Full Dynamic Range HDRi Problems

[HISEROD]

Hey,

     I've been trying my best to create HDRi's in hugin for about a month now, and I still have many problems. For one whenever I blend in the far under exposed images I get fireflies in the blended panorama, and whenever I remove the unnecessary ones I get odd black gradients.

     fyi my nadir shots are not exposure bracketed. (not sure if this is the cause of some problems or not)

     Also I should mention that I have little experience with hugin.

[Brian Innes]

I'm not sure I understand what you mean by fireflies and odd black gradients?

Can you share example images showing these issues? Or even share a sample hugin .pto file along with source images?

Regards,

Brian.

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[Greg 'groggy' Lehey]

On Saturday, 9 September 2017 at 9:38:16 -0700, HISEROD wrote:
> Hey,
>
> I've been trying my best to create HDRi's in hugin for about a month
> now, and I still have many problems. For one whenever I blend in the far
> under exposed images I get fireflies in the blended panorama, and whenever
> I remove the unnecessary ones I get odd black gradients.

It would be interesting to see how you do this. I create HDR images
on a regular basis with a script that you can find at
http://www.lemis.com/grog/src/HDR

It's relatively long, but the payload is at the end:

nice align_image_stack -a $TMP $FILES
nice enfuse -o $RESULT $TMP*

It should work essentially "as is" on most systems, but not Microsoft.

> fyi my nadir shots are not exposure bracketed. (not sure if
> this is the cause of some problems or not)

You mean you take a single image for the nadir? That shouldn't be a
problem.

Greg
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[HISEROD]

 @Brianlnnes: Fireflies are very bright pixels in seemingly random places commonly seen in ray traced renders, you can see them and the gradients in the attached file.

@Groogle: I'm not certain what that script is for. But I am using Microsoft, so I guess it doesn't matter?

[Greg 'groggy' Lehey]

On Sunday, 10 September 2017 at 18:13:17 -0700, HISEROD wrote:
> @Brianlnnes: Fireflies are very bright pixels in seemingly random places
> commonly seen in ray traced renders, you can see them and the gradients in
> the attached file.

Please don't post images here. It also doesn't help: what people
would want to see are the input images and a description of how you
processed them, possibly including the .pto file.

> @Groogle: I'm not certain what that script is for. But I am using
> Microsoft, so I guess it doesn't matter?

Step back a bit, and you'll get more out of this exchange. I don't
understand your use of @ signs, but they're out of place here, and
you've lost your context. Let's try again:

> On Sunday, 10 September 2017 at 9:55:42 +1000, Greg 'groggy' Lehey wrote:
>> On Saturday, 9 September 2017 at 9:38:16 -0700, HISEROD wrote:
>>>
>>> I've been trying my best to create HDRi's in hugin for about a month
>>> now, and I still have many problems. For one whenever I blend in the far
>>> under exposed images I get fireflies in the blended panorama, and whenever
>>> I remove the unnecessary ones I get odd black gradients.
>>
>> It would be interesting to see how you do this.

You seem to have missed this.

>> I create HDR images on a regular basis with a script that you can
>> find at http://www.lemis.com/grog/src/HDR
>>
>> It's relatively long, but the payload is at the end:
>>
>> nice align_image_stack -a $TMP $FILES
>> nice enfuse -o $RESULT $TMP*
>>
>> It should work essentially "as is" on most systems, but not Microsoft.
>

> I'm not certain what that script is for.

As I said,

>> I create HDR images on a regular basis with a script that you can
>> find at http://www.lemis.com/grog/src/HDR

So it's for creating HDR images.

> But I am using Microsoft, so I guess it doesn't matter?

No, it means that the script won't work for you. You will have more
work ahead of you. Assuming that you don't write Microsoft scripts on
a regular basis, the easiest would be just to type in the commands.
Assuming you have three images view-1-1.jpeg, view-1-3.jpeg and
view-1-3.jpeg (what gets called FILES in the script), and you want to
create an output file view-1.jpeg (called RESULT in the script), you
could write:

nice align_image_stack -a view-1-tmp view-1-*.jpeg
nice enfuse -o view-1.jpeg view-1-tmp*

You'll then need to remove the -tmp files. Of course, if you can find
a way to write a script, this will greatly simplify your life.

[HISEROD]

Ok then,

     I'm confused. Where am I supposed to put these commands?

     I've been following a tutorial by Greg Zaal on HDRi's at adaptivesamples.com. (tutorial) Except I'm using (or at least trying to use) Hugin instead of PTgui.

[Markku Kolkka]

HISEROD kirjoitti 12.9.2017 klo 5.30:
> Ok then,
> I'm confused. Where am I supposed to put these commands?

The script/commands posted by Greg are for creating exposure fused LDR
images which are not the "full dynamic range HDRi" images you want.

> I've been following a tutorial by Greg Zaal on HDRi's at
> adaptivesamples.com. (tutorial)

> <http://adaptivesamples.com/2016/03/16/make-your-own-hdri/> Except I'm

> using (or at least trying to use) Hugin instead of PTgui.

First, switch the Hugin GUI to Expert mode (Interface->Expert). Next,
import all your image files in the Photos tab. Hugin should detect
bracketed stacks and offer to link them automatically, so there's no
separate command for linking HDR exposures like in PTGui. Create control
points, optimize geometry and optimize photometry for high dynamic
range. On Stitcher tab choose High dynamic range as Panorama Output, set
other options and press "Stitch!".

[HISEROD]

Ok,

     That's about what I've been doing, but I am getting noise from the less exposed pictures.

In the image I posted earlier its not as bad because I removed some of the lower exposures, but then there's those black gradients.