Frequency Separator

Now Updated with #Simon Devault's brilliant Merge expression, instead of the PSDMerge operation. Thanks Simon

This is a simple script that uses the Frequency Separation technique from Photoshop, in order to split the image to Texture and Lighting passes so you can control each one separately.

You can use the paint node in either the Low frequency image, to do lighting corrections, or paint the High frequency channel to fix Texture details.

Please remember to always have an Alpha channel in you image, or else the PSD Merge node will not function

Usage:

1. Adjust the Gaussian Blur (1) until you dont see the texture detail that you want to correct.

2. Use the RotoPaint2(2) with the Blur Brush to do lighting and chroma corrections without touching the texture

3. You can use any other node after the RotoPaint2(2) and the final Merge(4), to blur sections of the image, like Blurs with mask regions tracked to the object, etc.

4. Use the RotoPaint1(3) with the Clone Brush to correct texture details, like blemishes and spotches.

5. You can also use  tracked surfaces to help with the clone process after the RotoPaint1(3).

Examples:

Blur usage for fixing blemishes and lighting

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Clone Tool usage for removing texture errors