will47 Loc: Indianapolis, IN

What is the best way to rid of haloing or artifacts? For instance on the edge of a roof.

JD750 Loc: SoCal

I had to look up the word haloing. I am including the definition below for other dummies like me:

a geometric shape, usually in the form of a disk, circle, ring, or rayed structure, traditionally representing a radiant light around or above the head of a divine or sacred personage, an ancient or medieval monarch, etc. an atmosphere or quality of glory, majesty, sanctity, or ...

Linary Loc: UK

This video might help

https://www.youtube.com/watch?v=DkTkjosZXXQ&feature=em-uploademail

I have also found that the Smudge tool can fill in the white band which may lie between the sky and the roof. (Use a large brush - 100% hard - and ease the sky to the roof.)

JohnSwanda Loc: San Francisco

couldn't access the video, but halos are usually caused by over sharpening.

Linary Loc: UK

Sorry, wrong link - this should do the trick. Also I edited my post with a note about the smudge tool.

https://www.youtube.com/watch?v=DkTkjosZXXQ&feature=em-uploademail

Cany143 Loc: SE Utah

As most folks know, haloing is a result of certain somewhat 'pushed' methods of post processing, including sharpening, dehazing, structure, and/or clarity. In some instances, it can be almost imperceptible, producing a 2-3 pixel wide 'blank,' or effectively white, space between areas of high contrast. In other instances, where higher degrees of processing have been applied, that 'haloing' effect can extend far into the lighter tone (more often than not, the typically lighter sky portions of an image). Either of these --and in my estimation, even the seemingly almost imperceptible case-- detracts from the technical quality of the image itself, so yes, correcting or compensating for the condition may be warranted.

Attached are two images (not my own) that show the easiest form of haloing to correct. Doing so takes some practice, but after the process has been done a few times, it becomes fairly easy, even if it can sometimes be time consuming--lots of dark tree branches against a light/medium value sky, for example. The process itself is relatively simple, and is as follows:

In Photoshop (and most image editing programs will have a corresponding tool), using the Magic Wand selection tool (set perhaps at 50%), select the darker value (in the instance you mentioned, I'd assume that would be the roofline). It might be necessary to add or reduce portions of that selection, and doing so might best be done by using the Lasso Selection tool (keyboard Ctrl to + the selection/keyboard Alt to - the selection). Once the selection is complete, Invert the selection such that you're now working in the lighter portion where the halo exists, and using the Clone Brush, sample from the sky/lighter area that is active, and fill in the blank halo line.

Larger --gradiated-- halos that extend far into lighter portions may require more complicated masking techniques, and since it doesn't seem that's what you've described, I won't go into those here.

Like anything, practice makes perfect. Hope that helps.

(Download)


(Download)

jweeks Loc: Phoenix

If the haloing is a result of over sharpening or increases in contrast, clarity etc. then reduce the amount of sharpening etc. until the haloing goes away. This is the basic test for over sharpening - sharpen until you see halos then back off until they go away.

mwsilvers Loc: Central New Jersey

As others have pointed out it's generally a result of over sharpening. Play with the various sharpening took and/or micro contrast tools in your software to reduce edge sharpening.

Fotoartist Loc: Detroit, Michigan

That's how I do it but I would add one thing. That is to set the Blend mode on your Clone Stamp or on your layer to "Darken". This makes it even more foolproof. In fact, sometimes you don't even need a selection or mask to do it this way.

JohnSwanda Loc: San Francisco

That's the way I do it, and it works great.

mwsilvers Loc: Central New Jersey

The only problem I have with this approach is that's it is often just a bandaid to fix a problem created by applying too much edge sharpening and contrast in the first place. I would prefer to fix the root cause of the problem rather than cover it up. Of course if one is dealing with an exported jpg file and the original edited file is not available then masking is the way to go.

JohnSwanda Loc: San Francisco

The OP's question was how to fix it. He has also been advised of the cause and how to prevent it.

mwsilvers Loc: Central New Jersey

If he has the original edited copy, reviewing and changing the applied edge sharpening is the way to fix it. It was not clear to me that the OP did not have the original with the applied edits. Now, if the edits were applied to a jpeg and saved to the only existing copy in software that doesn't have non-destructive editing, that's another thing. So I guess, the real question is, what is the format of the file and what software is he using.

tommystrat Loc: Bigfork, Montana

Ah, the wily Smudge tool! A great idea when used sparingly, a disaster when not...