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Very basic problem importing tiff images with alpha
So, i need to touch up some stop motion footage, and for that purpose, I made a first chroma keying pass in AE, and then exported a tiff sequence, for me to finish up in PS.
Now, whenever I import the images to PS as a sequence, there is no alpha. Just a big black background, and a plain RGB sequence.
Whenever I import each image individually, I get an RGBA image, but i still see the black background, and for the life of me, i just want to import a transparent image and see a transparent image. What am I missing? This is really getting on my nerves today.
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4 Replies
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Well, for what it’s worth, exporting the images as PNGs makes them work right away. Why does PS treat Tiff and PNG images with transparency differently? Now i’m curious.
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That is expected behaviour. A tiff does not officially support transparency (Photoshop introduced a multi-layered tiff format at some point), but does support alpha channels. This alpha channel is present in the channel palette, and can be used to generate a layer mask, for example.
A PNG file supports true transparency. In this case the transparency is not saved as an alpha channel, but as transparency in the pixels bits. (As far as I know.)
In Photoline a tiff with an alpha channel is loaded up as a two layer file, with the alpha channel layer at the top of the layer stack, and hidden. By activating it as a clipping mask, the background becomes “transparent”.
It depends a bit on the software used how a tiff’s alpha channel is treated. And tiff files can contain more than one alpha channel.
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Thanks a lot! Now i know something new.
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If you would prefer to use tiff for another reason then you could create a Photoshop action that creates a selection from the alpha channel and then masks unlocked layer.
Alternatively you can render directly to PSDs from after effects. PSDs use lossless compression like pngs but support higher bit depths than png.
Darby Edelen
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