu/Members/tboudier/plonearticle.2006-07-12.2524848
>> 149
>>    
>
>  
Hi Gabriel,

Humm... that's something I would like to do, I have updated the plugin
so the angle of the edges are displayed. A first step towards
non-maximal supression...

regards

Thomas

> Hi, is there an option or separate plugin to do the non-maximal suppression?
> to obtain the binary edges?
>
> Regards,
>
> G.
>
> .
>
>  

--
/*****************************************************/
 Thomas Boudier, MCU Université Pierre et Marie Curie
 Imagerie Intégrative,Institut Curie - INSERM U759.
 Tél : [phone]  Fax : [phone]
/*****************************************************/