ios 如何合并两个 UIImages？
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How to merge two UIImages?
提问by Luca Alberto
I am trying to merge two different images and create a new one. This is the way I would like to do:
I have this image (A): 
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）：
It's a PNG image and I would like to merge this one with another image (B) which I took from the phone to create something like this:
这是一张 PNG 图像，我想将此图像与我从手机中获取的另一张图像 (B) 合并以创建如下内容：
I need a function who merge A with B creating C. The size must remain from the A image and the image B should auto adapt the size to fit into the polaroid (A). Is it possible to do that? Thank for your help!
我需要一个将 A 与 B 合并创建 C 的函数。大小必须与 A 图像保持一致，图像 B 应自动调整大小以适应宝丽来 (A)。有可能这样做吗？感谢您的帮助！
UPDATEJust one thing, the image (A) is a square and the image i took is a 16:9, how can i fix that?? If i use your function the image (B) that i took become stretched!
更新只有一件事，图像 (A) 是一个正方形，而我拍摄的图像是 16:9，我该如何解决？如果我使用你的功能，我拍摄的图像（B）就会被拉伸！
回答by Pallavi Konda
Hope this may help you,
希望这可以帮助你，
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()
All the Best :)
祝一切顺利 ：）
回答by Svitlana
This way the overlay picture will be much cleaner
这样叠加图片会更干净
class func mergeImages(imageView: UIImageView) -> UIImage {
UIGraphicsBeginImageContextWithOptions(imageView.frame.size, false, 0.0)
imageView.superview!.layer.renderInContext(UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
回答by budidino
Swift 4UIImageextension that enables easy image merging / overlaying.
Swift 4UIImage扩展，可以轻松合并/覆盖图像。
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
}
}
回答by Glen
Swift 5: Extension for UIImage
Swift 5：扩展 UIImage
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
}
}
回答by FrankByte.com
Slightly modified version of answer by budidino. This implementation also handles negative posX and posY correctly.
budidino 对答案稍作修改。此实现还正确处理负 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
}
}
回答by iLearner
Objective C version of this solution with top image re-centered logic :
此解决方案的目标 C 版本具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;
}
回答by Milez
The upvoted answer stretchesthe background image changing its ratio. The solution below fixes that by rendering the image from a UIView that contains the two image views as subviews.
赞成的答案会拉伸背景图像，改变其比例。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 渲染图像来解决这个问题。
ANSWER YOU ARE LOOKING FOR (Swift 4):
您正在寻找的答案（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
}
The returned image data doubles the size of the image, so set the size of the views at half the desired size.
返回的图像数据使图像的大小加倍，因此将视图的大小设置为所需大小的一半。
- EXAMPLE: I wanted the width and height of the image to be 612, so I set the view frames width and height to 306)// Enjoy :)
- 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 :)
