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TESTING

Imageresizer

1. Image Proxy Functionality​

The Open Data Hub provides an image proxy service through the Content API to securely retrieve images hosted on HTTP endpoints and deliver them over HTTPS. This functionality is useful when consuming images from non-secure sources that must be displayed in secure contexts.

The proxy endpoint is:

https://images.opendatahub.com/api/Image/GetImageByUrl

To retrieve an image, pass the source URL as the imageurl parameter.

warning

The Image Proxy only accepts the imageurl parameter. Additional query parameters are not supported unless they are handled by the target server.

1.1. Retrieve an image via proxy​

curl "https://images.opendatahub.com/api/Image/GetImageByUrl?imageurl=http://daten.buergernetz.bz.it/services/weather/graphics/icons/imgsource/wetter/icon_2.png" -o weather-icon.png

This request fetches the image from the given HTTP URL and serves it over HTTPS. You can use this method to embed external images securely in web applications or data visualizations.

2. Image Resizing Service​

The Content API supports dynamic image resizing for images hosted on specific Open Data Hub domains. This feature allows clients to request appropriately sized images without downloading full-resolution assets.

2.1. Supported domains​

Image resizing is available only for images hosted on the following domains:

  • https://tourism.images.opendatahub.com
  • https://images.opendatahub.com
  • https://images.tourism.testingmachine.eu
warning

You cannot resize external images directly. To resize an image from an external source, first retrieve it via the Image Proxy, then host it on a supported domain.

2.2. Resizing parameters​

To resize an image, append either width or height (or both) as query parameters to the image URL.

ParameterTypeRequiredDefaultDescription
widthintegernooriginalDesired width in pixels
heightintegernooriginalDesired height in pixels
curl "https://tourism.images.opendatahub.com/path/to/image.jpg?width=300" -o resized-image.jpg

2.3. Aspect ratio behavior​

  • If you specify only width or only height, the image is scaled proportionally.
  • If you specify both width and height, the image is resized to the exact dimensions, which may result in distortion if the aspect ratio does not match the original.

For example:

https://tourism.images.opendatahub.com/path/to/image.jpg?width=300&height=200

Use proportional values to avoid unintended stretching.

3. Use cases for API users and ingestion creators​

  • API users can leverage the image proxy to securely display weather icons or other HTTP-hosted media in HTTPS applications.
  • Ingestion creators can use the resizing service to generate thumbnails or optimized assets for downstream consumers by referencing hosted images with size constraints.

For more information on consuming data, see Content API Reference.