使用平移、旋转和捏合手势编辑后如何保存 UIImage

Question

我正在尝试使用 UIPanGesture、UIRotateGesture 和 UIPinchGesture 来实现编辑图像。编辑后，我想保存编辑后的UIImage。

我完成了编辑图像功能。

但我不知道如何保存完全像原生iOS Camera App.

平移手势工作正常。

我的问题是旋转和缩放。

如何设置UIImage的中心锚点？

当我从转换信息中保存 UIImage 时，UIImage 的结果看起来不同，因为旋转和缩放，然后它总是基于 (0,0)

 @IBAction func showEditedImage(_ sender: Any) {


        let image = preview.image!
        var drawingRect : CGRect = CGRect.zero
        drawingRect.size = preview.frame.size

        let scale = transformedImg.frame.width / (preview.image?.size.width)!
        let height = (preview.image?.size.height)! * scale

        UIGraphicsBeginImageContextWithOptions(CGSize(width: transformedImg.frame.width, height: height), false, 0)

        let context = UIGraphicsGetCurrentContext()
        context!.concatenate(preview.transform)

        image.draw(in: CGRect(x: 0, y: 0, width: transformedImg.frame.width, height: height))
        resultsImg = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext();

        transformedImg.image = resultsImg
    }

这是我的全部代码。

import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var preview: UIImageView!
    @IBOutlet weak var frame: UIView!
    @IBOutlet weak var transformedImg: UIImageView!

    //save edited image
    var resultsImg : UIImage!

    override func viewDidLoad() {

        resultsImg = UIImage()
        super.viewDidLoad()
    }


       @IBAction func showEditedImage(_ sender: Any) {


    let image = preview.image!
    var drawingRect : CGRect = CGRect.zero
    drawingRect.size = preview.frame.size

    let scale = transformedImg.frame.width / (preview.image?.size.width)!
    let height = (preview.image?.size.height)! * scale

    UIGraphicsBeginImageContextWithOptions(CGSize(width: transformedImg.frame.width, height: height), false, 0)

    let context = UIGraphicsGetCurrentContext()
    context!.concatenate(preview.transform)

    image.draw(in: CGRect(x: 0, y: 0, width: transformedImg.frame.width, height: height))
    resultsImg = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext();

    transformedImg.image = resultsImg
}

    @IBAction func pinchaction(_ sender: UIPinchGestureRecognizer) {

        preview.transform = preview.transform.scaledBy(x: sender.scale, y: sender.scale)

        sender.scale = 1
    }

    @IBAction func rotateaction(_ sender: UIRotationGestureRecognizer) {

        let rotate = sender.rotation
        preview.transform = preview.transform.rotated(by: rotate)


        sender.rotation = 0

    }

    @IBAction func panaction(_ sender: UIPanGestureRecognizer) {

        let points = sender.translation(in: self.frame)
        preview.transform = preview.transform.translatedBy(x: points.x, y: points.y)

        let translatedCenter = CGPoint(x:self.frame.center.x + points.x, y:self.frame.center.y + points.y)

        sender.setTranslation(CGPoint.zero, in: self.frame)

    }



}

环境：XCode9 + Swift 4

2017 年 10 月 14 日更新

我解决了我的问题

 @IBAction func showEditedImage(_ sender: Any) {

        let image = preview.image!
        var drawingRect : CGRect = CGRect.zero
        drawingRect.size = preview.frame.size

        let scale = transformedImg.frame.width / (preview.image?.size.width)!
        let height = (preview.image?.size.height)! * scale


        UIGraphicsBeginImageContextWithOptions(CGSize(width: transformedImg.frame.width, height: height), false, 0)

        let context = UIGraphicsGetCurrentContext()

        //Set Center Position before Scale, Rotate Image
        context?.translateBy(x: transformedImg.frame.width / 2, y: height / 2)

        //Applied Translate, Scale, Rotate
        context!.concatenate(preview.transform)

        context?.translateBy(x: -(transformedImg.frame.width / 2), y: -(height / 2))

        image.draw(in: CGRect(x: 0, y: 0, width: transformedImg.frame.width, height: height))
        resultsImg = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext();

        transformedImg.image = resultsImg
    }

Answer 1

我在 Swift 2.3 中实现了这个功能，所以你可以在 Swift 4.Swift 中转换后使用它。

fun SaveImage()
{
    if myImageView != nil
    {
       // You should hide here your Buttons,Labels, etc.

    let layer = UIApplication.sharedApplication().keyWindow!.layer
    let scale = UIScreen.mainScreen().scale
    UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale);

    layer.renderInContext(UIGraphicsGetCurrentContext()!)
    let screenshot = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

       // Now here you can UnHide(Show) your Buttons,Labels,etc
    UIImageWriteToSavedPhotosAlbum(screenshot, nil, nil, nil)
    let alert = UIAlertView(title: "Alert !!",
        message: "Your image has been saved to Photo Library",
        delegate: nil,
        cancelButtonTitle: "OK")
    alert.show()

    }
    else
    {
        let alert = UIAlertView(title: "Alert !!",
            message: "Please first Select/Capture Image",
            delegate: nil,
            cancelButtonTitle: "OK")
        alert.show()
    }

}

Answer 2

我有一个名为 myView 的具有透明背景的 UIIView，我将 UIImageView 作为子视图添加到 myView 中，然后我在 myView 上应用 UIRotationGestureRecognizer，以便在此处旋转我的图像是我的 UIRotationGestureRecognizer 的 @IBAction 函数....

@IBAction func rotateGesture(sender: UIRotationGestureRecognizer) {
    if let view = sender.view {
        view.transform = CGAffineTransformRotate(view.transform, sender.rotation)
        sender.rotation = 0
    }
}

Answer 3

我遇到了类似的问题，不同之处在于我不想以与原始图像相同的比例保存编辑后的图像。

在尝试调整上述解决方案后，我想到拍摄包含 rotated/zoomed UIImageView 的 UIView 的快照会更容易。

我使用了这里提出的解决方案的一个版本：

在 Swift 4:

private func getEditedImage(container: UIView) -> UIImage? {
    UIGraphicsBeginImageContextWithOptions(container.bounds.size, false, 0.0)
    drawHierarchy(in: container.bounds, afterScreenUpdates: true)
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return image
}

使用平移、旋转和捏合手势编辑后如何保存 UIImage

How to save UIImage after Editing with Pan, Rotate and Pinch Gesture

core-image

uiimage

ios

uigraphicscontext

swift