An ImageDataProvider implementation is effectively expected to provide image data that is linearly scaled according to the passed zoom. E.g., the data yielded by getImageData(200) should has twice the size as the one returned from getImageData(100). Currently, this assumption is not reflected in the contract of the ImageDataProvider.

The ImageDataProvider contract shall be extended to clarify that implementations need to yield linearly scaled image data. Since the interface has been there for several years and so there may be implementations that do already not fulfill that extended contract, we should make aware of this also by writing a short according news.

So this consists of two tasks to be done together:

• Extend ImageDataProvider contract
• Add release news informing about the clarification of the contract

Since we have the strict check for Windows in place to test whether the provider used in an application fulfill that contract, we may take the chance to extend that strict check to Linux and MacOS as well, so that we can mention it in the ImageDataProvider documentation and the news to enable developers on all platform to more easily validate whether they fulfill this contract. I am not sure about this last point, so please comment on what you think about it.