//转换图片- (UIImage *) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer {    // 为媒体数据设置一个CMSampleBuffer的Core Video图像缓存对象    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);    // 锁定pixel buffer的基地址    CVPixelBufferLockBaseAddress(imageBuffer, 0);        // 得到pixel buffer的基地址    void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);        // 得到pixel buffer的行字节数    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);    // 得到pixel buffer的宽和高    size_t width = CVPixelBufferGetWidth(imageBuffer);    size_t height = CVPixelBufferGetHeight(imageBuffer);        // 创建一个依赖于设备的RGB颜色空间    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();        // 用抽样缓存的数据创建一个位图格式的图形上下文（graphics context）对象    CGContextRef context = CGBitmapContextCreate(baseAddress, width, height, 8,                                                 bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);    // 根据这个位图context中的像素数据创建一个Quartz image对象    CGImageRef quartzImage = CGBitmapContextCreateImage(context);    // 解锁pixel buffer    CVPixelBufferUnlockBaseAddress(imageBuffer,0);        // 释放context和颜色空间    CGContextRelease(context);    CGColorSpaceRelease(colorSpace);        // 用Quartz image创建一个UIImage对象image    UIImage *image = [UIImage imageWithCGImage:quartzImage];        // 释放Quartz image对象    CGImageRelease(quartzImage);        return (image);}

保存图片

//保存图片- (void)saveImageToPhotos:(UIImage*)savedImage{    UIImageWriteToSavedPhotosAlbum(savedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);}// 指定回调方法- (void)image: (UIImage *) image didFinishSavingWithError: (NSError *) error contextInfo: (void *) contextInfo{    NSString *msg = nil ;    if(error != NULL){        msg = @"保存图片失败" ;    }else{        msg = @"保存图片成功" ;    }    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"保存图片结果提示"                                                    message:msg                                                   delegate:self                                          cancelButtonTitle:@"确定"                                          otherButtonTitles:nil];    [alert show];}

//调用示例               

UIImage *img=[self imageFromSampleBuffer:detectSampleBufferRef];

[self saveImageToPhotos:img];