highgui missing in 3.0 release
When frameworks such as Open CV break interfaces they ruin upgrade paths, they ruin the countless tutorials on how to use OpenCV because now they won't work with the latest and greatest releases. Why not follow the Java Convention of Deprecation (keep it around, but discourage it). In the documentation show the new way but do not omit it. This frustrates me to no end, and is the very anti-adoption/usage pattern of Open Source Software systems. In one hand, the architects are trying to get people to adopt their "SYSTEM", but in the other hand they alienate everyone by re-arranging the furniture on a blind person. Only they know what they have done and it takes a while for documentation and tutorials to be generated. It's very frustrating.
It is now in vidoeio and imgcodecs