MobileSAM

MobileSAM replaces SAM's ViT-H image encoder with a distilled TinyViT encoder, so the same promptable point-and-box workflow runs on lighter hardware. LibreYOLO carries a native port of it through a dedicated LibreSAM factory, separate from the LibreYOLO() detector factory.

Tasks
instance segmentation
Sizes
tiny at 1024 px
Install
pip install libreyolo
Support tier
Sibling tier, since v. A separate product surface with its own factory and contract.
Upstream
MobileSAM by Kyung Hee University, Apache-2.0. Paper, source
Licenses
Code Apache-2.0, weights Apache-2.0. Commercial use

Install

MobileSAM needs the sam extra: LibreYOLO's own weight download still goes through transformers' Hugging Face snapshot tooling, even though inference runs on a native, non-transformers decoder.

bash
pip install "libreyolo[sam]"

Predict

LibreSAM(...) (or the family-specific LibreMobileSAM(...)) is a separate entry point from LibreYOLO(...): it returns a promptable segmenter rather than a detector, because a forward pass here is meaningless without a spatial prompt. There is no libreyolo predict CLI command for this family; use the Python API.

Point and box prompts
from libreyolo import LibreSAM, SAMPLE_IMAGE # MobileSAM has a single size, "tiny", so no other alias is needed.model = LibreSAM("mobilesam") # A point prompt: [x, y] in pixel coordinates, label 1 = foreground.result = model.predict(SAMPLE_IMAGE, points=[640, 420], labels=[1])print(result.masks.xy)      # polygon per maskprint(result.boxes.xyxy)    # tight box derived from the mask # A box prompt instead of a point.result = model.predict(SAMPLE_IMAGE, bboxes=[300, 200, 900, 700]) # No prompt at all segments the whole image (a simplified automatic# mask generator, not the exhaustive reference one).result = model.predict(SAMPLE_IMAGE)
Encode once, prompt many
from libreyolo import LibreMobileSAM, SAMPLE_IMAGE model = LibreMobileSAM() # The image encoder is the expensive part. set_image() runs it once;# every predict() call after that reuses the cached embedding.model.set_image(SAMPLE_IMAGE)a = model.predict(points=[640, 420], labels=[1])b = model.predict(bboxes=[300, 200, 900, 700])model.reset_image()

A point prompt accepts [x, y] for one object, [[x, y], ...] for several, or numpy arrays; labels marks each point 1 (foreground) or 0 (background) and defaults to all foreground. A box prompt takes [x1, y1, x2, y2] or a list of boxes, one mask per box. Omitting both prompts segments the whole image by prompting a dense grid and keeping the confident, non-overlapping masks; this "segment everything" mode is simplified against the reference automatic mask generator and can under-segment crowded scenes, so a real point or box prompt is the precise path. conf filters by predicted mask quality (IoU), not a detection confidence: pass 0.0 to keep every candidate. multimask=True returns all three of SAM's whole-versus-part ambiguity masks per prompt instead of the single best one. device= moves the model and, if a set_image() session is active, its cached embedding. Every mask carries class id 0, named "object", since a promptable mask has no fixed class set. train(), val(), export() and track() all raise NotImplementedError for this family: MobileSAM is predict-only in LibreYOLO. See prediction for source types.

Variants

One size, tiny, at a fixed 1024 px input: MobileSAM ships a single TinyViT encoder rather than the base/large/huge ladder SAM-1 offers.

Checkpoints

Every published weight file for this family.

FileInput (px)Weights license
Instance segmentation
LibreMobileSAM.ptapache-2.0

Every file above exists in the LibreYOLO org today and downloads on first use.

Licensing

Check the license on the Hugging Face repository of the specific weights you download. Every checkpoint in the LibreYOLO org carries one, and they are not always the same across a family. That repository is the authoritative source; the summary below describes what applied when this page was last verified.

This is a description of the licenses involved, not legal advice. If the answer matters commercially, read the licenses yourself and take your own counsel.

Original work
MobileSAM, Kyung Hee University
Upstream license
Apache-2.0
LibreYOLO code
MIT
Weights
Apache-2.0, republished at huggingface.co/LibreYOLO
Interpretation
Apache-2.0 is a permissive license, so this code and these weights can be used in commercial and closed-source products. It asks you to keep the license text and attribution notices with any copy you redistribute, and it grants a patent license. LibreYOLO carries a native port of the TinyViT image encoder, prompt encoder, two-way transformer and mask decoder rather than vendoring upstream files unmodified, checked for bit-exact parity against the original Apache-2.0 implementation, with a NOTICE recording that provenance. The converted checkpoint is hosted as LibreMobileSAM.pt on the LibreYOLO Hugging Face org, tagged Apache-2.0 there as well.

Citation

@article{mobile_sam,
  title={Faster Segment Anything: Towards Lightweight SAM for Mobile Applications},
  author={Zhang, Chaoning and Han, Dongshen and Qiao, Yu and Kim, Jung Uk and Bae, Sung-Ho and Lee, Seungkyu and Hong, Choong Seon},
  journal={arXiv preprint arXiv:2306.14289},
  year={2023}
}

Copied from the authors' citation block at github.com/ChaoningZhang/MobileSAM#bibtex-of-our-mobilesam.

Verified against LibreYOLO v1.5.0. Support tables, checkpoints and benchmark numbers on this page are generated from the released library and the published weights, not written by hand.