Legacy ImageMagick Discussions Archive

ImageMagick-6.8.5-Q16 with Photoshop CS5.

It's like there's something buried in the TIFF header that is making PS think this image has premultiplied alpha when it shouldn't.
I just tried it in CS3 - same as you - it shows up with a separate alpha channel. Stranger and stranger.
Now what is ...

I just did an itentify -verbose on the image that IM gives me versus the same image manually edited to have a separate alpha channel, and diff'd the two results. The only things that show up different in the manually edited version are these:

tiff:document: gray.tif missing from the IM version ...

Just download it from the displayed images above.

Wow. Weird. I downloaded the TIF and it shows as the 'hybrid' style in my PS and my modelling tools, yet on your side it shows as separate alpha channels. So now I suspect there's something in the header that isn't being set that MAC PS doesn't ...

Fred
Yeah - TIFs get saved with the alpha even if it's "turned off" in the channel list. The channel list in Photoshop is showing you all the channels available in the image - been working with PS since version 2 so I'm intimately familiar with it :)

What's odd is that those screenshots you show ...

Hmm.
Using those CLIs still gives me the 'baked in' transparency. My original image, in PS, shows as 4 channels - r,g,b and a. The resulting image only ever shows a single channel.
It's not just PS either - I use a couple of 3D modeling tools (Max, Maya etc) and they all fail to see any alpha ...

Hello.
I've scoured the forums for a couple of days now and found multiple topics that all seem to skirt around the issue, but none that answer my question:
How can I convert an image to TIFF format and preserve the alpha channel?

Windows 7, ImageMagick-6.8.5-Q16
This is my basic CLI:

convert ...