You can edge detect without using a plug-in: 1. Pull a luma key (node/layer a) and copy it to node/layer b 2. Very slightly blur and erode the key in A 3. Very slightly blur and dilate the key in B 4. Do a matte operator (matte merge or layer blend) and do a diff ( or is it an Or or Union? I forget but you can find the right combo by experimenting) 5. Viola! Edge-detect. Experiment with the matte tool operators by tweaking the blur amounts - maybe no blur at all on step 2, or add blur to the resultant edge matte for another look. The exact methodology will of course vary depending on the grading platform, but the concept is the same.