haloing
 

i used paint.net to try and blur a background round a yellow rose, and this was the result:
[URL="http://www.flickr.com/photos/alexharrison101/8058909529/"][IMG]http://farm9.staticflickr.com/8458/8058909529_51ee6e2ca8.jpg[/IMG][/URL]
[URL="http://www.flickr.com/photos/alexharrison101/8058909529/"]yellow rose[/URL] by [URL="http://www.flickr.com/people/alexharrison101/"]alexharrison101[/URL], on Flickr
nasty haloing. how can i avoid this? (apart from using a wider aperture to naturally blur the background more anyway).

i don't have elements, i'm afraid, so general tips please. i used a gaussian blur after selecting the rose and inverting the selection. i did play about with the settings on the blur function, but all seemed to create this halo...is it just the high colour contrast between the yellow and the green that is affecting things?

this is the shot before the blur (just a bit of sharpening and noise reduction):
[url=http://www.flickr.com/photos/alexharrison101/8058920053/][img]http://farm9.staticflickr.com/8314/8058920053_19247c50f4.jpg[/img][/url]
[url=http://www.flickr.com/photos/alexharrison101/8058920053/]yellow rose 2[/url] by [url=http://www.flickr.com/people/alexharrison101/]alexharrison101[/url], on Flickr

maybe it's better without the blur anyway(!)...

Could it be something to do with feathering the edge of your selection? I'm not great with PS etc and especially selections but this is the first thing that springs to mind.

The only difference I can see is the 2nd image has slightly more exposure. The background in both images is out of focus and the rose is predominant anyway. Personally I don't think you need to use those tools with an image like this, consequently you wouldn't get 'haloes'. If the background had too much in focus and was distracting then yes, possibly blur the background artificially.

I agree with JohnnyM

thanks guys.

JonnyM - when i viewed it on my LCD screen, the background looked more in focus hence trying to blur it more, but having seen the two in comparison, i don't think that extra pp is needed after all(!).

do you like the shot, by the way? i think i'm actually quite pleased with it really.

Have to agree with you Alex, it is something that looks unsightly and spoils an otherwise good image.

Irrespective of how agressively you feather, you still get the dreaded halo. I just thought that it might be an idea to actually select the rose, then cut (not copy) and paste it on to a new layer. Go back to the original, now minus the rose. Reselect all, expand by a few pixels to get it to actually go in to the area previously occupied by the rose. Apply blur. Go to layer with the rose, then simply cut and paste back in to the original.

Obviously, I know nothing about paint.net, therefore do not know if it supports layers.

Alternatively, select the halo, then specifically select the colour of the halo. Once that is done, go to hue/saturation and desaturate the colour.

As a second alternative (albeit labour intensive) use the sponge tool on its 'desaturate' setting.

mkauff - yeah, paint.net does support layers, so thanks for the ideas. will have a little play (for future shots) and see what i can do!