图像处理openCV

Question

  

可能重复：
  OCR using openCV

我想将灰色图像转换为黑白图像（具有良好的对比度）。我正在使用openCV。我在过去3天里一直在努力，但我的输出图像并不清楚如下所示。

由于

原始图片：

输出图片：

Answer 1

试试这个会帮助你获得正确的图像

UIImage *image=[UIImage imageNamed:@"EUqAd.jpg"];
        UIImageView *imageView=[[UIImageView alloc]initWithFrame:CGRectMake(20, 20, 280, 150)];
        imageView.image=image;
        [self.view addSubview:imageView];

    CGRect rect = CGRectMake(0, 0, image.size.width, image.size.height);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextClipToMask(context, rect, image.CGImage);
    CGContextSetFillColorWithColor(context, [[UIColor whiteColor] CGColor]);
    CGContextFillRect(context, rect);
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    UIImage *flippedImage = [UIImage imageWithCGImage:img.CGImage
                                                scale:1.0 orientation: UIImageOrientationDownMirrored];

    UIImageView *imageView1=[[UIImageView alloc]initWithFrame:CGRectMake(20, 200, 280, 150)];
    imageView1.image=flippedImage;
    [self.view addSubview:imageView1];