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Thin white outlines around objects after “New Layer via Cut” – why???
I’m selecting a part of the image using the magnetic lasso tool, then going “New layer via cut” — and it results in a a thin white line where my selection was. Why don’t the two layers merge seemlessly? Are there any tricks to remove the thin white outline? Thanks.
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3 Replies
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You’re seeing the tiny difference between the selection and the selected. Do you see this at 100%? Try doing a selection, then feather 1px, then copy to a new layer.
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Jonathan Ziegler
http://www.electrictiger.com
520-360-8293 -
Yes even at 100%. Feathering may help but I’m kind of perplexed as to why this happens in the first place. They’re screen grabs from a HD video, so 1920×1080, 72 DPI. Could it be an issue with resolution?
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This happens because the selection is anti-aliased and alpha blending between the semi-transparent pixels (like those that result from anti-aliasing) does not resolve to a fully opaque pixel.
In After Effects you can use the ‘Alpha Add’ blend mode to fix problems like this but that’s not available in Photoshop.
The easy solution is to uncheck ‘anti-alias’ from the selection tool.
However, my recommendation would be to duplicate the full base layer and use a layer mask instead of using Layer Via Cut. If you save your selection you can use it for the layer mask. You can copy the layer mask to the lower base layer and invert it. To remove the anti-aliasing overlap issue you can then select the top layer’s layer mask and use Filter > Other > Maximum with a radius of 1. This will expand the mask by 1 pixel.
Darby Edelen
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