Predict Digit takes a 28x28 image and predicts the digit

predictDigit.m

-(void)predictDigit{
  
    //unscaled image
    //self.imageToDetect = [[CIImage alloc]initWithImage:self.drawingCanvas.image];
    
    //scaled image to 28x28
    UIImage *scaledCanvasImage = [self imageWithImage:self.drawingCanvas.image scaledToSize:CGSizeMake(28, 28)];
    self.imageToDetect = [[CIImage alloc]initWithImage:scaledCanvasImage];
    
    MLModel *ml_model = [[[keras_mnist_cnn alloc] init] model];
    VNCoreMLModel *vnc_core_ml_model = [VNCoreMLModel modelForMLModel: ml_model error:nil];
    
    VNCoreMLRequest *request = [[VNCoreMLRequest alloc] initWithModel: vnc_core_ml_model completionHandler: (VNRequestCompletionHandler) ^(VNRequest *request, NSError *error){
        NSArray *results = [request.results copy];
        
        VNCoreMLFeatureValueObservation *res = ((VNCoreMLFeatureValueObservation *)(results[0]));
        
        NSNumber *prediction = [NSNumber numberWithFloat:0];
        NSNumber *compare= [NSNumber numberWithFloat:0];
        int atIndex = 0;
        
        
        for(int i = 0; i<[res.featureValue multiArrayValue].count; i++){
            
            compare = [[res.featureValue multiArrayValue] objectAtIndexedSubscript:i];
            if([compare floatValue] > [prediction floatValue]){
                prediction = compare;
                atIndex = i;
            }
        }
        
       // double predictionPercentage = [[[res.featureValue multiArrayValue] objectAtIndexedSubscript:atIndex] doubleValue];
        
        NSString *result = @"";
        self.resultLabel.text = [result stringByAppendingFormat: @"Digit may be: %i", atIndex];
    }];
    
    NSDictionary *options_dict = [[NSDictionary alloc] init];
    NSArray *request_array = @[request];
    
    VNImageRequestHandler *handler = [[VNImageRequestHandler alloc] initWithCIImage:self.imageToDetect options:options_dict];
    dispatch_queue_t myCustomQueue;
    myCustomQueue = dispatch_queue_create("com.lukau.VNImageRequestHandlerQueue", NULL);
    
    self.resultLabel.text = @"Predicting...";
    dispatch_sync(myCustomQueue, ^{
        [handler performRequests:request_array error:nil];
        
    });
}