can you provide images without drawn boxes? Zdenko
On Wed, May 14, 2014 at 11:51 PM, Mike <[email protected]> wrote: > Hey Zdenko, thanks for your response! > > Sorry I didn't show any examples. Here are the images: > > > > <https://lh3.googleusercontent.com/-MYoguppN3Yk/U3PfzdqeoaI/AAAAAAAABd8/3Y-3algMNO8/s1600/Screenshot+2014-05-12+00.27.10.png><https://lh6.googleusercontent.com/-J1N9oqe_2YE/U3PfsZWBZhI/AAAAAAAABd0/QdOuZ4QfVt8/s1600/Screenshot+2014-05-12+00.25.54.png> > \<https://lh3.googleusercontent.com/-aPxHy50szMk/U3Pf_xc0WZI/AAAAAAAABeE/6FQeYPl5M_g/s1600/Screenshot+2014-05-12+00.27.59.png> > > <https://lh4.googleusercontent.com/-rBZB-nPgljI/U3PgF-1V3lI/AAAAAAAABeM/Oo1GIsupsLo/s1600/Screenshot+2014-05-12+00.28.08.png> > > > As preprocessing steps I made a few: > 1) DPI is as high as possible (letters are about 30-50 pixel high) > 2) adaptive thresholding is used to remove the most of the noise and it > works quite well > 3) image is framed with white rectangle. > > I didn't do: > 1) deskewing - image is sometimes not perfectly horizontal (but it's just > couple degrees off) > 2) any of morphology filters such as erosion, dilation: in the most cases > it was worsening results > 3) any other image processing (bluring, enhancing, smoothing etc.) > > > Not sure if any other ideas were proposed. What makes me wonder is why > those boxes are well placed some times and the other time placed just plain > awfully? The biggest problem - as you can see - is taking two lines as one. > I used also version without adaptive threshold, but the problem stays the > same. > > > > > W dniu niedziela, 11 maja 2014 17:12:41 UTC+2 użytkownik zdenop napisał: >> >> You did not provide any example image - it does not help ;-). >> Did you try suggested solution on wiki or forum for image improving (it >> was discussed here few times)? >> >> Zdenko >> >> >> On Sat, May 10, 2014 at 7:03 PM, Mike <[email protected]> wrote: >> >>> Hello, >>> >>> I'm working on mobile app which uses tesseract library for OCR. I >>> trained tesseract for my own fonts but results are still very unstable. >>> When I debug results it seems library recognizes letters correctly if boxes >>> are found correctly. However, in many cases they are incorrect. >>> >>> For preprocessing I'm using adaptive thresholding, which deals with >>> pretty well. >>> >>> The common problems with boxes are: >>> 1) detecting one character as two or vice versa >>> 2) detecting very long but narrow boxes covering few lines >>> 3) not detecting boxes >>> >>> How to improve boxes detection? Can I constrain their sizes or ratio? >>> >>> Any suggestions are appreciated. >>> >>> >>> Mike >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "tesseract-ocr" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> >>> Visit this group at http://groups.google.com/group/tesseract-ocr. >>> To view this discussion on the web visit https://groups.google.com/d/ >>> msgid/tesseract-ocr/2599fce4-947e-4093-bf01-f83e0945cfc8% >>> 40googlegroups.com<https://groups.google.com/d/msgid/tesseract-ocr/2599fce4-947e-4093-bf01-f83e0945cfc8%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- > You received this message because you are subscribed to the Google Groups > "tesseract-ocr" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/tesseract-ocr. > To view this discussion on the web visit > https://groups.google.com/d/msgid/tesseract-ocr/9e4d4bb3-326c-4376-ae67-59ea5e377ea0%40googlegroups.com<https://groups.google.com/d/msgid/tesseract-ocr/9e4d4bb3-326c-4376-ae67-59ea5e377ea0%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "tesseract-ocr" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/tesseract-ocr. To view this discussion on the web visit https://groups.google.com/d/msgid/tesseract-ocr/CAJbzG8w1f%3DU1G9RfQ7RMM_rw%2BZsmuwcpdpMJPxJZyam281ZOUw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
