calculate blob angle

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Hello there,

Is it possible to detect the blob angle ? I am currently working on a project to detect letters out of a picture. My letters are on a conveyor belt and a camera takes a picture. In this picture i use blob detection to search for my letter. Because the camera detects lots of other things and since i am only interested in the letter i can easy filter then with filterbyarea. So i get this result

Now assume the letter on the conveyor belt is on an angle greater then 20 degrees. If i use the same program is impossible to detect the letter H. This comes because OCR can only detect letters with an angle of max 20 degrees.

With Quaternion calculation i should be able to calculate this angle, but i can't find any information about this. Is this even possible ?

To make a long story short i want to search the angle X in order to use OCR.

All help is welcome Thanks in advance

Best Regards,

Kenny