image processing to improve tesseract OCR accuracy

Question

I\'ve been using tesseract to convert documents into text. The quality of the documents ranges wildly, and I\'m looking for tips on what sort of image processing might impr

Answer 1

Adaptive thresholding is important if the lighting is uneven across the image. My preprocessing using GraphicsMagic is mentioned in this post: https://groups.google.com/forum/#!topic/tesseract-ocr/jONGSChLRv4

GraphicsMagic also has the -lat feature for Linear time Adaptive Threshold which I will try soon.

Another method of thresholding using OpenCV is described here: http://docs.opencv.org/trunk/doc/py_tutorials/py_imgproc/py_thresholding/py_thresholding.html