EXR export issue

   4139   3   1
User Avatar
Member
2035 posts
Joined: Sept. 2015
Offline
Hello,

I was hoping someone might be able to comment on what might be going on with creating image sequences in uncompressed exr format with Mantra.

I don't think this is an issue with Houdini but I've posted on Davinci Resolve forum with no answers so far.

In the attached file the image on the left is the exr frame seen in Mplay. The one on the right is imported into Davinci Resolve.

The Resolve introduces the starburst ‘artifact’ to the image. And this is happening in its' import stage; Meaning no matter what output file format I choose to export to from Resovle, it passes on these artifacts to the rendered file.

Am I right to assume it's just a simple matter of that both programs, Resovle/MPlay, treating the same file format differently?

I haven't been able to find/work any setting in Resolve that can alter this artifact and I certainly don't know what I can do with Mantra that might alter my image sequences to mitigate what is showing up in Resolve.

I've gone down the road of using exr because from what I've read/reasearched it is a very good choice ( because of layering ) if one intends to do a fair bit of compositing with other software packages.

At the moment my project is not likely to need to go through a compositing stage. As such I've tried a few cin sequences and I do get a nice quality image in resolve with that. I will also be trying a tiff sequence.

But in the long run I would like be able to work with exr to keep my ‘options’ open and learn how to handle situtations like this.

Input is appreciated. Thank you.

Attachments:
Resolve introduces starbursts.jpg (128.1 KB)

User Avatar
Member
2624 posts
Joined: Aug. 2006
Offline
Houdini uses open exr 2.0 http://www.openexr.com/ [openexr.com] Check if Resolve supports it.

Rob
Gone fishing
User Avatar
Member
253 posts
Joined: July 2006
Offline
I've never used resolve but a wild guess would be that it's hinting that those pixels are overbright, above 1.
User Avatar
Member
2035 posts
Joined: Sept. 2015
Offline
Hey Guys,

Thanks for your feedback, just wanted to put out I found a solution in case others might need to know if they are in the same situation.

There was some settings I could apply in Resolve that I missed. They have what are called LUTs ( look up tables ).

I found one that worked for my sitauation, and from a post on their forum one guy seemed to echo what you were saying A-OC:

… pick that color and measure: i bet that is a spike well above the range.

if it is something like 5-10-50, then the sharpen kernel will make lobes visible as the pattern you indicate.

best suggestion i have in mind is to make a dctl or lut that clamp the values at interval. the issue is where we put it: on the front of does not act before the dve is useless and even if it does, then you clip the extra highlight…

I put out the question there of what version of exr Resolve uses as I could not find that info in their documentation but I think it would serve me well once I find out, as I may get a better understanding of this file format when I read the open exr documentation.

So thanks for that suggestion CircusMonkey
  • Quick Links