如何自定義相機視圖並捕獲疊加中的零件？

Question

我需要構建類似於以下內容的自定義相機視圖： 示例圖像

我使用了AVFoundation並將UIImageView放在AVCaptureVideoPreviewLayer上，它看起來幾乎是相同的（盡管我不確定這是否正確，這就是我這樣寫標題的方式）。 我正在捕獲圖像並將其保存到圖庫，但是我只需要中間矩形區域中的圖像即可。

有什么建議怎么做嗎？

提前致謝！

Answer 1

您需要在疊加圖像視圖的上下文中裁剪圖像。在下面的功能中傳遞捕獲的圖像可能會有所幫助。

func cropToBounds(image: UIImage) -> UIImage
{
        let contextImage: UIImage = UIImage(cgImage: image.cgImage!)
        let contextSize: CGSize = contextImage.size
        let widthRatio = contextSize.height/UIScreen.main.bounds.size.width
        let heightRatio = contextSize.width/UIScreen.main.bounds.size.height

        let width = (self.imgOverlay?.frame.size.width)!*widthRatio
        let height = (self.imgOverlay?.frame.size.height)!*heightRatio
        let x = ((self.imgOverlay?.frame.origin.x)!)*widthRatio
        let y = (self.imgOverlay?.frame.origin.y)!*heightRatio
        let rect = CGRect(x: x, y: y, width: height, height: width)

        let imageRef: CGImage = contextImage.cgImage!.cropping(to: rect)!
        let image: UIImage = UIImage(cgImage: imageRef, scale: image.scale, orientation: image.imageOrientation)
        return image
}

Answer 2

實際上，Nishant Bhindi的答案需要一些更正。 下面的代碼將完成工作：

func cropToBounds(image: UIImage) -> UIImage
{
    let contextImage: UIImage = UIImage(cgImage: image.cgImage!)
    let contextSize: CGSize = contextImage.size
    let widthRatio = contextSize.height/UIScreen.main.bounds.size.height
    let heightRatio = contextSize.width/UIScreen.main.bounds.size.width

    let width = (self.imgOverlay?.frame.size.width)!*widthRatio
    let height = (self.imgOverlay?.frame.size.height)!*heightRatio
    let x = (contextSize.width/2) - width/2
    let y = (contextSize.height/2) - height/2
    let rect = CGRect(x: x, y: y, width: width, height: height)

    let imageRef: CGImage = contextImage.cgImage!.cropping(to: rect)!
    let image: UIImage = UIImage(cgImage: imageRef, scale: 0, orientation: image.imageOrientation)
    return image
}