Question

我正在尝试实现ios AR应用。我想做的是：如果用户触摸屏幕，则会发生屏幕截图，但是我只想将图像保存在正方形内并显示在左上角。因此，我需要裁剪屏幕截图。好像我传递了错误的正方形尺寸和位置？我究竟做错了什么？我是否使用了错误的坐标单位和大小单位？或者我是否在缩放比例？！

在此课程中，我将根据当前设备获得正方形的大小和位置

class ViewController: UIViewController, ARSKViewDelegate, UIPickerViewDataSource, UIPickerViewDelegate, SceneDelegate {

    var squareRect: CGRect = CGRect(x: 0, y: 0, width: 0, height: 0)

    @IBOutlet var sceneView: ARSKView!

    //that's the square
    @IBOutlet weak var squareImage: UIImageView!

    //this is where the cropped image should be displayed
    @IBOutlet weak var imageView: UIImageView!

    ...

    func getRect() -> CGRect{
        return squareRect
    }

    ...

    @objc func rotated(){

        if UIDevice.current.orientation.isLandscape {
            squareImage.frame.size.height = sceneView.frame.size.height * 0.77
            squareImage.frame.size.width = squareImage.frame.size.height
        }
        else {
            squareImage.frame.size.width = sceneView.frame.size.width * 0.77
            squareImage.frame.size.height = squareImage.frame.size.width
        }

        squareImage.center = sceneView.center

        squareRect = CGRect(origin: squareImage.frame.origin, size: squareImage.frame.size)
    }

在本课程中，将处理触摸并显示裁剪的图像：

protocol SceneDelegate{
    func getRect() -> CGRect
}

class Scene: SKScene {

    var sceneDelegate: SceneDelegate?

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

        guard let sceneView = self. view as? ARSKView else{ return }

        guard let imageView = sceneView.subviews.first as? UIImageView else { return }

        if let image = UIImage(pixelBuffer: currentFrame.capturedImage) {
            let cgImage: CGImage = CGImage(image)
            let croppedCGImage = cgImage.cropping(to: self.sceneDelegate!.getRect())
            let croppedImage = UIImage(cgImage: croppedCGImage!, scale: self.scale, orientation: up) 
            DispatchQueue.main.async {
                imageView.image = croppedImage
                    }

所以this (click for image)是我的代码的作用：它会裁剪位于右上角的非常小的图片？

编辑：

您几乎看不到图像上的正方形，因此我上传了another image。箭头指向正方形的边缘。

很显然，我传递了错误的正方形尺寸和位置！但是为什么呢？

我将squareRect的大小和宽度替换为：

let heightInPixel = squareImage.frame.height * UIScreen.main.scale
let widthInPixel = squareImage.frame.width* UIScreen.main.scale

它现在实际上显示了更大的图像，但是仍然太小。以及如何转换x和y位置？

cgImage.cropping（发送至：CGRect）返回的图像较小且错位，然后达到预期

0 个答案: