ios - 将 CGPoints (CIRectangleFeature) 从 Image 转换为 ImageView

Question

我正在创建一个检测矩形并使用相机 捕捉图像的 iPhone 应用程序。我在检测到的最大矩形上创建了一个叠加层，捕获后我有 4 个 CGPoints 使用 CIRectangleFeature 和一个图像。

CIRectangleFeature 中的所有 4 个点都是横向的，而我的应用是纵向的。

当我在下一个 Controller 的 UIImageView 中显示图像时，它们的坐标会受到干扰。 ImageView 处于 AspectFit 模式。我搜索并找到了一些解决方案，一个是

extension CGPoint {
func scalePointByCeficient(ƒ_x: CGFloat, ƒ_y: CGFloat, viewWidth: CGSize, imageWidth: CGSize) -> CGPoint {
    let scale: CGFloat;
    scale = min(ƒ_x, ƒ_y)

    var p: CGPoint = CGPoint(x: self.x, y: self.y)

    p.x *= scale
    p.y *= scale

    p.x += (viewWidth.width - imageWidth.width * scale) / 2.0
    p.y += (viewWidth.height - imageWidth.height * scale) / 2.0

    return p

}

func reversePointCoordinates() -> CGPoint {
    return CGPoint(x: self.y, y: self.x)
}

func sumPointCoordinates(add: CGPoint) -> CGPoint {
    return CGPoint(x: self.x + add.x, y: self.y + add.y)
}

func substractPointCoordinates(sub: CGPoint) -> CGPoint {
    return CGPoint(x: self.x - sub.x, y: self.y - sub.y)
}}

class ObyRectangleFeature : NSObject {

public var topLeft: CGPoint
public var topRight: CGPoint
public var bottomLeft: CGPoint
public var bottomRight: CGPoint

var myRect: CIRectangleFeature?

public var viewWidth: CGSize
public var imageWidth: CGSize

var centerPoint_OLD : CGPoint{
    get {

        myRect?.topLeft = self.topLeft
        myRect?.topRight = self.topRight
        myRect?.bottomLeft = self.bottomLeft
        myRect?.bottomRight = self.bottomRight

        let superCenter: CGPoint = CGPoint(x: (myRect?.bounds().midX)!, y: (myRect?.bounds().midY)!)

        return superCenter
    }

}
var centerPoint : CGPoint{
    get {
        myRect?.topLeft = self.topLeft
        myRect?.topRight = self.topRight
        myRect?.bottomLeft = self.bottomLeft
        myRect?.bottomRight = self.bottomRight

        let superCenter: CGPoint = CGPoint(x: (myRect?.bounds().midX)!, y: (myRect?.bounds().midY)!)

        return superCenter
    }

}

convenience init(rectObj rectangleFeature: CIRectangleFeature) {
    self.init()

    myRect = rectangleFeature

    topLeft = rectangleFeature.topLeft
    topRight = rectangleFeature.topRight
    bottomLeft = rectangleFeature.bottomLeft
    bottomRight = rectangleFeature.bottomRight
}

override init() {

    self.topLeft = CGPoint.zero
    self.topRight = CGPoint.zero
    self.bottomLeft = CGPoint.zero
    self.bottomRight = CGPoint.zero

    self.viewWidth = CGSize.zero
    self.imageWidth = CGSize.zero

    super.init()


}


public func rotate90Degree() -> Void {

    let centerPoint =  self.centerPoint

    //        /rotate cos(90)=0, sin(90)=1
    topLeft = CGPoint(x: centerPoint.x + (topLeft.y - centerPoint.y), y: centerPoint.y + (topLeft.x - centerPoint.x))
    topRight = CGPoint(x: centerPoint.x + (topRight.y - centerPoint.y), y: centerPoint.y + (topRight.x - centerPoint.x))
    bottomLeft = CGPoint(x: centerPoint.x + (bottomLeft.y - centerPoint.y), y: centerPoint.y + (bottomLeft.x - centerPoint.x))
    bottomRight = CGPoint(x: centerPoint.x + (bottomRight.y - centerPoint.y), y: centerPoint.y + (bottomRight.x - centerPoint.x))

    print(self.centerPoint)
}

public func  scaleRectWithCoeficient(ƒ_x: CGFloat, ƒ_y: CGFloat) -> Void {
    topLeft =  topLeft.scalePointByCeficient(ƒ_x: ƒ_x, ƒ_y: ƒ_y, viewWidth: self.viewWidth, imageWidth: self.imageWidth)
    topRight = topRight.scalePointByCeficient(ƒ_x: ƒ_x, ƒ_y: ƒ_y, viewWidth: self.viewWidth, imageWidth: self.imageWidth)
    bottomLeft = bottomLeft.scalePointByCeficient(ƒ_x: ƒ_x, ƒ_y: ƒ_y, viewWidth: self.viewWidth, imageWidth: self.imageWidth)
    bottomRight = bottomRight.scalePointByCeficient(ƒ_x: ƒ_x, ƒ_y: ƒ_y, viewWidth: self.viewWidth, imageWidth: self.imageWidth)
}

public func correctOriginPoints() -> Void {

    let deltaCenter = self.centerPoint.reversePointCoordinates().substractPointCoordinates(sub: self.centerPoint)

    let TL = topLeft
    let TR = topRight
    let BL = bottomLeft
    let BR = bottomRight

    topLeft = BL.sumPointCoordinates(add: deltaCenter)
    topRight = TL.sumPointCoordinates(add: deltaCenter)
    bottomLeft = BR.sumPointCoordinates(add: deltaCenter)
    bottomRight = TR.sumPointCoordinates(add: deltaCenter)

    print(self.centerPoint)
}}

它的叫声就像

ObyRectangleFeature *scaledRect = [[ObyRectangleFeature alloc] initWithRectObj:(id)rect_rect];

    float f_x = _sourceImageView.frame.size.width / _sourceImageView.image.size.width;
    float f_y = _sourceImageView.frame.size.height / _sourceImageView.image.size.height;

    [scaledRect setViewWidth:_sourceImageView.bounds.size];
    [scaledRect setImageWidth:_sourceImageView.image.size];

    [scaledRect scaleRectWithCoeficientWithƒ_x:f_y ƒ_y:f_x];
    [scaledRect rotate90Degree];
    [scaledRect correctOriginPoints];

基本上它会检查比例因子并将点转换为 UIImageView 坐标，然后根据需要考虑景观因子将其旋转 90 度或更多。但是我得到的结果有点问题

如您所见，制作的矩形移到了卡片下方。关于如何解决这个问题的任何想法？

Answer 1

问题是 UIImageView 的 contentMode 改变了图像在 View 中的放置位置。看来您正在使用宽高比，因此您必须计算 UImageView 中有多少是黑条，然后将图像大小除以 imageView 大小，然后根据黑条添加偏移量。这真的不难，但数学可能很棘手。我建议使用 https://github.com/nubbel/UIImageView-GeometryConversion它对所有不同的内容模式进行数学计算。