iphone - 如何在 ARToolKitPlus 中使用 UIImage？ (UIImage 到 CVImageBufferRef 的转换)

Question

我有两种算法可以检测 AR 标记(ARToolKit 和 Infi)。我让他们在 iPhone 上实时检测标记。在这个阶段，我想比较一下它们的速度和准确性。我想准备一系列图像并对其进行测试识别。我可以用 infi 做到这一点，但我无法设法将 ARToolKit 与 UIImage 一起使用。

ARToolKit 使用 CVImageBuffer 来识别标记:

- (Marker *)detectMarkerInImageBuffer:(CVImageBufferRef)imageBuffer {

    /*We lock the buffer and get the address of the first pixel*/
    CVPixelBufferLockBaseAddress(imageBuffer,0);
    unsigned char *baseAddress = (unsigned char *) CVPixelBufferGetBaseAddress(imageBuffer);
    tracker->calc(baseAddress);

如何使用/转换 UIImage 来实现 baseAddress，以便将其发送到 tracker->calc？

使用 infi，我首先从缓冲区创建 IplImage 或将 UIImage 转换为 IplImage，然后在这两种情况下:

Buffer* buffer = new Buffer();

buffer->setBuffer( (unsigned char *) iplImg->imageData, iplImg->width, iplImg->height);

Answer 1

我在这里找到了答案:How do I export UIImage array as a movie?

这就是我要找的

- (CVPixelBufferRef) pixelBufferFromCGImage: (CGImageRef) image
{
    NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
        [NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
        [NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
        nil];
    CVPixelBufferRef pxbuffer = NULL;
    CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, frameSize.width,
        frameSize.height, kCVPixelFormatType_32ARGB, (CFDictionaryRef) options, 
        &pxbuffer);
    NSParameterAssert(status == kCVReturnSuccess && pxbuffer != NULL);

    CVPixelBufferLockBaseAddress(pxbuffer, 0);
    void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
    NSParameterAssert(pxdata != NULL);

    CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(pxdata, frameSize.width,
        frameSize.height, 8, 4*frameSize.width, rgbColorSpace, 
        kCGImageAlphaNoneSkipFirst);
    NSParameterAssert(context);
    CGContextConcatCTM(context, frameTransform);
    CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image), 
        CGImageGetHeight(image)), image);
    CGColorSpaceRelease(rgbColorSpace);
    CGContextRelease(context);

    CVPixelBufferUnlockBaseAddress(pxbuffer, 0);

    return pxbuffer;
}