The OCR action isn't atomic and related OCR feedback

[peternlewis]

@Sleepy

I've just discovered that the OCR action isn't atomic. That is, if I have two separate macros running simultaneously and each macro performs an OCR action, the variables in the other macros can end up storing the text from the other macro!

This seems highly improbable, so without a working example, I can't suggest anything.

Obviously, if you use the same (non-local/non-instance) variables in each macro, then they will each mess each other up.

And yes, the action is non-atomic - most every action that takes time in Keyboard Maestro is non-atomic.

@Sleepy

On a related matter, it would be really nice if I could lower the priority of the OCR action.

This is unlikely to happen. The OCR, like the screen search, is a CPU intensive action - if you want to reduce your CPU usage, don't use the action, or don't use the action continuously - put pauses in your macros if you want to use less CPU.

@Sleepy

Also I've noticed that when I try to use the OCR action on a blank area, I tend to get this error: "Warning: Invalid resolution 0 dpi. Using 70 instead."

Yes, this is an error Tesseract reports (more or less all the time), and Keyboard Maestro hides the error from you normally. However, if nothing is returned as matched text, then Keyboard Maestro returns the error response, which includes this message.

@Sleepy

Repeated calls to the OCR action result in the same error. But if I move the image to another part of the screen there's a chance that the OCR action will return the correct words, but generally that trick doesn't help.

Cleaning up the image, in particular thresholding it, seems to improve Tesseract’s accuracy (unfortunately, Keyboard Maestro has no thresholding or other image processing actions, so you'll have to use something else for that).