Merge Images 🎥🅥🅗🅢

Merge Images joins two image batches end to end: all of group A, then all of group B, out as one batch. It's the reassembly half of VideoHelperSuite's split/merge pair (the other being Split Images) and the tool you use to stitch processed video segments back into a single sequence. Simple job, but with one genuinely useful bit of intelligence - it can reconcile two batches that were rendered at different resolutions, which is exactly the mess you end up with when you process segments separately. It's from Kosinkadink's pack.

The everyday use: you split a clip, sent one half through a heavier upscale, and now the two halves are different sizes. Naively concatenating would fail. Merge Images resizes one group to match the other according to a rule you pick, then joins them.

How it works

It concatenates A followed by B. If the resolutions match, that's the whole story. If they don't, merge_strategy decides the target resolution and the node rescales the mismatched group to fit before joining.

The inputs and outputs that matter

• images_A and images_B - the two batches. Order matters: A comes first in the output.
• merge_strategy - which resolution wins when they differ: match A (use A's size), match B, match smaller (the smaller by area), or match larger.
• scale_method - the resampling filter used if scaling is needed: nearest-exact, bilinear, area, bicubic, or bislerp. Bicubic or bilinear are safe defaults; nearest-exact preserves hard edges.
• crop - disabled stretches to the target aspect ratio, center crops to preserve aspect ratio.

Outputs are IMAGE (the combined batch) and count (its total length).

How to install it

ComfyUI Manager: search ComfyUI-VideoHelperSuite, install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/Kosinkadink/ComfyUI-VideoHelperSuite

then restart. No model downloads.

Common issues & troubleshooting

The seam between the two groups looks stretched. If the batches had different aspect ratios and crop is disabled, the rescaled group gets squished to fit. Set crop to center to keep proportions (at the cost of trimming edges), or make sure both segments were rendered at the same aspect ratio to begin with.

Wrong resolution came out. That's merge_strategy. If you wanted everything at A's size, pick "match A" explicitly rather than relying on which one happened to be larger.

Frames are in the wrong order. Output is always A then B. If your sequence came out reversed, you've got the inputs swapped - feed the earlier segment into images_A.