[After Effects] Cryptomatte edge issue

[verbmeister]

Hello, I have a rendered simple scene in C4D Redshift with cryptomatte AOV (need possibility to change colors in the future). Each object has its own Object ID

Rendered Cryptomatte AOV is colored image with objects

But when I try to manage each object colors (apply 'Cryptomatte' plugin from ProExr) there is an unwanted edge appear

When I try to change Hue its become more visible

Here is compostion layers

Cryptomatte plugin applied on Cryptomatte AOV layer

Here is screenshot than shows 'gradient' pixels of Cryptomatte 'Matte only' function

Could anyone help to resolve this 'edge issue' ?

P.S. For example, there is In UnMult function in Extractor plugin

[SenH]

This is normal. If you think about your RGB beauty (and forget about alpha channels for a minute), you will understand that the edge between the cube and the background is always "contaminated" with both the color of the cube and the BG. There is nothing to unpremultiply in this case, since there are no "clean" RGB values of the BG available.

Cryptomatte is only a generator of masks, it does not solve the edge issue. For light color correction this will not be an issue and you can always fudge with some edge treatment. The clean solution is to render in layers (so you have full RGB information between your FG and BG) or render in deep.