I am trying to use http://ift.tt/1hNCkae library to read text from shopping receipt.

MyViewController.h


#import <TesseractOCR/TesseractOCR.h>

@interface MyViewController : UIViewController <G8TesseractDelegate>
@end

MyViewController.m


@implementation MyViewController
- (void)viewDidLoad
{
    [super viewDidLoad];

    // Languages are used for recognition (e.g. eng, ita, etc.). Tesseract engine
    // will search for the .traineddata language file in the tessdata directory.
    // For example, specifying "eng+ita" will search for "eng.traineddata" and
    // "ita.traineddata". Cube engine will search for "eng.cube.*" files.
    // See http://ift.tt/1go8FEN.

    // Create your G8Tesseract object using the initWithLanguage method:
    G8Tesseract *tesseract = [[G8Tesseract alloc] initWithLanguage:@"eng"];

    // Optionaly: You could specify engine to recognize with.
    // G8OCREngineModeTesseractOnly by default. It provides more features and faster
    // than Cube engine. See G8Constants.h for more information.
    //tesseract.engineMode = G8OCREngineModeTesseractOnly;

    // Set up the delegate to receive Tesseract's callbacks.
    // self should respond to TesseractDelegate and implement a
    // "- (BOOL)shouldCancelImageRecognitionForTesseract:(G8Tesseract *)tesseract"
    // method to receive a callback to decide whether or not to interrupt
    // Tesseract before it finishes a recognition.
    tesseract.delegate = self;

    // Optional: Limit the character set Tesseract should try to recognize from
    tesseract.charWhitelist = @"0123456789";

    // This is wrapper for common Tesseract variable kG8ParamTesseditCharWhitelist:
    // [tesseract setVariableValue:@"0123456789" forKey:kG8ParamTesseditCharBlacklist];
    // See G8TesseractParameters.h for a complete list of Tesseract variables

    // Optional: Limit the character set Tesseract should not try to recognize from
    //tesseract.charBlacklist = @"OoZzBbSs";

    // Specify the image Tesseract should recognize on
    tesseract.image = [[UIImage imageNamed:@"walmart_receipt.png"] g8_blackAndWhite];

    // Optional: Limit the area of the image Tesseract should recognize on to a rectangle
    tesseract.rect = CGRectMake(20, 20, 100, 100);

    // Optional: Limit recognition time with a few seconds
    tesseract.maximumRecognitionTime = 2.0;

    // Start the recognition
    [tesseract recognize];

    // Retrieve the recognized text
    NSLog(@"Text:%@", [tesseract recognizedText]);

    // You could retrieve more information about recognized text with that methods:
    NSArray *characterBoxes = [tesseract recognizedBlocksByIteratorLevel:G8PageIteratorLevelSymbol];
    NSLog(@"characterBoxes:%@", characterBoxes);

    NSArray *paragraphs = [tesseract recognizedBlocksByIteratorLevel:G8PageIteratorLevelParagraph];
    NSLog(@"paragraphs:%@", paragraphs);

    NSArray *characterChoices = tesseract.characterChoices;
    NSLog(@"characterChoices:%@", characterChoices);

    UIImage *imageWithBlocks = [tesseract imageWithBlocks:characterBoxes drawText:YES thresholded:NO];
}

@end

When I run my project, I see output as


2015-03-01 12:38:04.888 testImage[45600:70b] Text: 13
53 142  11

2015-03-01 12:38:04.889 testImage[45600:70b] characterBoxes:(
    "(2.56%) ' '",
    "(74.74%) '1'",
    "(69.03%) '3'",
    "(89.08%) '5'",
    "(72.80%) '3'",
    "(22.93%) ' '",
    "(78.33%) '1'",
    "(67.23%) '4'",
    "(70.94%) '2'",
    "(15.52%) ' '",
    "(80.01%) '1'",
    "(68.51%) '1'"
)
2015-03-01 12:38:04.890 testImage[45600:70b] paragraphs:(
    "(13.67%) ' 13\n53 142  11\n\n'"
)
2015-03-01 12:38:04.890 testImage[45600:70b] characterChoices:(
        (
        "(2.56%) ' '"
    ),
        (
        "(74.74%) '1'"
    ),
        (
        "(69.03%) '3'"
    ),
        (
        "(89.08%) '5'"
    ),
        (
        "(72.80%) '3'"
    ),
        (
        "(22.93%) ' '"
    ),
        (
        "(78.33%) '1'"
    ),
        (
        "(67.23%) '4'"
    ),
        (
        "(70.94%) '2'"
    ),
        (
        "(5.45%) ' '"
    ),
        (
        "(80.01%) '1'"
    ),
        (
        "(68.51%) '1'"
    )
)