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OCR Character Confidence

Posted: Fri Aug 07, 2009 7:55 am
by ganeshj
I am doing OCR on an image and checking for Character Confidence.

for the Word FULL NAME when i use OCRTesseractGetCharConfidence

i get
F=19
U=19
L=19
L=19

N=65
A=65
M=65
E=65

When i debug in .Net i see the following values in the GDImaging Object
F=49
U=49
L=49
L=49

N=166
A=166
M=166
E=166

Can you tell me how these 2 values are related also which is more accurate the lower or higher value.
Also i have noticed that Confidence levels of a single word are always same as you can see above this is the case with other words as well. Is the confidence at Character or Word level.

Regards
Ganesh

Re: OCR Character Confidence

Posted: Tue Aug 25, 2009 12:51 pm
by ganeshj
Hi Loic,

Any update on the above question. Thanks.

Re: OCR Character Confidence

Posted: Mon Sep 07, 2009 1:00 pm
by ganeshj
Still waiting for a reply on this.

Re: OCR Character Confidence

Posted: Mon Sep 07, 2009 2:32 pm
by Loïc
Hi,
Can you tell me how these 2 values are related also which is more accurate the lower or higher value.
You probably done something different to make test such as image filter or using different dictionary.
If you are able to reproduce this behavior in a comprehensive small application you can send it to esupport (at) gdpicture (dot) com for more investigations.


Is the confidence at Character or Word level.
word.

Kind regards,

Loïc

Re: OCR Character Confidence

Posted: Thu Dec 22, 2016 6:21 pm
by ategen
I'm just guessing, but I believe what you are seeing is a difference in the range.

19 is 19% (range 0-100), but 49 is in the range of (0-255). 19 / 100 * 256 = 48.86.
65 / 100 * 256 = 166.4

Re: OCR Character Confidence

Posted: Tue Jan 29, 2019 2:40 pm
by Gabriela
Hello,

You can try this using the GdPictureOCR class now:
https://www.gdpicture.com/guides/gdpicture/we ... reOCR.html