comp.lang.idl-pvwave archive: archive » finding star-like objects in images

Home » Public Forums » archive » finding star-like objects in images

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: finding star-like objects in images [message #94859 is a reply to message #94858]

Wed, 08 November 2017 02:25

Markus Schmassmann
Messages: 129
Registered: April 2016

Senior Member

On 11/08/2017 11:12 AM, Helder wrote:
> I'm not an astronomer and I guess that this is something that
> astronomers have been confronted with quite often in their lives.
> I have a detector where particle events generate intensity across
> some pixels (2-5 x 2-5) [*]. Typically their integral intensity is
> constant (lets say 100 +/- 20). These events show over a noisy bkg.
> Apart from having a constant intensity, these events are similar to
> stars (that have a varying luminosity).
>
> What approaches are typically used for detecting/locating such
> events?
>
> Any IDL solution readily available out there?
>
> Thanks for reading so far and for any suggestions.
>
> [*] - threshold methods would not work very well, because the total
> intensity of 100 may be distributed over 2x2 pixels (~25 per pixel)
> or 5x5 (~10 per pixel).
Hi Helder,

just a guess, but have you tried

star=where(smooth(img,[5,5]) gt 100./5^2/2)

you will have to change the threshold value and maybe also how much
smoothing you apply, but it could work.

good luck, Markus

Report message to a moderator

[Message index]

		finding star-like objects in images By: Helder on Wed, 08 November 2017 02:12
		Re: finding star-like objects in images By: Markus Schmassmann on Wed, 08 November 2017 02:25
		Re: finding star-like objects in images By: Helder on Mon, 27 November 2017 03:29

Previous Topic:	Re: Generating a grid in the 3D,4D,5D...N space - Advice/Combinatory/Matrices
Next Topic:	Context Menu ib widget_tree

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 11:39:19 PDT 2025

Total time taken to generate the page: 0.00493 seconds