Black background when open a transparent .tif file which was rendered from Blender

[Sonny Sonny]

Hi, I got a weird issue with AP V2. When I opened a transparent ".tif" file which was rendered from Blender, AP did not open as transparent background, it did auto fill the transparent area of the image with black color. I've tested with different format: PNG, Targa, Webp,... it works fine.

❌ I've tried to:

- Change all color profile of the Blender render setting => Not work.

- Use "File / Open" menu instead => Not work.

- Remove, re-install, update to latest Nvidia Studio / Game driver => Not work.

 

✅ This bug did not happen with/when:

- AP V1

- Other transparent image format: png, targa, webp,...

- Create new AP transparent background then drag/drop the rendered .tif file into that new AP file.

I also uploaded the tif file, the color profile of the image and the video that demonstrates the bug then you can see the issue more clearly.

Anything I can do to fix this weirdo? As an 3D artist, especially CGI photography, rendered .tif file is a must working file I do everyday, I hope this could be fix soon. Thanks for stopping by 🙏

cube tif test.tif

[Sonny Sonny]

Update: I just tried to export .tif file with 16 bit color depth then it worked fine. I don't know why it only did happen with 8 bit depth .tif

You can test with my attached files.

render 8 bit.tif render 16 bit.tif

[Pauls]

I've logged that - thanks for the files

[Sonny Sonny]

On 12/22/2022 at 10:32 PM, Pauls said:

I've logged that - thanks for the files

I hope this could be fixed soon and deployed on the next released 🙏

[DaQuizz]

Yes we hope so, it is not fixed yet version 2.0.3.

But I might have found a solution at least for now.  I have found out that there is a line in channels that says "not assigned alpha-channel" (why should that be?). When I right-click on that channel and select "load alpha in background" I get the alpha working and I can toggle alpha on and off.

As you mentioned every thing else works fine but opening .tif file with trans background does not, at least not coming from e.g. Blender. After saving .tif in AP with trans Background it works when reopen.

Even placing works...

[SrPx]

This solution is very similar to what was found out recently with a BMP of the 32 bits kind (the  glitch was different: it wouldn't show anything, just a transparent canvas). It gets solved doing a similar trick to what you just mentioned. As it'd be something to do in general with transparency/32bit (although this  tiff was saved in 8 bit) or transparency channel info, I don't know. But what I mean is that might not be just file format specific.

[Sonny Sonny]

I hope this could be assembled soon.

[DaQuizz]

Unfortunatly nothing happend so far yet. The only workaround is still as mentioned to load unassigned alpha channel and then you are good to go.
I also hope they get it fixed in the next update...

[James Ritson]

Hi @DaQuizz and @Sonny Sonny, this isn't actually a bug but rather an intentional behaviour: the TIFF metadata from Blender will be written as having unassociated alpha. Previously, Photo was ignoring this metadata and associating the alpha channel, which was actually undesirable for certain workflows. For example, when you save a final beauty pass from vRay without a separate alpha pass layer, it will write unassociated alpha data into the TIFF. This allows the user to optionally remove the background detail using the alpha channel, but they may not wish to: instead, they may just want to use that alpha data for other types of masking such as affecting just the sky or foreground with adjustments.

I did a tutorial on the process here: 

 

Hope that makes sense and helps?

[Sonny Sonny]

@James Ritson Thanks but I am still confusing about the issue. Why a small web-app like Photopea has none issue at all with these type of Tif/Tiff files?

[James Ritson]

9 hours ago, Sonny Sonny said:

@James Ritson Thanks but I am still confusing about the issue. Why a small web-app like Photopea has none issue at all with these type of Tif/Tiff files?

Hi @Sonny Sonny, as I mentioned above it's not an issue. Possibly Photopea does not interpret unassociated alpha?