How to merge two UIImages?

Question

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):

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:

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!

UPDATE Just 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!

Solution 1

Hope this may help you,

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 :)

Solution 2

Swift 5: Extension for 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
  }
}

Solution 3

Swift 4 UIImage extension that enables easy image merging / overlaying.

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
  }

}

Solution 4

This way the overlay picture will be much cleaner:

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

Solution 5

Objective C version of this solution with top image re-centered logic :

-(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;
}

View more solutions

Comments

[Pallavi Konda]

can you try to change the alpha value to 1.0 or 0.1.. am not sure about the value

[Aleksander Grzyb]

You can use different version of drawInRect which is not taking blending option as argument which is topImage!.drawInRect(CGRectMake(xPosition, yPosition, topImage!.size.width, topImage!.size.height))

[Luca Alberto]

just 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!

[iLearner]

Whomsoever has down-voted my answer, could you also take a moment and add your comment why its down-voted, so that I will also get to know what was wrong with my answer.

[Milez]

@luca-alberto, here is your solution!!

[OwlOCR]

Thanks this is a nice one, but it does not handle negative posX or posY correctly. I'll add an answer that takes them into account.

[Zahurafzal Mirza]

I used this and generated a base64 string of the new image. and its resulting in a blank image. I checked it on codebeautify.org/base64-to-image-converter#. The image results in a blank white image. What i am trying to do is merge two image parallel to each other. Can someone help me out please ?

[Ilesh P]

Problem: I got with space on top, bottom when UIImageView have Frame(10,10, width, height) Solution: Add UIImageView into the view so it will become the Frame(0, 0, width, height) and Fixed the white space top and bottom.