HSP file format

I have just read this article[1] and stumbled across this sentence

Photos are saved as HSP files, which can be viewed on HLG-compliant devices.

Does anybody know more about the HSP file format. And are there tools that support this format?


From your link:

HLG Photos are produced as an HSP file. The user can play back these vibrant images on the latest Panasonic HLG-compliant 4KTV via HDMI cable connection or other HLG-compliant devices. It is also ideal for photographers’ photo presentations.

And here some background.

Your quote and your link does’t tell me anything about the HSP file format.

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Sorry! You may have to ask Panasonic.

I’ve tried to ask the customer service, but it was not able to help.

The new cameras are not yet released. Up to now, Panasonic did only HLG video. I am sure more information will be available soon.

Yes, absolutely no information anywhere on the internets about a “HSP” format.

Really though, it’s more about the Hybrid Log-Gamma TRC. This is just a guess, but it’s probably something like, Panasonic wanted to produce still images with this TRC, but couldn’t encode that fact in the metadata, so they took, say, PNG, applied HLG to the image, and saved it with a .hsp filename so their devices know to deal with it as such. Video streams, the original target of HLG, apparently can accommodate such without shenanigns.

I just pushed a rawproc change that adds a ARIB STD-B67 HLG (0.0-1.0, not 0-12) curve to the tone tool, for anyone who’s cloned the repo. Straightforward interpretation from the Wikipedia definition; nice in that you don’t have to do stupid pet tricks to make log behave approaching 0…

Looks interesting.

A digression: for the longest time I have pondered what it would be like if we could change how our cameras recorded and / or encoded the data. I am not an engineer, so I wouldn’t know where to begin.

Panasonic has published more information in this German press release:

In this article you can find this food note:

“HLG (Hybrid Log Gamma)” ist ein internationales Standard (ITU-R BT.2100)-HDR-Format.

Or in English:
“HLG (Hybrid Log Gamma)” is an international standard (ITU-R BT.2100)-HDR-Format.

Wikipedia now tells me that is an video standard:

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That doesn’t tell us anything about HSP. :stuck_out_tongue: The key statement in the Wiki article is

Rec. 2100 has the same color space as Rec. 2020.

which many of us use regularly, so nothing new. I have also been using the HLG curve in several of my recent PlayRaw adventures.

PS I have changed the tag hlrhlg.

I think the “what” is understood, but not the “how”. I’m still unable to find a single HSP file sample…

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Sorry for resurrecting an old thread, but has anyone found any technical information about the HSP file format?

More news on HSP:

and yet not a single sample to be found…


Yup. Why did they do this instead of adding an ICC profile to an HEIF image - that would be at least something standards-compliant and fully capable of encoding 10-bit HLG.

Obviously with a sample we might find that an “HSP” file is just that - a renamed HEIF file.

Sadly, for compatibiity, the only way right now to get HDR/wide-gamut stills displayed on a majority of HDR/wide-gamut capable displays on the market is to encode the still to a 10-bit H.265 video with either HLG or PQ transfer function and Rec.2020 gamut. Fortunately the P frames on a still that isn’t changing encode to very small additions to the file size.