OpenCV completeSymm_1

completeSymm_1 is completeSymm_0, again. Same function (cv2.completeSymm), same inputs, same in-place behavior, same output. The opencv-comfyui pack generates a node per overload in OpenCV's type stubs and numbers the collisions, and for this function the two overloads compiled to identical implementations. So everything on the completeSymm_0 page applies here verbatim - pick one node, forget the other exists.

The short version

cv2.completeSymm(m, lowerToUpper) forces a square matrix to be symmetric by copying one triangle onto the other:

• m (NPARRAY) - must be square, or you get (-215:Assertion failed) m.rows == m.cols.
• lowerToUpper (BOOLEAN) - true copies lower → upper, false copies upper → lower.
• Output: nparray - the same matrix, now symmetric. It mutates in place.

It's a math utility, not an image filter. Realistic ComfyUI use: symmetrizing a covariance, correlation, Gram, or similarity matrix you computed from features so downstream eigendecompositions behave. That's a niche within a niche, and it's fine that it's niche - it's one of ~635 auto-generated nodes, and this is one of the "only reach for it when the math demands it" ones.

Install

Identical to the rest of the pack:

cd ComfyUI/custom_nodes
git clone https://github.com/geroldmeisinger/opencv-comfyui

or ComfyUI Manager → search "opencv-comfyui". Requires opencv-python-contrib. Watch for the Cannot import name 'guidedFilter' from 'cv2.ximgproc' conflict if two OpenCV installs collide in your environment. And don't try to render the output through Nparrays2Image - it's a matrix, not a picture, and you'll get an unhappy error message instead of a preview.