Saving 32-bit floating point rgba tiffs

[Michael Allman]

I am able to load 32-bit floating point rgba tiffs exported from Apple's Image IO framework into Affinity Photo. However, when I save it, Affinity Photo writes the file as 16-bit. Can you add support for saving/exporting 32-bit tiffs in a future release?

OpenEXR provides this capability, however it is seriously handicapped in that it has no metadata support.

[James Ritson]

Hi @Michael Allman, have you tried using the File>Export dialog and clicking the More button? This allows you to export 32-bit linear floats with the TIFF format.

Presumably you are referring to write back when using File>Save? This should probably be looked at if it’s not writing the correct pixel format back…

Hope that helps,
James

[R C-R]

18 minutes ago, James Ritson said:

Hi @Michael Allman, have you tried using the File>Export dialog and clicking the More button? This allows you to export 32-bit linear floats with the TIFF format.

I do not seem to have a 32 bit TIFF export option in my copy of AP 1.10.5 on my Mac. The only 32 bit options I have in the More window are for OpenEXR & Radiance.

What am I missing?

[James Ritson]

7 minutes ago, R C-R said:

I do not seem to have a 32 bit TIFF export option in my copy of AP 1.10.5 on my Mac. The only 32 bit options I have in the More window are for OpenEXR & Radiance.

What am I missing?

It's been there since 1.5 (when 32-bit support was introduced), but unfortunately there isn't an explicit preset for it, so it's somewhat hidden...

[walt.farrell]

31 minutes ago, James Ritson said:

but unfortunately there isn't an explicit preset for it,

I think that's it, James. We automatically try the Preset field, which only offers RGB 8-bit and RGB 16-bit, and don't think to try More and the Pixel Format dropdown.

 

[NotMyFault]

1 hour ago, James Ritson said:

It's been there since 1.5 (when 32-bit support was introduced), but unfortunately there isn't an explicit preset for it, so it's somewhat hidden...

Unfortunately the UI is not the best source of truth to find out what functions actually works or don't work: 

• PNG Export offers a palletised option with "custom" setting, probably since 1.5, which never worked and still does not work.
• Mask layers offer blend modes and blend ranges - none of them work.
• Affinity happily opens TIFF files with GREY/32 bit depth - but interprets them wrong. It cannot save or export TIFF with GREY/32.

[thomaso]

5 hours ago, NotMyFault said:

Unfortunately the UI is not the best source of truth to find out what functions actually works or don't work:
(...)
Mask layers offer blend modes and blend ranges - none of them work.

+ Mask layer opacity affects the entire layer below or the parent layer – but not the mask.
+ Mask layers may get a layer fx applied – with no effect.
+ Mask layers may get an adjustment layer nested – with no effect.

[NotMyFault]

3 hours ago, thomaso said:

+ Mask layer opacity affects the entire layer below or the parent layer – but not the mask.
+ Mask layers may get a layer fx applied – with no effect.

These are examples to fit in the row I started (non-working UI)

3 hours ago, thomaso said:

Mask layers may get an adjustment layer nested – with no effect.

I rate this as a different kind of bug. It should work, and works partially / buggy in rare cases. It’s part of a class of general bugs with nested adjustment layers impacting the alpha channel. As mask layers are pure alpha, they are almost always impacted, but the issues affect pixel layers (with alpha), too.

[Michael Allman]

On 7/1/2022 at 1:03 PM, James Ritson said:

Hi @Michael Allman, have you tried using the File>Export dialog and clicking the More button? This allows you to export 32-bit linear floats with the TIFF format.

Presumably you are referring to write back when using File>Save? This should probably be looked at if it’s not writing the correct pixel format back…

Hope that helps,
James

Hi James,

Thank you. I completely missed the option under the "More" button. I was confused by the fact that AP is not saving my modified 32-bit tiff back as a 32-bit tiff, even though the document pixel format is 32-bit rgb. This sounds like a bug to me...

[Michael Allman]

FYI, I've reported this as a bug in the bug forum https://forum.affinity.serif.com/index.php?/topic/164613-ap-overwrites-32-bit-tiff-with-16-bit-tiff-when-saving/.