Predict the total vision-token count for a tiled high-resolution image
A VLM uses AnyRes tiling. A high-resolution image is split into a 3x3 grid of tiles, and one additional downscaled global view of the whole image is added. The vision encoder emits 256 tokens for each tile and 256 tokens for the global view. How many vision tokens does this single image contribute to the LLM's context?
A 3x3 grid is 9 tiles plus 1 global view, so 10 encoder passes at 256 tokens each gives 2,560 vision tokens for one image.
Imagine cutting a big poster into a 3-by-3 grid of squares, then also keeping one shrunk-down copy of the whole poster. Now count how many pieces a reader has to look at: nine squares plus one whole-poster thumbnail makes ten pieces. The reader writes the same number of notes, 256, for every single piece. So you just multiply: ten pieces times 256 notes each equals 2,560 notes for this one poster. The mistake people make is forgetting that 3-by-3 means nine pieces, not three, or forgetting the extra thumbnail. Count the pieces carefully, multiply, done.
Detailed answer & concept explanation~6 min readEverything you need to truly understand this topic: intuition, mechanics, step by step explanation, code, formulas, and worked example. Click to expand.
Everything you need to truly understand this topic: intuition, mechanics, step by step explanation, code, formulas, and worked example. Click to expand.
Everything you need to truly understand this topic: intuition, mechanics, step by step explanation, code, formulas, and worked example.
Everything important, quickly.
Count 9 tiles plus 1 global view, multiply by the 256-token block to get 2,560, then explain how the count scales with tile grid and why those tokens dominate prefill and KV-cache cost.
Real products, models, and research that use this idea.
- LLaVA-NeXT AnyRes splits a high-resolution image into a grid of tiles plus a global view, each tile emitting its own block of vision tokens just like this scenario.
- OpenAI GPT-5.5 high-detail images are priced as a base block plus per-tile blocks, so a large image lands in the thousands of tokens.
- Qwen3-VL dynamic resolution scales the number of visual tokens with input size, so a dense full-page scan costs far more tokens than a thumbnail.
What an interviewer would ask next. Try answering before peeking at the approach.
QWhat is the token count if the grid grows to 4x4 with the same global view and per-tile block?
QWhy does token count under tiling scale roughly with the square of resolution?
Don't say thisRed flags and common mistakes that signal junior thinking. Click to expand.
Red flags and common mistakes that signal junior thinking. Click to expand.
Reading 3x3 as 3 or 6 tiles instead of 9, or forgetting the global view adds one more block. Both undercount the total.
The night-before-the-interview bullets. Scan these on the way to the call.
Primary sources. Skim if you want the original framing.
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