[Bug-ocrad] Re: OCRAD project: library is needed

[Antonio Diaz Diaz]

Igor Filippov [Contr] wrote:
> I noticed a small glitch - for some characters which are touching the
> boundaries of the bitmap_data the recognition fails. If I add an extra
> line of whitespace on all four sides (left,right,top,bottom) those
> characters get recognized, but the rest of them which were recognized
> before are not. Is there supposed to be exactly one line of whitespace
> on the side, or is it a bug?

The library interface (OCRAD_set_image*) should ignore any amount of 
surrounding whitespace. If what you describe is really happening, it is 
a bug.


> Ok, I think I know where the problem is.
> If there are two characters in the image block passed to OCRAD,
> i.e. "AB" OCRAD recognizes both of them and
> OCRAD_result_first_character() returns the first one - "A". I guess it
> makes sense in some circumstances, but in my situation I need to have
> either 
> 1) Recognition fails and does not return anything if there is more than
> one character,
> 2) Recognition sets a flag to indicate that more than one character was
> recognized.
>
> Perhaps 2) is already implemented? If not, I need it, otherwise the code
> is not functioning as a replacement for "Blob" which I used for single
> character recognition.

"2)" can currently be emulated, albeit not very conveniently:

  ( OCRAD_result_blocks( ocrdes ) == 1 &&
    OCRAD_result_lines( ocrdes, 0 ) == 1 &&
    OCRAD_result_line( ocrdes, 0, 0 ) != 0 &&
    strlen( OCRAD_result_line( ocrdes, 0, 0 ) == 1 )


I think implementing the function OCRAD_result_characters, which would 
return the number of characters in the image, could solve your problem. 
The resulting osra code could be like this:

  if( ocrdes && OCRAD_get_errno( ocrdes ) == OCRAD_ok &&
      OCRAD_set_image( ocrdes, opix, 0 ) == 0 &&
      ( height >= 10 || OCRAD_scale( ocrdes, 2 ) == 0 ) &&
      OCRAD_recognize( ocrdes, 0 ) == 0 &&
      OCRAD_result_characters( ocrdes ) == 1 )
    c2 = OCRAD_result_first_character( ocrdes );



Best regards,
Antonio.