How can I color a UIImage in Swift?

Question

I have an image called arrowWhite. I want to colour this image to black.

func attachDropDownArrow() -> NSMutableAttributedString {
    let im         


        

Answer 1

I ended up with this because other answers either lose resolution or work with UIImageView, not UIImage, or contain unnecessary actions:

Swift 3

extension UIImage {

    public func maskWithColor(color: UIColor) -> UIImage {

        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
        let context = UIGraphicsGetCurrentContext()!

        let rect = CGRect(origin: CGPoint.zero, size: size)

        color.setFill()
        self.draw(in: rect)

        context.setBlendMode(.sourceIn)
        context.fill(rect)

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

}

Answer 2

I found the solution by H R to be most helpful but adapted it slightly for Swift 3

extension UIImage {

    func maskWithColor( color:UIColor) -> UIImage {

         UIGraphicsBeginImageContextWithOptions(self.size, false, UIScreen.main.scale)
         let context = UIGraphicsGetCurrentContext()!

         color.setFill()

         context.translateBy(x: 0, y: self.size.height)
         context.scaleBy(x: 1.0, y: -1.0)

         let rect = CGRect(x: 0.0, y: 0.0, width: self.size.width, height: self.size.height)
         context.draw(self.cgImage!, in: rect)

         context.setBlendMode(CGBlendMode.sourceIn)
         context.addRect(rect)
         context.drawPath(using: CGPathDrawingMode.fill)

         let coloredImage = UIGraphicsGetImageFromCurrentImageContext()
         UIGraphicsEndImageContext()

         return coloredImage!
    }
}

This takes into consideration scale and also does not produce a lower res image like some other solutions. Usage :

image = image.maskWithColor(color: .green )

Answer 3

Add this extension in your code and change image color in storyboard itself.

Swift 4 & 5:

extension UIImageView {
    @IBInspectable
    var changeColor: UIColor? {
        get {
            let color = UIColor(cgColor: layer.borderColor!);
            return color
        }
        set {
            let templateImage = self.image?.withRenderingMode(.alwaysTemplate)
            self.image = templateImage
            self.tintColor = newValue
        }
    }
}

---

Storyboard Preview:

Answer 4

Swift 3

21 June 2017

I use CALayer to mask the given image with Alpha Channel

import Foundation


extension UIImage {

    func maskWithColor(color: UIColor) -> UIImage? {
    
        let maskLayer = CALayer()
        maskLayer.bounds = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        maskLayer.backgroundColor = color.cgColor
        maskLayer.doMask(by: self)
        let maskImage = maskLayer.toImage()
        return maskImage
    }

}


extension CALayer {
    func doMask(by imageMask: UIImage) {
        let maskLayer = CAShapeLayer()
        maskLayer.bounds = CGRect(x: 0, y: 0, width: imageMask.size.width, height: imageMask.size.height)
        bounds = maskLayer.bounds
        maskLayer.contents = imageMask.cgImage
        maskLayer.frame = CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height)
        mask = maskLayer
    }

    func toImage() -> UIImage?
    {
        UIGraphicsBeginImageContextWithOptions(bounds.size,
                                               isOpaque,
                                               UIScreen.main.scale)
        guard let context = UIGraphicsGetCurrentContext() else {
            UIGraphicsEndImageContext()
            return nil
        }
        render(in: context)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

Answer 5

Swift 3 version with scale and Orientation from @kuzdu answer

extension UIImage {

    func mask(_ color: UIColor) -> UIImage? {
        let maskImage = cgImage!

        let width = (cgImage?.width)!
        let height = (cgImage?.height)!
        let bounds = CGRect(x: 0, y: 0, width: width, height: height)

        let colorSpace = CGColorSpaceCreateDeviceRGB()
        let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedLast.rawValue)
        let context = CGContext(data: nil, width: Int(width), height: Int(height), bitsPerComponent: 8, bytesPerRow: 0, space: colorSpace, bitmapInfo: bitmapInfo.rawValue)!

        context.clip(to: bounds, mask: maskImage)
        context.setFillColor(color.cgColor)
        context.fill(bounds)

        if let cgImage = context.makeImage() {
            let coloredImage = UIImage.init(cgImage: cgImage, scale: scale, orientation: imageOrientation)
            return coloredImage
        } else {
            return nil
        }
    }
}

Answer 6

Here is swift 3 version of H R's solution.

func overlayImage(color: UIColor) -> UIImage? {
    UIGraphicsBeginImageContextWithOptions(self.size, false, UIScreen.main.scale)
    let context = UIGraphicsGetCurrentContext()

    color.setFill()

    context!.translateBy(x: 0, y: self.size.height)
    context!.scaleBy(x: 1.0, y: -1.0)

    context!.setBlendMode(CGBlendMode.colorBurn)
    let rect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
    context!.draw(self.cgImage!, in: rect)

    context!.setBlendMode(CGBlendMode.sourceIn)
    context!.addRect(rect)
    context!.drawPath(using: CGPathDrawingMode.fill)

    let coloredImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return coloredImage
}