The DPI measure is confusing for Tesseract's OCR, forget about it. The big thing is within-image font's x-height, measured in pixels. Tesseract, trained with ordinary fonts, proved good with fonts of 12-64 pixel height. If you have bigger characters, scale them down. If you have a font that's bold, use morphology and erode characters after binarization. Experiment. Removing "greyness" won't help as it's not a generic way of getting rid of uneven illumination; you need to use more sophisticated algorithms. Just using Photoshop won't let you achieve much.
Warm regards, Dmitri Silaev www.CustomOCR.com On Fri, Aug 19, 2011 at 8:18 PM, Andriy Malovanyy <[email protected]> wrote: > To Zdenko: > I think I have 3.0 version installed, so maybe I should reinstall the > new version and try it. Thanks for the description of psm. Did you try > to recognize other unedited images which I attached to > the first post?? > > To Rob: > Initially I had 640x480 image with 72dpi with number occupying almost > all the image. What I did is just opened the image in Photoshop, went > to size of image menu, changed the resolution to 300 dpi (image > increased in size) and set the image size back to 640x480. So, with > that I got 640x480 image with 300dpi resolution. > > On 19 Aug, 17:56, Robert Komar <[email protected]> wrote: >> On Fri, 19 Aug 2011, Andriy Malovanyy wrote: >> > To sriranga: >> > I tried changing dpi (check the previous post). It doesnt work. >> >> Did you rescale the image from 72 dpi to 300 dpi, or just change >> the tag on the original image to say 300 dpi? The latter won't work. >> Tesseract seems to be tuned to work best for scans at 300 dpi >> (although I've often successfully used 600 dpi). Scans done at >> 72 dpi usually get very poor results from tesseract. >> >> Cheers, >> Rob Komar > > -- > You received this message because you are subscribed to the Google > Groups "tesseract-ocr" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/tesseract-ocr?hl=en > -- You received this message because you are subscribed to the Google Groups "tesseract-ocr" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/tesseract-ocr?hl=en
