Player with Ball Detection
Detect which player is currently holding the basketball in NBA game footage. The base model produces excessive false positives, mistaking many players for having the ball. After RL fine-tuning, Moondream learns that only one player can have the ball, improving its F1 score from 28% to 79%, compared to GPT-5.4's 53%.
F1
| Method | RL |
| Steps | 60 |
| Training time | 54 min |
| Cost | $16.89 |
See it in action
Switch between benchmark examples to compare the base model against the fine-tuned model on the same task.
Prompt
player with the ball
Base Moondream 3 Preview
mIoU 0.085
Fine-tuned Moondream 3 Preview
mIoU 0.783+0.698
Perfection in 3 steps
What is fine-tuning?
Moondream starts as a general model trained on broad, public information. Fine-tuning makes it great at one specific task by teaching it the products, documents, categories, or internal information that matter to your business.
Who is this for?
This is for teams putting vision AI into production. If you already know the task and need the model to master that job, fine-tuning is how you get there. It is built for teams that need frontier performance at real-time speed.
See the code
Fine-tuning is just a small API loop: format your data, call `train_step`, and the model updates as you go.
import moondream as md
# Create fine-tune
ft = md.ft(
api_key="your-api-key",
name="player with ball detection",
rank=8,
)
# Hidden boilerplate and data code
requests = (
(
example,
{
"skill": "detect",
"image": example["image"],
"object": "player with the ball?",
"num_rollouts": 4,
},
)
for example in training_data
)
for context, response in ft.rollout_stream(requests):
rewards = compute_rewards(context, response)
ft.train_step([{
"mode": "rl",
"request": response["request"],
"rollouts": response["rollouts"],
"rewards": rewards,
}])Frequently asked questions
Ready to take Moondream to production?
Need help? We'll build it for you.
We can help define the task, prepare the data, run training, validate results, and hand off a model your team can use.