Making all semi-transparent pixels fully opaque

[QuinnWinters]

I need to make all semi-transparent pixels in an image fully opaque.  Saving as a gif does this, but it reduces the colors to 256 max which ruins the image.  Flatting the image also does it, but that adds a white background into the areas I need to remain transparent.  I've been all over the web trying to find an answer for this and tried all kinds of things but nothing gives me anything close to the results I want except those two things.

A lot of people seem to think that duplicating a layer over and over and then merging them will do the job but it won't because the more I duplicate the more it starts adding pixels outside the original bounds of the image.  Well that's fixable by just having all the images original pixels selected and then copying that part of the merged layer right?  Wrong!  When I then paste the copied fully opaque pixels into a new layer what do I get but semi-transparent pixels around its edges due to the inability to turn off anti-aliasing.

I can't imagine there not being a way to do this basic thing from within photoshop.  Has anyone found a solution outside of taking the image into illustrator or some other program?

[c.pfaffenbichler · Accepted solution]

Layer > Layer Mask > From Transparency

then edit the Layer Mask however necessary (Image > Adjustments > Threshold maybe).

A lot of people seem to think that duplicating a layer over and over and then merging them will do the job but it won't because the more I duplicate the more it starts adding pixels outside the original bounds of the image.

I think you are mistaken and this does not »add« pixels but makes the pixels with previously minuscule visibility/opacity noticeable.

[davescm]

Haha

c.pfaffenbichler has written his reply just as I was starting mine - he is fast

I 100% agree with his method, and the use of the threshold adjustment allows you to decide whether actually want to convert 1% opacity to 100% or whether you want the cut-off at for example 50%. I would also add a final step of Layer> Layer Mask >Apply which takes you back to the original state just with the opacity adjusted.

Dave

[QuinnWinters]

Thanks guys, that worked perfectly.  I'm baffled as to why I didn't run into that answer in any of my searches.

I think you are mistaken and this does not »add« pixels but makes the pixels with previously minuscule visibility/opacity noticeable.

That does seem logical, but does ctrl-clicking the image in the layers palette not select every active pixel in the layer?  The pixels I see getting "added" are outside of what gets selected through ctrl-clicking the layer or using the quick selection tool to select everything in the layer.  Is there perhaps a certain level of opaqueness that a pixel needs to be to get selected?

[c.pfaffenbichler]

The »marching ants« do, as far as I know, portray the 50% selected areas.

If you want to know the actual bounds of the Layer hit cmd-T without any Selection active, the transformation box should include all pixels that are even a little »opaque«.