HDR heatmaps and torch mode UHDs

[BrownianMotion]

Originally Posted by Geoff D

I know they don't but I'm not talking about that, i.e. if a display had that capability of simply turning on ST.2084 no matter the source - my ZD9 can do this manually, for example - then you wouldn't need to bother with specific viewers and software and JXR formats or whatever. For me that's the endgame to this whole HDR screencap cluster****, just a one-button push to turn on the HDR EOTF at the display level which would be entirely format agnostic when it comes to the container of the file.

Have you ever tried it though? It would be interesting to see what would happen if you were to view a raw capture of HDR content on your ZD9, and then turn on ST.2084.

[Amano]

Alita SDR has a peak of exactly 100 nits in every shot. That seems to be a bit... artificial. But that's about the movie I guess.

[Geoff D]

Originally Posted by BrownianMotion

Have you ever tried it though? It would be interesting to see what would happen if you were to view a raw capture of HDR content on your ZD9, and then turn on ST.2084.

Of coursh! And in HDR it looks exactly like what the actual video stream the ripped cap was taken from looks like when playing back in HDR.

[Pyoko]

Originally Posted by BrownianMotion

There is software that can capture HDR images that can then be viewed on an HDR display. The photo capture app on the Xbox One X, as well as the Xbox Game Bar app on PC, can both capture HDR images in the JXR format, and they can be viewed in the ways I described above. This is true for video game captures, but I've never tried it with movies. The Xbox One X method will definitely not work for movies, but the Xbox Game Bar on PC might.

I'll check out the Game Bar app when I have the time, thanks for the tip.

Right now I'm capturing raw ST2084-encoded screenshots, except with full levels expansion. If I view them in any regular image viewer and then fake my TV into HDR mode by running some HDR movie in the background then they look properly HDR-y as they should, albeit being 8-bit, as Geoff is saying (wish I had a manual button for HDR on my set too.)

[Pyoko]

Originally Posted by Amano

Alita SDR has a peak of exactly 100 nits in every shot. That seems to be a bit... artificial. But that's about the movie I guess.

It's actually much more uncommon for scenes to go below 100 nits. For a normally lit scene it would take effort to shoot something where no object in it reflected light that broke that barrier. Unless it's a shot in low-light conditions, if it has a peak significantly below 100 then it likely means they intentionally or unintentionally darkened it or compressed the highlights way down in an unnatural manner.

[BrownianMotion]

Originally Posted by Pyoko

I'll check out the Game Bar app when I have the time, thanks for the tip.

Right now I'm capturing raw ST2084-encoded screenshots, except with full levels expansion. If I view them in any regular image viewer and then fake my TV into HDR mode by running some HDR movie in the background then they look properly HDR-y as they should, albeit being 8-bit, as Geoff is saying (wish I had a manual button for HDR on my set too.)

The Xbox Game Bar does indeed work. I just tried it myself. When you capture a screenshot, it gives you both a PNG of the SDR version and a JXR of the HDR version of the image.

You can view them in HDR using an app from the Microsoft Store called HDR + WCG Image Viewer. (EDIT: you can actually view them in HDR using the default Windows photos app, too)

The app lets you create heatmaps, too.

Here are a couple examples from 'Rambo: Last Blood' screenshots:

[tama]

Predator Vision

[Geoff D]

Over here over here

[DR Herbert West]

Anytime

[Amano]

I guess that the UHD Blu-Rays with different masters would offer interesting three-way comparisons (UHD 1, UHD 2, HD).

Braveheart, Cliffhanger, Leon the professional, Arrival, Blade Runner 2048, ...

EDIT: NOT the German Iron Mans though

[Geoff D]

All the German Iron Man discs are good for is a nice set of coasters. Not that the US editions are universally beloved, heh, but ze German ones are even awfuler in their own way.

[Vangeli]

Originally Posted by Amano

I guess that the UHD Blu-Rays with different masters would offer interesting three-way comparisons (UHD 1, UHD 2, HD).

Braveheart, Cliffhanger, Leon the professional, Arrival, Blade Runner 2048, Iron Man 1 + 2 + 3, ...

Please, Blade Runner 2048 was my father. Call me Blade Runner 2049.

[Amano]

Originally Posted by Geoff D

All the German Iron Man discs are good for is a nice set of coasters. Not that the US editions are universally beloved, heh, but ze German ones are even awfuler in their own way.

fix0rd

(was just name-dropping)

[cms382]

Mummy 99 would be interesting to see, average seems okay but daytime desert scenes are pushed within a nanometer of the film’s range.

[Pyoko]

Pretty much SDR with no additional highlight detail, in fact, it's almost reverse HDR. The big nit discrepancy is partly due to the BD being rather dark, frequently with sub-100 nit peaks despite things in the image that should be clipping, but the interesting thing is if you match them in brightness then the highlights actually become brighter on the BD than the UHD.

UHD left, brightened BD right:


Also debuting a new color gamut analysis thingamabob. I've updated the original post if you want to read about it, but tl;dr is Rec709 colors = greyscale, colors beyond that get progressively more saturated/bright. The yellow Wallace HQ and red Vegas desert scenes are very saturated, though I was a bit surprised Purple Joi was almost completely safe inside Rec709.















Album

With a similar highlight roll-off the HDR version would on average be equivalent to the SDR version with peak white at 211 nits (Gamma at 2.40), based on 28 samples. (Min: 171, Max: 240, Median: 210)

[Geoff D]

Re: purple Joi, those kinds of magenta/purple hues are one area of the gamut where there's very little expansion when moving from 709 to P3 (and for blue there's practically none at all), so I'm not surprised that there's so little WCG there. As for it not really being HDR at all, that's Deakins for you.

Great stuff though!! MOAR PLZ

[andreasy969]

Awesome stuff with the gamut heatmap, Pyoko.

[Staying Salty]

[lgans316]

King Kong 2005 would be interesting. Should be torch mode.

BR 2049 - Think there isn't much of HDR due to Roger Deakins not being a fan of it?

[Agent Kay]

Originally Posted by lgans316

King Kong 2005 would be interesting. Should be torch mode.

BR 2049 - Think there isn't much of HDR due to Roger Deakins not being a fan of it?

He is right