UIImage与Iplimage相互转换

原创文章，转载请注明出处：http://www.cnblogs.com/mfryf/archive/2012/02/27/2369952.html 

Opencv中所有的图像处理都是Iplimage类型的格式，iso的sdk显示一张图像的对象类型是UIImage。因此，我们如果想在ios环境中使用opencv，

就必须把UIImage转换成Iplimage，处理之后再把Iplimage转换成UIImage。非常幸运的是，IOS的sdk为我们提供了转换API。

从UIImage创建一个Iplimage结构，代码如下：

// NOTE you SHOULD cvReleaseImage() for the return value when end of the code.
- (IplImage *)CreateIplImageFromUIImage:(UIImage *)image {
// Getting CGImage from UIImage
CGImageRef imageRef = image.CGImage;

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
// Creating temporal IplImage for drawing
IplImage *iplimage = cvCreateImage(
cvSize(image.size.width,image.size.height), IPL_DEPTH_8U, 4
);
// Creating CGContext for temporal IplImage
CGContextRef contextRef = CGBitmapContextCreate(
iplimage->imageData, iplimage->width, iplimage->height,
iplimage->depth, iplimage->widthStep,
colorSpace, kCGImageAlphaPremultipliedLast|kCGBitmapByteOrderDefault
);
// Drawing CGImage to CGContext
CGContextDrawImage(
contextRef,
CGRectMake(0, 0, image.size.width, image.size.height),
imageRef
);
CGContextRelease(contextRef);
CGColorSpaceRelease(colorSpace);

// Creating result IplImage
IplImage *ret = cvCreateImage(cvGetSize(iplimage), IPL_DEPTH_8U, 3);
cvCvtColor(iplimage, ret, CV_RGBA2BGR);
cvReleaseImage(&iplimage);

return ret;
}

使用玩iplimage之后，别忘记释放内存。cvreleaseImage().

从iplimage创建一张UIImage

代码如下：

// NOTE You should convert color mode as RGB before passing to this function
- (UIImage *)UIImageFromIplImage:(IplImage *)image {
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
// Allocating the buffer for CGImage
NSData *data =
[NSData dataWithBytes:image->imageData length:image->imageSize];
CGDataProviderRef provider =
CGDataProviderCreateWithCFData((CFDataRef)data);
// Creating CGImage from chunk of IplImage
CGImageRef imageRef = CGImageCreate(
image->width, image->height,
image->depth, image->depth * image->nChannels, image->widthStep,
colorSpace, kCGImageAlphaNone|kCGBitmapByteOrderDefault,
provider, NULL, false, kCGRenderingIntentDefault
);
// Getting UIImage from CGImage
UIImage *ret = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);
return ret;
}

尽情的在ios中使用opencv吧~