title: image processing to improve tesseract OCR accuracy
body: <p>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 improve the results. I've noticed that text that is highly pixellated - for example that generated by fax machines - is especially difficult for tesseract to process - presumably all those jagged edges to the characters confound the shape-recognition algorithms. </p>
  
  <p>What sort of image processing techniques would improve the accuracy? I've been using a Gaussian blur to smooth out the pixellated images and seen some small improvement, but I'm hoping that there is a more specific technique that would yield better results. Say a filter that was tuned to black and white images, which would smooth out irregular edges, followed by a filter which would increase the contrast to make the characters more distinct.</p>
  
  <p>Any general tips for someone who is a novice at image processing? </p>