Here is my iOS OCR code for number recognition through Tesseract engine:
Tesseract* tesseract = [[Tesseract alloc] initWithDataPath:@"tessdata" language:@"eng"];
//set the tesseract variables
[tesseract setVariableValue:@"0123456789" forKey:@"tessedit_char_whitelist"];
NSString * temp = @"7";
[tesseract setVariableValue:temp forKey:@"tessedit_pageseg_mode"];
[tesseract setImage:argImage];
[tesseract recognize];
m_convertedText = [[tesseract recognizedText] copy];
Using above, I get some images recognized right. However sometimes I get 5 instead of 8, 6 instead of 5 and so on. My input images are quite perfect - pure black and white after binarizing.
Are there any other Tesseract options that I am missing to specify? I see there are 600+ options and very sparse documentation.
Best I could find was this website which lists all options but not yet very clear for an OCR beginner.
If someone has achieved 100% accuracy with numbers OCR using tesseract it will be really helpful.