Pretrained computer vision classifier

Identify stadium spectators count with one API call.

A pretrained stadium spectators count classifier that sorts an image into one of 10 categories — the number of spectators in a stadium. Use the stadium spectators count API immediately, no training required, then adapt it to your own data when you need more.

Pretrained · Nyckel-trained 10 labels out of the box Image input

Try the stadium spectators count classifier

Drop in a photo and get the prediction back. No signup, no setup.

What this stadium spectators count classifier recognizes

A sample of the 10 labels this pretrained classifier chooses between.

1-5
1001-5000
101-200
11-20
201-500
21-50
5000+
501-1000
51-100
6-10

Need a label that isn't here? Clone the classifier into your Nyckel console and edit the label set to fit your data.

Call the stadium spectators count API

Once you've added this classifier to your console, you get your own copy of it behind your own endpoint. Invoke it with any HTTP client:

curl

curl -X POST "https://www.nyckel.com/v1/functions/YOUR_FUNCTION_ID/invoke" \
  -H "Authorization: Bearer $NYCKEL_ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"data": "https://example.com/photo.jpg"}'

Python

import requests

# Get an access token: https://www.nyckel.com/docs/api/overview/authentication/
token = "YOUR_ACCESS_TOKEN"

response = requests.post(
    "https://www.nyckel.com/v1/functions/YOUR_FUNCTION_ID/invoke",
    headers={"Authorization": "Bearer " + token},
    json={"data": "https://example.com/photo.jpg"},
)
print(response.json())

Example response

{
  "labelName": "1-5",
  "labelId": "label_...",
  "confidence": 0.92
}

Under the hood

Model type
Nyckel-trained

Trained on a Nyckel-curated dataset covering 10 stadium spectators count categories, served on Nyckel's own infrastructure — your image stays on Nyckel.

Input
Image

Send an image URL or file to the invoke endpoint; the response is a label with a confidence score.

Make it yours
Adaptable

Clone it, then correct predictions and add your own samples in the console — Nyckel retrains automatically, turning this into a custom model tuned to your data.

More than a demo: this page is one of thousands of pretrained functions on Nyckel, an ML classification platform. You can invoke classifiers by API, review predictions, correct labels, collect samples from production traffic, and promote any pretrained function to a private custom model — without changing your integration.

Where teams use stadium spectators count classification

Event Safety Management

The false image classification function can be utilized to assess crowd density in stadiums during events. By identifying the number of spectators, security personnel can ensure that occupancy limits are not exceeded and manage crowd movements for safety.

Ticket Sales Analysis

Sports and entertainment organizations can leverage the function to track actual attendance figures and compare them to ticket sales. This can help identify discrepancies, assess ticket pricing strategies, and optimize future marketing efforts.

Fan Engagement Strategies

By analyzing crowd size and demographics through this classification function, teams can tailor fan engagement strategies. Understanding which demographics attend events allows for targeted promotions and improved fan experiences.

Emergency Response Planning

In the event of a crisis, this function can provide real-time data on the number of spectators present. Emergency teams can plan and allocate resources effectively, ensuring swift and efficient response measures.

Stadium Operations Optimization

Stadium managers can use the function to monitor spectator counts and adjust operational procedures accordingly. This can improve concessions inventory management, restroom facilities, and general seat availability, enhancing overall visitor experience.

Sponsorship and Advertising Metrics

Advertisers and sponsors can benefit from accurate spectator counts to assess the reach and impact of their campaigns. This data allows for better arguments in negotiations for sponsorship deals based on actual audience exposure.

Health and Safety Compliance

With changing regulations regarding public gatherings, the function helps stadiums remain compliant by monitoring and reporting real-time audience numbers. This ensures adherence to health guidelines, such as social distancing requirements during health crises.

Common questions

What's the difference between a zero-shot and a Nyckel-trained classifier?

A zero-shot classifier uses a large foundation model's general knowledge to pick between your labels — no task-specific training, so new or edited labels work immediately. A Nyckel-trained classifier has been trained on labeled examples and runs on Nyckel's own infrastructure, which typically makes it faster, cheaper per call, and more accurate on data that resembles its training set. The "Under the hood" section on this page shows which kind this classifier is, and any classifier can be adapted into a trained one by adding your own examples.

How do I know whether this will work for my application?

Honestly: we can't know in advance — it depends on your data stream and how closely it resembles what this classifier has seen. The reliable way to find out is to measure it on your own data: start invoking the classifier with real traffic, or upload and annotate a set of images in the console — make sure they look like your production data, not idealized examples. Nyckel's evaluation metrics then show you exactly how it performs on that data before you rely on it.

What happens when it makes a mistake?

No classifier is perfect, so Nyckel is built around the correction loop: invokes can be captured for review, you confirm or correct predictions in the console, and corrections become training data. Over time the model adapts to your data distribution — accuracy on your traffic improves with use rather than staying fixed.

Do I need training data to get started?

No. This stadium spectators count classifier works out of the box — clone it into your console and you'll have your own API endpoint in under a minute. Training data only enters the picture when you want to adapt it: your corrected predictions and uploaded samples improve the model, and you can also edit the label set to match your needs.

What does it cost to try?

Trying the classifier on this page is free with no signup. Cloning it requires a free account, and the free tier covers your first API calls each month — see nyckel.com/pricing for current limits and paid tiers.

Ready to classify stadium spectators count at scale?

Add this pretrained classifier to your Nyckel console — you'll get a live API endpoint in under a minute, and a path to a custom model when you need one.