Convert jp2 with alpha channel to tif

[dcarubia]

I have over a thousand 64bit RGBI scans from Vuescan. They all contain RGB channels as well as one alpha channel that contains the infrared scratch information needed for ICE scratch and dust removal. Needless to say, they take up alot of space! I want to try to archive these scans using jpeg2000.

All of these scans use the tif format. Using ImageMagick I've been able to successfully test the conversion from tif to jpeg2000. The Jpeg2000 file preserves the alpha channel. Using photoshop CC 2015 I can convert the jpeg2000 back to a tif which can subsequently be used by the Vuescan software to "scan from a file."

While the process described above does work, I'd like to be able to convert from jpeg2000 to tif using the "convert" program.

I've tried to convert the jpeg2000 file to a tif file using ImageMagick's "convert" program, but the alpha channel is not preserved in the resulting tif.

So, if I want to convert a jpeg2000 file with RGB channels and one alpha channel to tif and preserve the alpha channel, what options are available to accomplish that?

[dlemstra]

Can you share one of your images so we can see why the alpha channel is not saved to the TIFF file?

[fmw42]

Please also provide your version of Imagemagick and platform (whenever you ask a question). And also your exact command line.