Imagelist to Batch

Imagelist to Batch is the inverse of the pack's Imagebatch to List: it takes a list of images and stacks them back into a single IMAGE batch tensor. It's the node at the end of every "split frames, process them individually, put it back together" workflow. But unlike its sibling, it's not a pure structural op - it will quietly resize your images so they can be stacked, and you need to know that before it bites you.

How it works

The node accepts a list of images (it's marked INPUT_IS_LIST). It then takes the first image's dimensions as the target shape and checks every other image against it. Anything that doesn't match gets center-cropped to a square and bicubic-resized to the first image's size before the whole list is concatenated into one batch.

Read that again, because it's the behavior that surprises people. You feed in 12 frames at 512×768 and one odd one at 640×640, and you don't get an error - you get all 12 forced to the first image's geometry, with the odd one center-cropped and stretched to fit. For video frames that all come from the same decoder this never triggers. But if you're building a batch from mixed sources - different crops, different upscale passes, a thumbnail that snuck in - the node will silently harmonize them instead of telling you something's off. That can be exactly what you want (a tolerant stacker) or a subtle quality killer (cropped compositions, resampled detail). Now you know which it is.

The resizing uses center-crop + bicubic resize, the standard "make it fit without distortion" pair. Bicubic is fine for most uses; just don't expect it to be a high-quality upscaler. If the images already match, it's a straight torch.cat - no pixels touched.

When you'd use it

• Closing the loop after per-frame processing (the counterpart to Imagebatch to List).
• Building a batch for nodes that demand one - an image batch encoder, a video encoder, a batch-aware preview.
• Merging images of identical size from several sources.

What's on the node

• images - the input list of IMAGE tensors.
• images output - one IMAGE batch tensor.

Install

cd ComfyUI/custom_nodes
git clone https://github.com/r-vage/ComfyUI-RvTools_v2
# restart ComfyUI

Or via ComfyUI Manager, searching "ComfyUI-RvTools_v2". No models; the pack's deps are the standard torch/numpy/Pillow/opencv-python/pilgram.

The pack caveat

The README flags RvTools v2 as unmaintained and points to ComfyUI_Eclipse as the successor. The original RvTools repo was also yanked from GitHub in early 2025, breaking workflows that referenced it (r/comfyui has the "can anyone re-share it?" thread to prove it). v2 is the renamed, still-loading version. The size-correction behavior, by the way, is a genuinely useful detail to remember - few stackers do this, and knowing it exists is the difference between a working mixed-source batch and a confusing one.