I have been using dopus quite a lot for converting image sequences lately but struggled on the following:
I have a bunch of 24+8=32 bit TIFFs with RGB + alpha channel which I want to batch convert to PNGs. But I was not able to find a possibility to preserve the alpha channel.
It seems also impossible to convert to 3x16bit PNGs from 48-bit TIFFs or other formats with that color depth.
I searched to docs, I searched this forum and googled.
Any ideas to point me into the right directions?
I do not want to use ImageMagick as it breaks somehow PNG compatibility with my clients editing solution.
Dopus PNGs work fine.
Another question just came to my mind:
How do I do a recursive conversion, so that all images in a folder and its subfolders are converted to their respective destinations?
At the moment I have to select all images in a folder select convert and go on to the next folder....
Opus doesn't support TIFF alpha channels (not many programs do according to the warning Photoshop gives me when I ask it to create such a file).
Opus can read 8bpc, 16bpc and 32bpc images but can only write 8bpc images.
Opus will preserve the alpha channel if it can read it (e.g. from PNG, PSD, TGA, GIF files; including 16bpc and 32bpc images) and if you are writing to PNG (8bpc only, of course).
If ImageMagick understands TIFF alpha channels then you could probably use that to convert the TIFF files into PNG and then make Opus re-write those into 8bpc PNG files which your client's software should understand.
For converting several folders of images, a quick solution is to put the lister into Flat View mode so you can see/filter/select all of the images below the current folder at once. Another way is to use the Find Panel via the Tools menu.
First, sorry for the long delayed reply to your answer, but I got a massive hardware brakedown including several OS re-installation sessions just to find out a controller hardware was semi-broken.
Second: Thank you for your help here!
Regarding TIFFs with alpha: they are very common in the graphic world and a lot of programms can read and write that format.
I will try out your suggestons anyway.
