-
Welcome to the new forums! Please read this first. For known issues we are working to resolve, click here.
GoPro ProTune Flat appears to be a log gamma
- Thread starter Markr041
- Start date
That's why its called Flat.The graph for altering the gamma in GoPro Labs shows the REC709 and Protune gammas.
Uh, if it's a log curve, it should have been called "something log." There is Slog, there is Clog, there is Zlog, there is Vlog. I don't see any camera with a log profile called "Flat" or "XFlat." Flat does not describe the curve. Now we know it's a close to a log gamma.That's why its called Flat.The graph for altering the gamma in GoPro Labs shows the REC709 and Protune gammas.
Jon Stern
Veteran Member
It is a log curve. Why GoPro marketing decided to call it "Flat" many years ago, I don't know.
Full disclosure: I work for GoPro
Full disclosure: I work for GoPro
Maybe Glog sounds weird, flat seems to be referring to how log images tend to look, flat, no contrast.Uh, if it's a log curve, it should have been called "something log." There is Slog, there is Clog, there is Zlog, there is Vlog. I don't see any camera with a log profile called "Flat" or "XFlat." Flat does not describe the curve. Now we know it's a close to a log gamma.That's why its called Flat.The graph for altering the gamma in GoPro Labs shows the REC709 and Protune gammas.
Entropy512
Veteran Member
I really dislike the trend that this started, because "Flat" implies "No curve other than basic Rec709 transfer function" which is *highly* undesirable. Some action camera manufacturers in non-English-speaking countries have sadly misinterpreted "flat" as meaning that...
But yeah, GoPro's ProTune has been known to be log for a long time - https://colour.readthedocs.io/en/v0...fer_functions/gopro.html#log_encoding_Protune was implemented back in 2017 for example:
Loading…
github.com
Now we, or at least, I need a clear explanation what White Balance "Native" is...
Entropy512
Veteran Member
It looks, *roughly* like a nonstandard gamut with a D65 white point from the information I can see.
Won't be able to plug in the primaries into one of my plotting scripts until tonight, but it looks like some form of wide-gamut space, especially since the G primary has a y coordinate in xyY space greater than 1.0. My guess would be that it corresponds to the result of taking the camera's native RGB->XYZ matrix and following it with a chromatic adaptation for the white balance.
Edit: Actually, turns out this is basically a oneliner to plot since it's a predefined colorspace:
colour.plotting.plot_RGB_colourspaces_in_chromaticity_diagram_CIE1931(colourspaces=['ITU-R BT.709','S-Gamut', 'S-Gamut3.Cine', 'Protune Native'])
Can't figure out how to put code snippets into DPR forum psots - probably not possible?
That's a bit of an odd colorspace, IMO way too wide for 8 bits...
I need to look at a few other examples I have at home but that really looks like it might be a native CFA space to me.
--
Context is key. If I have quoted someone else's post when replying, please do not reply to something I say without reading text that I have quoted, and understanding the reason the quote function exists.
Last edited:
Thanks for this.It looks, *roughly* like a nonstandard gamut with a D65 white point from the information I can see.
Won't be able to plug in the primaries into one of my plotting scripts until tonight, but it looks like some form of wide-gamut space, especially since the G primary has a y coordinate in xyY space greater than 1.0. My guess would be that it corresponds to the result of taking the camera's native RGB->XYZ matrix and following it with a chromatic adaptation for the white balance.
Edit: Actually, turns out this is basically a oneliner to plot since it's a predefined colorspace:
colour.plotting.plot_RGB_colourspaces_in_chromaticity_diagram_CIE1931(colourspaces=['ITU-R BT.709','S-Gamut', 'S-Gamut3.Cine', 'Protune Native'])
Can't figure out how to put code snippets into DPR forum psots - probably not possible?
That's a bit of an odd colorspace, IMO way too wide for 8 bits...
I need to look at a few other examples I have at home but that really looks like it might be a native CFA space to me.
--
Context is key. If I have quoted someone else's post when replying, please do not reply to something I say without reading text that I have quoted, and understanding the reason the quote function exists.
Hero 11 has 10bit color now.
Entropy512
Veteran Member
Yeah, but this was designed many years ago when all GoPros had 8-bit recording and 10-bit wasn't anywhere on the product horizon...
Keyboard shortcuts
- f
- Forum