Pretrained computer vision classifier

Identify stamp image type with one API call.

A pretrained stamp image type classifier that sorts an image into one of 10 categories — what type of stamp it is. Use the stamp image type 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 stamp image type classifier

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

What this stamp image type classifier recognizes

A sample of the 15 labels this pretrained classifier chooses between.

Airmail Stamp
Commemorative Stamp
Definitive Stamp
First Day Cover
Forerunner Stamp
Local Post Stamp
Multiples Stamp
Official Stamp
Perfin Stamp
Postage Stamp

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 stamp image type 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": "Airmail Stamp",
  "labelId": "label_...",
  "confidence": 0.92
}

Under the hood

Model type
Nyckel-trained

Trained on a Nyckel-curated dataset covering 10 stamp image type 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 stamp image type classification

Document Verification

This function can be employed in financial institutions to classify stamped documents such as contracts and agreements. By accurately identifying the type of stamp, organizations can quickly verify document authenticity and streamline approval processes.

Quality Control in Manufacturing

In manufacturing, this image classification function can be utilized to ensure that stamped products meet quality standards. By identifying incorrect or missing stamps, manufacturers can minimize the risk of shipping defective products and enhance overall quality assurance.

Compliance Monitoring

Businesses in regulated industries can use this tool to ensure that all necessary approvals and stampings are in place on documents. By automatically classifying and validating stamp types, organizations can maintain compliance with industry standards and avoid legal issues.

Archive Management

Law firms and public institutions can leverage this function to digitize and organize archived stamped documents. By classifying image types, they can create searchable databases, making it easier to retrieve essential documentation when needed.

Fraud Detection

This function can assist in identifying fraudulent documentation by analyzing stamped images for irregularities or inconsistencies. In sectors like real estate and legal services, it can serve as an additional layer of security against forged or tampered documents.

Inventory Control

Retailers can implement this image classification function to manage inventory that requires stamped approval, such as incoming goods and shipments. By streamlining the identification and verification of stamped paperwork, companies can enhance inventory accuracy and reduce discrepancies.

Customer Feedback Analysis

Companies can use this function to analyze customer-submitted images that contain stamps, such as receipts or warranty documents. By categorizing these images, businesses can gain insights into customer interactions, usage patterns, and improve their offerings based on reliable data.

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 stamp image type 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 stamp image type 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.