最近公司碰到一个需求：聊天禁止二维码。然后碰到微信的个人名片二维码有一张识别不出来（个人二维码有很多样式的）
识别二维码
我是写的一个UIImage的类目实现
- (NSString *)qrimageToStr{ CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:nil]; UIImage *image = [self imageCompressForWidth:640]; NSArray *features = [detector featuresInImage:[CIImage imageWithCGImage:image.CGImage]];
__block NSString *message = nil;
[features enumerateObjectsUsingBlock:^(CIFeature * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
if ([obj isKindOfClass:[CIQRCodeFeature class]]) {
message = [(CIQRCodeFeature *)obj messageString];
*stop=YES;
}
}];
return message;
}
最开始发现不能识别二维码就以为是识别精度问题，然后就设置了options:@{CIDetectorAccuracy:CIDetectorAccuracyHigh}
发现还是识别不出来，于是想到下压缩下图片试试，没想到一试就ok了。
压缩图片
- (UIImage *)imageCompressForWidth:(CGFloat)defineWidth
{
CGSize imageSize = self.size;
CGFloat width = imageSize.width;
CGFloat height = imageSize.height;
CGFloat targetWidth = defineWidth;
NSInteger targetHeight = (targetWidth / width) * height;
UIGraphicsBeginImageContext(CGSizeMake(targetWidth, targetHeight));
[self drawInRect:CGRectMake(0,0,targetWidth, targetHeight)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
识别二维码时，压缩图片会提高精度和效率。
当二维码识别不出来时可以试试压缩图片
