Regarding open and close operators: First, look at http://tpgit.github.io/Leptonica/morph_8c_source.html pixDilate pixErode and for a real example see http://www.imagemagick.org/Usage/morphology/#erode I think that this code snippet says it all (open is erode and dilate) *PIX* <http://tpgit.github.io/Leptonica/struct_pix.html> * *00405*<http://tpgit.github.io/Leptonica/morph_8c.html#a3b06b38bfe1f244a3aa9cf9568ab037d> *pixOpen*<http://tpgit.github.io/Leptonica/leptprotos_8h.html#af4c30de96cb73b128fb0253b79e397ae> (*PIX* <http://tpgit.github.io/Leptonica/struct_pix.html> *pixd, 00406 *PIX* <http://tpgit.github.io/Leptonica/struct_pix.html> *pixs, 00407 SEL *sel) 00408 { 00409 *PIX* <http://tpgit.github.io/Leptonica/struct_pix.html> *pixt; 00410 00411 *PROCNAME*<http://tpgit.github.io/Leptonica/environ_8h.html#a1a16952819bcbc526c998e3ac86f2e78> ("pixOpen"); 00412 00413 if ((pixd = *processMorphArgs2*<http://tpgit.github.io/Leptonica/morph_8c.html#abc65437bd0a9599c317ae53f9c28909f>(pixd, pixs, sel)) == *NULL*<http://tpgit.github.io/Leptonica/environ_8h.html#a070d2ce7b6bb7e5c05602aa8c308d0c4> ) 00414 return (*PIX*<http://tpgit.github.io/Leptonica/struct_pix.html>*) *ERROR_PTR*<http://tpgit.github.io/Leptonica/environ_8h.html#a38a8310a83847948c9ce6620983be468> ("pixd not returned", procName, pixd); 00415 00416 if ((pixt = *pixErode*<http://tpgit.github.io/Leptonica/leptprotos_8h.html#a4ad2d04919aa0b65fab93f693c9323b1> (*NULL*<http://tpgit.github.io/Leptonica/environ_8h.html#a070d2ce7b6bb7e5c05602aa8c308d0c4>, pixs, sel)) == *NULL*<http://tpgit.github.io/Leptonica/environ_8h.html#a070d2ce7b6bb7e5c05602aa8c308d0c4> ) 00417 return (*PIX*<http://tpgit.github.io/Leptonica/struct_pix.html>*) *ERROR_PTR*<http://tpgit.github.io/Leptonica/environ_8h.html#a38a8310a83847948c9ce6620983be468> ("pixt not made", procName, pixd); 00418 *pixDilate*<http://tpgit.github.io/Leptonica/leptprotos_8h.html#adac7488ed26d7c269cd10d0ea9cc2c79>(pixd, pixt, sel); 00419 *pixDestroy*<http://tpgit.github.io/Leptonica/leptprotos_8h.html#a1b238e61b64e4e5c62f44849cddb9658> (&pixt); 00420 00421 return pixd; 00422 } Cheers, Jozef
On Thursday, May 30, 2013 4:57:05 PM UTC+2, Dmitry Katsubo wrote: > Many thanks for the information, Johannes! > > I have played with *textord_max_noise_size *and it turned out that noise > in my particular case is not removed even when I set * > textord_max_noise_size=45*. Above that value almost all other characters > have been considered as noise. > > However *textord_heavy_nr=1* worked well for me. It looks like this very > setting works on its own and does not depend on values for other settings > mentioned. > > On 30.05.2013 9:11, Johannes Richter wrote: > > The parameter i meant is "*textord_max_noise_size*" and it defines the > maximum size of noise in pixels. You could also try the one you have found > in the list "*textord_heavy_nr*". > > "Opening and Closing Operators" are morphological operators. I searched > Wikipedia fo a nice example, but the english version is only a stub. > In your case the opening-operation is the way to go. Many image processing > frameworks include morphological operations. If your software does not > provide a opening operator look for *erosion* and *dilation*.(opening is > just a erosion followed by dilation) > > I made a quick example in gimp. > the picture "before.png" shows my object (the circle) with some noise i > want to remove. I executed the erosion operation on this picture with a > proper filter mask. The result is in picture "after erosion.png". The > circle has changed in size (and shape). As last step i executed the > dilation operation in gimp. The resulting image "after dilation.png" shows > only the circle. > > Depending on your objects and noise you need to choose a proper filter > mask for this operations. This operation will change the shape of your > characters slightly. > > > -- > With best regards, > Dmitry > > -- -- 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 unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
