如何合并两个 UIImage？

Question

我正在尝试合并两个不同的图像并创建一个新图像。这是我想做的方式： 我有这张图片（A）：

这是一张 PNG 图片，我想将这张图片与我从手机中获取的另一张图片 (B) 合并，以创建类似这样的图片：

我需要一个将 A 与 B 合并创建 C 的函数。尺寸必须与 A 图像保持一致，并且图像 B 应自动调整尺寸以适应宝丽来 (A)。有可能这样做吗？感谢您的帮助！

更新 只是一件事，图像（A）是正方形，我拍摄的图像是 16:9，我该如何解决？如果我使用你的函数，我拍摄的图像 (B) 就会被拉伸！

Answer 1

希望对你有帮助，

var bottomImage = UIImage(named: "bottom.png")
var topImage = UIImage(named: "top.png")

var size = CGSize(width: 300, height: 300)
UIGraphicsBeginImageContext(size)

let areaSize = CGRect(x: 0, y: 0, width: size.width, height: size.height)
bottomImage!.draw(in: areaSize)

topImage!.draw(in: areaSize, blendMode: .normal, alpha: 0.8)

var newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()

一切顺利:)

Answer 2

这样叠加的图片会干净很多：

class func mergeImages(imageView: UIImageView) -> UIImage {
    UIGraphicsBeginImageContextWithOptions(imageView.frame.size, false, 0.0)
    imageView.superview!.layer.renderInContext(UIGraphicsGetCurrentContext()!)
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    
    return image 
}

Answer 3

此解决方案的 Objective C 版本，带有顶部图像重新居中逻辑：

-(UIImage *)getImageInclosedWithinAnotherImage
{
    float innerImageSize = 20;
    UIImage *finalImage;

    UIImage *outerImage = [UIImage imageNamed:@"OuterImage.png"];
    UIImage *innerImage = [UIImage imageNamed:@"InnerImage.png"];

    CGSize outerImageSize = CGSizeMake(40, 40); // Provide custom size or size of your actual image
    UIGraphicsBeginImageContext(outerImageSize);

    //calculate areaSize for re-centered inner image
    CGRect areSize = CGRectMake(((outerImageSize.width/2) - (innerImageSize/2)), ((outerImageSize.width/2) - (innerImageSize/2)), innerImageSize, innerImageSize);
    [outerImage drawInRect:CGRectMake(0, 0, outerImageSize.width, outerImageSize.height)];
    [innerImage drawInRect:areSize blendMode:kCGBlendModeNormal alpha:1.0];

    finalImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return finalImage;
}

Answer 4

Swift 4 UIImage 扩展，可轻松实现图像合并/叠加。

extension UIImage { 

  func overlayWith(image: UIImage, posX: CGFloat, posY: CGFloat) -> UIImage {
    let newWidth = size.width < posX + image.size.width ? posX + image.size.width : size.width
    let newHeight = size.height < posY + image.size.height ? posY + image.size.height : size.height
    let newSize = CGSize(width: newWidth, height: newHeight)

    UIGraphicsBeginImageContextWithOptions(newSize, false, 0.0)
    draw(in: CGRect(origin: CGPoint.zero, size: size))
    image.draw(in: CGRect(origin: CGPoint(x: posX, y: posY), size: image.size))
    let newImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()

    return newImage
  }

}

Answer 5

投票的答案拉伸背景图片改变了它的比例。下面的解决方案通过从包含两个图像视图作为子视图的 UIView 渲染图像来解决此问题。

回答您正在寻找的（Swift 4）：

func blendImages(_ img: UIImage,_ imgTwo: UIImage) -> Data? {
    let bottomImage = img
    let topImage = imgTwo

    let imgView = UIImageView(frame: CGRect(x: 0, y: 0, width: 306, height: 306))
    let imgView2 = UIImageView(frame: CGRect(x: 0, y: 0, width: 306, height: 306))

    // - Set Content mode to what you desire
    imgView.contentMode = .scaleAspectFill
    imgView2.contentMode = .scaleAspectFit

    // - Set Images
    imgView.image = bottomImage
    imgView2.image = topImage

    // - Create UIView
    let contentView = UIView(frame: CGRect(x: 0, y: 0, width: 306, height: 306))
    contentView.addSubview(imgView)
    contentView.addSubview(imgView2)

    // - Set Size
    let size = CGSize(width: 306, height: 306)

    // - Where the magic happens
    UIGraphicsBeginImageContextWithOptions(size, true, 0)

    contentView.drawHierarchy(in: contentView.bounds, afterScreenUpdates: true)

    guard let i = UIGraphicsGetImageFromCurrentImageContext(),
        let data = UIImageJPEGRepresentation(i, 1.0)
        else {return nil}

    UIGraphicsEndImageContext()

    return data
}

返回的图像数据使图像大小加倍，因此将视图大小设置为所需大小的一半。

• 示例：我希望图像的宽度和高度为 612，因此我将视图框架的宽度和高度设置为 306) // 享受 :)

Answer 6

budidino 对答案的略微修改版本。此实现还可以正确处理负 posX 和 posY。

extension UIImage {
    func overlayWith(image: UIImage, posX: CGFloat, posY: CGFloat) -> UIImage {
        let newWidth = posX < 0 ? abs(posX) + max(self.size.width, image.size.width) :
            size.width < posX + image.size.width ? posX + image.size.width : size.width
        let newHeight = posY < 0 ? abs(posY) + max(size.height, image.size.height) :
            size.height < posY + image.size.height ? posY + image.size.height : size.height
        let newSize = CGSize(width: newWidth, height: newHeight)

        UIGraphicsBeginImageContextWithOptions(newSize, false, 0.0)
        let originalPoint = CGPoint(x: posX < 0 ? abs(posX) : 0, y: posY < 0 ? abs(posY) : 0)
        self.draw(in: CGRect(origin: originalPoint, size: self.size))
        let overLayPoint = CGPoint(x: posX < 0 ? 0 : posX, y: posY < 0 ? 0 : posY)
        image.draw(in: CGRect(origin: overLayPoint, size: image.size))
        let newImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()

        return newImage
    }
}

Answer 7

Swift 5：UIImage 的扩展

extension UIImage {
  func mergeWith(topImage: UIImage) -> UIImage {
    let bottomImage = self

    UIGraphicsBeginImageContext(size)


    let areaSize = CGRect(x: 0, y: 0, width: bottomImage.size.width, height: bottomImage.size.height)
    bottomImage.draw(in: areaSize)

    topImage.draw(in: areaSize, blendMode: .normal, alpha: 1.0)

    let mergedImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()
    return mergedImage
  }
}