I’m trying to use tesseract from command line to run OCR on the content of an opened window. In particular I’m willing to read the text typed into a current opened Notepad window.
I’ve read the documentation and the wiki here: http://code.google.com/p/tesseract-ocr/w/list
but I didn’t find anything that helped me in this project, further more I’ve also searched here for similar questions ( there are many about OCR) but nothing seems to work/ be applicable in my case.
Is it feasible?
I’m mainly a PHP coder (coding just for fun) and have no experience in non-web languages.
Thanks in advance.
Tesseract is designed to take a TIFF image as input and know nothing about the Windows or screen Device Contexts. So you would need to add code to locate the windows handle for the Notepad window , perform a screen capture and clip the window based on the current window size reported by Windows and save the resulting image to a file. This image will most likely be black and white which will make it easier to OCR as I suspect Tesseract 2.0 only works with B/W Images. The next problem will be Tesseract gving poor results due to the low DPI (resolution) of the source image.
To evaluate the suitability of your approach I would perform some manual tests by opening Notepad, taking screenshots, opening the screenshots in MSPaint, clipping the text you want to OCR, save the clipped image to a TIFF or BMP and send this file to Tesseract. This could save you a lot of time and effort if the results are not as good as you need or expect.