HSV colourspace round trip

Is there any current way to separate out an image to HSV and round trip? Separate and combine are great but only HSL is available - similar but not the same.

Hi Drew,

Please file a request on the Flame Feedback Portal for the designers to investigate.

Thanks Grant! I’ve lodged a request.

So I googled the differences between these and I’m curious what the use cases are?

I love a good channel separation trick.

5 Likes

I came across this as I’m looking to create a shadow plate/pass. Using HSL doesn’t seem to give back the same results

3 Likes

this looks cool! thanks for the link.

I know! Would be great to use this technique in Flame

1 Like

It’s pretty easy to convert to HSV in a matchbox, I’ve made one here which also does a bunch of other colourspaces that split brightness/chroma in various ways, including new kid on the block Oklab: Shader: Ls_Colourspace

I did think about adding ACES and Arri/Red etc camera colourspaces to it but Color Mgmt already does a great job of all those and I don’t want to get into a situation where this shader doesn’t match the standard Flame transforms… I already noticed that the ACES/CIE-XYZ .ctf uses a slightly different matrix to what Nuke does, I’m guessing because of better chromatic adaptation :hushed:

2 Likes

Also has anyone else played with the shadow plate technique from the video above? I’d never heard of the repeated luma key/grade in HSV stack thing before, I feel like I don’t fully understand why it works!? I replicated what it does in a matchbox here: Shader: Ls_Shadowplate, quick demo here: Shadowplate demo - YouTube

It pulls the luma key from all channels of the HSV image, which is unexpected because that means it depends on hue and saturation as well… definitely works in some situations but I feel like it reveals noise/compression artifacts easily :thinking: Using just a regular luma key (or only using the V channel) makes things turn into flat solid colours whereas this definitely preserves some texture somehow - pretty mysterious, wonder if it was just developed by trial and error…

5 Likes

Lewis thank you so much!!! Amazing! I figured it wouldn’t be successful in every scenario but definitely a great technique to have in the toolset. I will give it a go ASASP

Really appreciate you taking the time for this!

1 Like