Keyboard Maestro 9 adds support for OCR (Optical Character Recognition) of both the screen or images.
There is a new OCR Screen and OCR Image action, as well as an OCR condition. The OCR actions uses the Tesseract OCR and you can select the desired language - the first time you use a language, Keyboard Maestro will download the trained data file (they vary in size, but are typically a few megabytes).
There is a default macro in the Clipboard Filters macro group called OCR Image that will OCR the system clipboard. You can use this from the action (gear) menu in the Clipboard History Switcher. This can be a great simple way to copy text that is not selectable (such as text from web page images, or from application interfaces or whatever).
The OCR quality tends to be quite good for screen shots, but more varied for scans or pictures.
You can also combine this with the Find Image on Screen action to find something near the text you want to OCR, and then OCR the area relative to that matched image.