(VLMs) answer questions about images. Adding capability usually means adding parameters, which costs more computing per image. V-LUMEN adds a separate lookup table, like a dictionary of visual facts, that the model queries.
For each image patch, the model assigns a code from a fixed dictionary, then uses a hash (a fast way to find a slot) based on that code, the patch's location, and the question, to fetch relevant entries. The fetched entries are merged into the model's processing while the model's existing weights stay frozen (unchanged).
On five reasoning benchmarks, this improved a model with 2 billion parameters, and transferred to new image types without retraining. It matched the accuracy of fine-tuned adapters (small extra modules) while using less per-image compute, because the extra knowledge lives in storage, not in computation.
