cv :: mat到UIImage转换不能恢复精确图像

Question

我正在使用此函数将cv :: mat转换为UIImage。

-(UIImage *)UIImageFromCVMat:(cv::Mat)cvMat 
{ 
    NSData *data = [NSData dataWithBytes:cvMat.data length:cvMat.elemSize()*cvMat.total()]; 
    CGColorSpaceRef colorSpace; 

    if (cvMat.elemSize() == 1) { 
     colorSpace = CGColorSpaceCreateDeviceGray(); 
    } else { 
     colorSpace = CGColorSpaceCreateDeviceRGB(); 
    } 

    CGDataProviderRef provider = CGDataProviderCreateWithCFData((CFDataRef)data); 

    // Creating CGImage from cv::Mat 
    CGImageRef imageRef = CGImageCreate(cvMat.cols,         //width 
             cvMat.rows,         //height 
             8,           //bits per component 
             8 * cvMat.elemSize(),      //bits per pixel 
             cvMat.step[0],       //bytesPerRow 
             colorSpace,         //colorspace 
             kCGImageAlphaNone|kCGBitmapByteOrderDefault,// bitmap info 
             provider,         //CGDataProviderRef 
             NULL,          //decode 
             false,          //should interpolate 
             kCGRenderingIntentDefault     //intent 
             ); 


    // Getting UIImage from CGImage 
    UIImage *finalImage = [UIImage imageWithCGImage:imageRef]; 
    CGImageRelease(imageRef); 
    CGDataProviderRelease(provider); 
    CGColorSpaceRelease(colorSpace); 

    return finalImage; 
} 

恢复图像颜色与原始图像不匹配。我从CvVideoCamera代理获得cv：Mat

- (void)processImage:(Mat&)image 
{ 
    UIImage* img = [self UIImageFromCVMat:image] 
} 

这段代码有什么问题。

Answer 1

它可能与openCV（bgr）的默认颜色空间顺序有关。我认为你应该检查CGImageCreate构造函数来找出根本原因。

Answer 2

这里是我工作的代码

- (UIImage *)UIImageFromMat:(cv::Mat)image 
{ 
    cvtColor(image, image, CV_BGR2RGB); 
    NSData *data = [NSData dataWithBytes:image.data length:image.elemSize()*image.total()]; 

    CGColorSpaceRef colorSpace; 

    if (image.elemSize() == 1) { 
     colorSpace = CGColorSpaceCreateDeviceGray(); 
    } else { 
     colorSpace = CGColorSpaceCreateDeviceRGB(); 
    } 

    CGDataProviderRef provider = CGDataProviderCreateWithCFData((CFDataRef)data);//CGDataProviderCreateWithCFData((__bridge CFDataRef)data); 

    // Creating CGImage from cv::Mat 
    CGImageRef imageRef = CGImageCreate(image.cols,         //width 
             image.rows,         //height 
             8,           //bits per component 
             8 * image.elemSize(),      //bits per pixel 
             image.step.p[0],       //bytesPerRow 
             colorSpace,         //colorspace 
             kCGImageAlphaNone|kCGBitmapByteOrderDefault,// bitmap info 
             provider,         //CGDataProviderRef 
             NULL,          //decode 
             false,          //should interpolate 
             kCGRenderingIntentDefault     //intent 
             ); 


    // Getting UIImage from CGImage 
    UIImage *finalImage = [UIImage imageWithCGImage:imageRef]; 
    //[self.imgView setImage:finalImage]; 
    CGImageRelease(imageRef); 
    CGDataProviderRelease(provider); 
    CGColorSpaceRelease(colorSpace); 

    return finalImage; 

}