OpenCV resizeWindow_0

Let's be honest with you: resizeWindow_0 is one of those nodes you should probably not use. It wraps cv2.resizeWindow(winname, width, height), which is an OpenCV HighGUI desktop function - it resizes a window that namedWindow/imshow created on a real display. ComfyUI is not that. It's a headless node server running a web UI; there is no native OpenCV window to resize, and this function does essentially nothing useful in that context.

It exists because opencv-comfyui (geroldmeisinger/opencv-comfyui) auto-generates a node for every top-level standalone OpenCV function it finds in the type stubs, and this is one of the functions that plainly makes no sense in ComfyUI. The author's own todo list includes "blacklist functions which don't make sense in ComfyUI (like return type None)" - and look at the outputs: this node declares a single output of type None named unknown. There is nothing to wire. That's the tell.

The inputs, for completeness: winname (a STRING, the window name), width and height (the target window size). If you really wanted to see something, you'd pair it with the pack's other window nodes (namedWindow, imshow, resizeWindow) - but even then, on a server ComfyUI there's no desktop window to look at, and on a local box the browser-based preview is what you actually want.

Installing it

If you're installing the pack anyway (for its genuinely useful nodes like resize, cvtColor, rectangle), the install is the same:

ComfyUI Manager (search "opencv-comfyui"), or:

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

restart, then confirm OpenCV:

pip install opencv-contrib-python

The practical take

Don't reach for this node to preview or view images - use ComfyUI's Preview Image or Save Image for that. This one is a leftover from the pack's "wrap everything" philosophy, and the honest advice is to ignore it, same as the other None-returning HighGUI stragglers. The good news: the same pack gives you the resize you actually want in resize_0, which resizes images, not phantom windows. Use that one.