Recognize only dots

[Nicksona Marinov]

Hello everybody. I wonder if there is way to train tesseract to effective recogize only SEUENCE of dots in scanned document. For example is there way to recognize these two pictures characteres, which are filled only with dots:

I have tried also with text and a lot of dots, but I found out that the resolution must be super hight for the effective work of tesseract. I`ll be glad if someone can help. If someone think of another way - please to share his opinion, but in that case there is one more condition to observe - on the page there can be not only dots, but text and raster images, so the algorithm should make difference between these three objects, and get only the dots.