tesseract OCR have a command line interface, which allow us to recognize text from images with some parameters.
Input argumetns are imagename (path to image) outputbase (name of recognized text) and -psm pagesegmode parameters.
pagesegmode values are: 0 = Orientation and script detection (OSD) only. 1 = Automatic page segmentation with OSD. 2 = Automatic page segmentation, but no OSD, or OCR 3 = Fully automatic page segmentation, but no OSD. (Default) 4 = Assume a single column of text of variable sizes. 5 = Assume a single uniform block of vertically aligned text. 6 = Assume a single uniform block of text. 7 = Treat the image as a single text line. 8 = Treat the image as a single word. 9 = Treat the image as a single word in a circle. 10 = Treat the image as a single character. -l lang and/or -psm pagesegmode must occur before anyconfigfile.
But can it library write positions and sizes of recognized text blocks to the specific file or it is an internal information?
Tesseract 3.0x supports a "hocr" command option, which produces a HTML-format output file consisting of recognized words and their coordinates. It does not have size/font info, though.