如何在ios11上使用视觉框架的对象跟踪API？

Question

// init bounding
CGRect rect = CGRectMake(0, 0, 0.3, 0.3);
VNSequenceRequestHandler* reqImages = [[VNSequenceRequestHandler alloc] init];
VNRectangleObservation* ObserveRect = [VNRectangleObservation observationWithBoundingBox:rect];
VNTrackRectangleRequest* reqRect = [[VNTrackRectangleRequest alloc] initWithRectangleObservation:ObserveRect];
NSArray<VNRequest *>* requests = [NSArray arrayWithObjects:reqRect, nil];
BOOL bsucc = [reqImages performRequests:requests onCGImage:img.CGImage error:&error];

// get tracking bounding
VNDetectRectanglesRequest* reqRectTrack = [VNDetectRectanglesRequest new];
NSArray<VNRequest *>* requestsTrack = [NSArray arrayWithObjects:reqRectTrack, nil];
[reqImages performRequests:requestsTrack onCGImage:img.CGImage error:&error];

VNRectangleObservation* Observe = [reqRectTrack.results firstObject];
CGRect boundingBox = Observe.boundingBox;

为什么boundingBox值不正确？

如何找到ios11的vision.framework演示？

Answer 1

Vision Framework跟踪一个对象，可以在此链接找到一个演示：

https://github.com/jeffreybergier/Blog-Getting-Started-with-Vision

Blogger详细介绍了如何让演示工作，并有一个显示工作版本的gif。

希望这就是你所追求的目标。

Answer 2

以下是使用Vision框架的简单示例：https://github.com/artemnovichkov/iOS-11-by-Examples。我猜你有不同坐标系的问题。注意矩形转换：

cameraLayer.metadataOutputRectConverted(fromLayerRect: originalRect)

和

cameraLayer.layerRectConverted(fromMetadataOutputRect: transformedRect)