Texture Management – BYO Advanced Unsharp Mask tool in RGB & LAB

Series	Texture Management for Digital Video Artists

Part 4 – Building your own Advanced Unsharp mask node trees in LAB & RGB

In the previous Insight in this series, we created a simple Unsharp Mask tool in the node tree. This insight goes deeper into building a node-tree tool for texture work that has bigger functionality than a simple sharpen tool. We will add:

• Clipping protection
• Control the range of data we want to affect
• Add the option to tone down our operation a bit by blending back the original (just like any OFX)

We will explore this in RGB & LAB color models and build this out in a node tree.

The value of building a complex node tree

This Insight creates two fairly complex node trees replicating what you usually find in a plugin. Is this effort worth it? Here’s what I think:

• This series is about teaching concepts. You are learning – not working for a client under a deadline – and complex node-tree-tools are an EXCELLENT way to learn our craft, by going under its hood.
  
• Plugins won’t have every control you may want built into them. So let’s say I’d replace the node tree with a Sharpen OFX – but what if I want to protect against highlight or shadow clipping? What if I want to limit the plugin’s input range? If I understand the plugin at a foundational level, then I may be able to add a few nodes to solve this problem.  
  
  Every professional (or aspiring professional) chooses the level of depth s/he wants to have with their software. The deeper you go, the more you’ll know – and that’s the spirit of this Insight.
  
• Building your tools from nodes is a “gateway-drug” 😉  to heavier stuff – programing your own  DCTLs and Fusion FX can very well be your next step once you’ve gotten a taste of the power under your fingertips.

A note about working in L*a*b

I didn’t mention it in the video – using the L*a*b node tree gives different results in luma and saturation – it also prevents the nasty potential color artifacts/aberrations discussed in the second insight of this series.

Learning goals for this Insight

• How to use the Soft Clip as a clipping protection segment in our pipeline
  
• How simple math (subtracting something than adding it back) must be taken into consideration when building complex node structures
  
• How to add a “Blend with Original” component to your tool
  
• How to select and limit the range of data being affected by our work
  
• Where in the pipeline should you place the Unsharp Mask operation

Additional Downloads

For Premium members, you’ll find two pre-built node trees from this Insight (if you’re a Streaming member, you can upgrade to Premium to gain access).

Download 1: Clipping Protection Unsharp Mask

Remember, this node tree has a Mix Back component (turned off).  The two control nodes for softening are sometimes helpful when combining tools or checking between two options.

Download 2: L*a*b* – L-only Clipping Protection Unsharp Mask

This node tree operates on the L channel of L*a*b without the Mix-Back. You should experiment with placing it at different junctions to see its influence. The Mix-Back usually uses Normal blending mode with the original over the sharpened.

Related Mixing Light Insights

• DCTL Series
• Visual Math Series
• FPE series

Questions and Comments are always welcome

As mentioned above, you are strongly encouraged to explore different ways to apply the Clipping-Protection component in your node tree. I hope you’ll experiment and then come back and discuss it in the comments below. If you find this confusing, also let me know to see if I (or other members) can help clear it up for you.

– Hector

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