opencv UIimage，cvmat 和IplImage的相互转换

1.opencv UIimage转换cvmat

+ (cv::Mat)cvMatFromUIIMage:(UIImage *)image
{
    @synchronized (image) {
        CGColorSpaceRef colorSpace = CGImageGetColorSpace(image.CGImage);
        CGFloat cols = image.size.width;
        CGFloat rows = image.size.height;

        cv::Mat cvMat(rows, cols, CV_8UC4);

        CGContextRef contextRef = CGBitmapContextCreate(cvMat.data,
                                                        cols,
                                                        rows,
                                                        8,
                                                        cvMat.step[0],
                                                        colorSpace,
                                                        kCGImageAlphaNoneSkipLast | kCGBitmapByteOrderDefault);

        CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), image.CGImage);
        CGContextRelease(contextRef);
        return cvMat;
    }
}

2.opencv cvmat转换UIimage

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

    if (cvMat.elemSize() == 1) {//能够根据这个决定使用哪一种
        colorSpace = CGColorSpaceCreateDeviceGray();
    } else {
        colorSpace = CGColorSpaceCreateDeviceRGB();
    }

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

    // Creating CGImage from cv::Mat
    CGImageRef imageRef = CGImageCreate(cvMat.cols,                                 //width
                                        cvMat.rows,                                 //height
                                        8,                                          //bits per component
                                        8 * cvMat.elemSize(),                       //
                                        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;
}

3.opencv UIimage转换IplImage

+ (IplImage *)IplImageFromUIImage:(UIImage *)image
{
    CGImageRef imageRef = image.CGImage;

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    IplImage *iplimage = cvCreateImage(cvSize(image.size.width, image.size.height), IPL_DEPTH_8U, 4);
    CGContextRef contextRef = CGBitmapContextCreate(iplimage->imageData, iplimage->width, iplimage->height,
                                                    iplimage->depth, iplimage->widthStep,
                                                    colorSpace, kCGImageAlphaPremultipliedLast|kCGBitmapByteOrderDefault);
    CGContextDrawImage(contextRef, CGRectMake(0, 0, image.size.width, image.size.height), imageRef);
    CGContextRelease(contextRef);
    CGColorSpaceRelease(colorSpace);
    return iplimage;
}

4.opencv IplImage转换UIimage

+ (UIImage *)UIImageFromIplImage:(IplImage *)image
{
    NSLog(@"IplImage (%d, %d) %d bits by %d channels, %d bytes/row %s", image->width, image->height, image->depth, image->nChannels, image->widthStep, image->channelSeq);
    UIImage *result = nil;

    NSData *data = [NSData dataWithBytes:image->imageData length:image->imageSize];
    CGDataProviderRef provider = CGDataProviderCreateWithCFData((CFDataRef)data);
    if (provider) {
        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
        if (colorSpace) {
            CGImageRef imageRef = CGImageCreate(image->width, image->height,
                                                image->depth, image->depth * image->nChannels, image->widthStep,
                                                colorSpace, kCGImageAlphaNone|kCGBitmapByteOrderDefault,
                                                provider, NULL, NO, kCGRenderingIntentDefault);

            if (imageRef) {
                result = [UIImage imageWithCGImage:imageRef];
                CGImageRelease(imageRef);
            }

            CGColorSpaceRelease(colorSpace);
        }

        CGDataProviderRelease(provider);
    }

    return result;
}