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Plugin for removal of HOT PIXELS ??

Posted: Wed Nov 22, 2006 9:36 am
by pfgbel47
Hello,
With long exposure times, I get of course hot pixels in my pics and I'm looking for a plugin I could add to my PhotoShop 6.0 which could help me to remove these numerous hot pixels. I already searched and searched and I tried the "Harry's Filters" but don't find the required filter fo my precise job :cry: !
Can somebody help me ?
Thank you in advance !
Pol

Posted: Wed Nov 22, 2006 12:29 pm
by Ilya Razmanov
Not a plugin but possible solution: at the same conditions, take a shot with your lense closed by cap. It will give you the image containing nothing but hot pixels and heat signal. Now with Image - Apply Image use this new image to "Subtract" it from photo.

Hope this helps.

RE- Photoshop - compatible Plugins

Posted: Wed Nov 22, 2006 1:21 pm
by pfgbel47
Thanks a lot for your quick reaction !
All this is confused for me, sorry.
Do you mean there is a function called "image" and "apply" and "substract" in PhotoShop 6.0 ??
I suppose I have to make a layer with the "black" picture but how do I come back to apply on the original pic ?
Pol

Posted: Wed Nov 22, 2006 1:35 pm
by Ilya Razmanov
I described you the sequence of menu items you should click to go to "Apply Image" function. In the dialog here, you'll see the option to choose one of currently open images (remember that both of the photo and "noise" images should be open at a time) as "source", the "target" being set to currently active image automatically. You'll also see "Blend" option, where you should choose "Subtract". Source must be your noise image, target must be the photo image, subtract must be the mode. In preview of the target image you should hopefully see some improvement, in case my idea was right :-)

Posted: Wed Nov 22, 2006 1:35 pm
by Ilya Razmanov
I described you the sequence of menu items you should click to go to "Apply Image" function. In the dialog here, you'll see the option to choose one of currently open images (remember that both of the photo and "noise" images should be open at a time) as "source", the "target" being set to currently active image automatically. You'll also see "Blend" option, where you should choose "Subtract". Source must be your noise image, target must be the photo image, subtract must be the mode. In preview of the target image you should hopefully see some improvement, in case my idea was right :-)

Posted: Wed Nov 22, 2006 1:58 pm
by pfgbel47
It's perfect, I followed your plan, step by step, and indeed the result is remarquable, only a few spots are still present but it's now much more easier to get them out as they are not so numerous !
:D I want to thank you for your help !
Pol

Posted: Wed Nov 22, 2006 2:12 pm
by Ilya Razmanov
Glad to hear it helped. In fact, I suppose for this plan to work better, detector temperature during taking "blind" (that is, "noise") shot should be equal to that during taking the photo. I'm also not so sure if interpolation or some "smart" feature in camera may came to play and spoil things, because my approach is based on just dumb arithmetics and doesn't like any smart filtering to get in :-) Another source for imperfection may be dynamic noise - true hot pixels give static noise, that is, they always sit in the same coordinates, so we may record them, isolated from the image (over the dark lense cap), then simply subtract them from the photo. If the noise get some dynamic component, this approach no longer work.

Anyway, if it makes some improvement for you, I'm happy to hear that.

Posted: Wed Nov 22, 2006 3:46 pm
by HaraldHeim
Other options are the free Hot Pixel plugin from http://www.redpawmedia.com/ and the HotPixels Eliminator from http://www.mediachance.com/digicam/hotpixels.htm

I haven't tried them myself so far, because I never had such a hot pixel problem in one of my photos. Or maybe I didn't notice it?!

Thanks ...!

Posted: Wed Nov 22, 2006 8:52 pm
by pfgbel47
I really want to thank you both !
Ilya, the advice you suggested gave me very high satisfaction, as I said only a few points had to be removed manually, it was great !
To you HaraldHeim thank you also because these tools could be very helpfull to me in a near future, I'll try to download them as soon I'm up tomorrow morning and I shall try to see the eventual differences I get compared to the solution of Ilya !

Thanks again for your help, it makes me happy to meet new friends like you on the net who are ready to offer their help... that's real friendship !
Pol

Posted: Thu Nov 23, 2006 11:01 am
by HaraldHeim
Manual solutions are often better (if you do it correctly), but plugins are a time saver if you need to process a large number of photos.