ggml-org/llama.cpp b11774

on GitHub

mtmd : lfm2 tiles and layout match transformers (#30261)

• mtmd : lfm2 tiles stretch the image to the grid

Lfm2VlImageProcessor.crop_image_to_patches resizes the image straight to
(512 * rows, 512 * cols) before it cuts the tiles. llama.cpp kept the aspect
ratio and added black bars for LFM2 (only d1-omni stretched), so the tiles of
d1-3B and every LFM2-VL / LFM2.5-VL model differed from transformers unless
the image had the aspect ratio of the grid. With PAD_NONE the tiles are the
same as in transformers.

• mtmd : lfm2 layout with Python rounding in double precision

Lfm2VlImageProcessor.smart_resize rounds with Python's round (half to even)
and computes beta and the tile grid aspect ratio in double. llama.cpp used
std::round and float, so 31926 of the 16.7M sizes in [1,4096]^2 got another
thumbnail size or grid than transformers (and d1-omni vision.py), e.g.
400x600 -> 416x608 instead of 384x608 and 720x1600 -> 2x5 tiles instead of
2x4. The lfm2 smart resize and grid choice now follow the Python code and
match it on every size of that range.

• fix

Co-authored-by: Xuan Son Nguyen son@huggingface.co