IOS OCR tesseract does not free memory after zero and uses ACR

I have spent over 24 hours on a debugging and troubleshooting issue in tesseract, the problem is that I execute the following function on multiple images and every time I keep track of the memory and I found that the memory grows every time I call below strings

Tesseract* tesseract = [[Tesseract alloc] initWithLanguage:@"eng+ita"];

      

        
        
        
      

    

and it is not affected by the bottom line

tesseract = nil;

      

        
        
        
      

    

below is a complete function called

    -(void)recognizeImageWithTesseract:(UIImage *)img
    {

     UIImage *testb = [img blackAndWhite];

       Tesseract* tesseract = [[Tesseract alloc] initWithLanguage:@"eng+ita"];

       tesseract.delegate = self;
         [tesseract setVariableValue:@"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+-/*._=':!)(" forKey:@"tessedit_char_whitelist"]; //limit search
        [tesseract setImage:testb];
        [tesseract recognize];
         recognizedText = [tesseract recognizedText];
        tesseract = nil; //deallocate and free all memory
}

      

        
        
        
      

    

UPDATE 1:

after deep troubleshooting, i found the tesseract setimage code is the cause, the code is as below, i need to know which code i should update to fix this issue.

- (void)setImage:(UIImage *)image {

    if (image == nil || image.size.width <= 0 || image.size.height <= 0) {
        NSLog(@"WARNING: Image has not size!");
        return;
    }

    self.imageSize = image.size; //self.imageSize used in the characterBoxes method
    int width = self.imageSize.width;
    int height = self.imageSize.height;

    CGImage *cgImage = image.CGImage;
    CFDataRef data = CGDataProviderCopyData(CGImageGetDataProvider(cgImage));
    _pixels = CFDataGetBytePtr(data);

    size_t bitsPerComponent = CGImageGetBitsPerComponent(cgImage);
    size_t bitsPerPixel = CGImageGetBitsPerPixel(cgImage);
    size_t bytesPerRow = CGImageGetBytesPerRow(cgImage);

    tesseract::ImageThresholder *imageThresholder = new tesseract::ImageThresholder();

    assert(bytesPerRow < MAX_INT32);
    {
        imageThresholder->SetImage(_pixels,width,height,(int)(bitsPerPixel/bitsPerComponent),(int)bytesPerRow);
        _tesseract->SetImage(imageThresholder->GetPixRect());
    }

    imageThresholder->Clear();
    CFRelease(data);
    delete imageThresholder;
    imageThresholder = nil;
}

      

        
        
        
      

    

please support me to resolve this issue.

thanks alot