Add padding/margin at a image!

ImageInsets.swift

import UIKit

extension UIImage {
  func imageWithInsets(insetDimen: CGFloat) -> UIImage {
    return imageWithInset(UIEdgeInsets(top: insetDimen, left: insetDimen, bottom: insetDimen, right: insetDimen))
  }
  
  func imageWithInset(insets: UIEdgeInsets) -> UIImage {
    UIGraphicsBeginImageContextWithOptions(
      CGSizeMake(self.size.width + insets.left + insets.right,
        self.size.height + insets.top + insets.bottom), false, self.scale)
    let origin = CGPoint(x: insets.left, y: insets.top)
    self.drawAtPoint(origin)
    let imageWithInsets = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return imageWithInsets
  }
  
}

Ensure to copy the renderingMode of the original image.

extension UIImage {
    func imageWithInsets(insetDimen: CGFloat) -> UIImage {
        return imageWithInset(insets: UIEdgeInsets(top: insetDimen, left: insetDimen, bottom: insetDimen, right: insetDimen))
    }
    
    func imageWithInset(insets: UIEdgeInsets) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(
            CGSize(width: self.size.width + insets.left + insets.right,
                   height: self.size.height + insets.top + insets.bottom), false, self.scale)
        let origin = CGPoint(x: insets.left, y: insets.top)
        self.draw(at: origin)
        let imageWithInsets = UIGraphicsGetImageFromCurrentImageContext()?.withRenderingMode(self.renderingMode)
        UIGraphicsEndImageContext()
        return imageWithInsets!
    }
    
}

added self.scale for others screens

extension UIImage {

    func withInset(_ insets: UIEdgeInsets) -> UIImage? {
        let cgSize = CGSize(width: self.size.width + insets.left * self.scale + insets.right * self.scale,
                            height: self.size.height + insets.top * self.scale + insets.bottom * self.scale)

        UIGraphicsBeginImageContextWithOptions(cgSize, false, self.scale)
        defer { UIGraphicsEndImageContext() }

        let origin = CGPoint(x: insets.left * self.scale, y: insets.top * self.scale)
        self.draw(at: origin)

        return UIGraphicsGetImageFromCurrentImageContext()?.withRenderingMode(self.renderingMode)
    }
}

Solution using new UIGraphicsImageRenderer Apple API. Battle-tested 🙂

extension UIImage {
    
    func image(insets: UIEdgeInsets) -> UIImage? {
        let targetSize = CGSize(width: self.size.width + insets.left + insets.right,
                                height: self.size.height + insets.top + insets.bottom)
        let targetOrigin = CGPoint(x: insets.left, y: insets.top)
        
        let format = UIGraphicsImageRendererFormat()
        format.scale = 1
        let renderer = UIGraphicsImageRenderer(size: targetSize, format: format)
        
        return renderer.image { _ in
            self.draw(in: CGRect(origin: targetOrigin, size: self.size))
        }
    }
}

@dterekhov you forgot about renderingMode and the correct scale. Here is a fully operational solution:

extension UIImage {
    
    func with(_ insets: UIEdgeInsets) -> UIImage {
        let targetWidth = size.width + insets.left + insets.right
        let targetHeight = size.height + insets.top + insets.bottom
        let targetSize = CGSize(width: targetWidth, height: targetHeight)
        let targetOrigin = CGPoint(x: insets.left, y: insets.top)
        let format = UIGraphicsImageRendererFormat()
        format.scale = scale
        let renderer = UIGraphicsImageRenderer(size: targetSize, format: format)
        return renderer.image { _ in
            draw(in: CGRect(origin: targetOrigin, size: size))
        }.withRenderingMode(renderingMode)
    }
    
}

@dterekhov you forgot about renderingMode and the correct scale. Here is a fully operational solution:

extension UIImage {
    
    func with(_ insets: UIEdgeInsets) -> UIImage {
        let targetWidth = size.width + insets.left + insets.right
        let targetHeight = size.height + insets.top + insets.bottom
        let targetSize = CGSize(width: targetWidth, height: targetHeight)
        let targetOrigin = CGPoint(x: insets.left, y: insets.top)
        let format = UIGraphicsImageRendererFormat()
        format.scale = scale
        let renderer = UIGraphicsImageRenderer(size: targetSize, format: format)
        return renderer.image { _ in
            draw(in: CGRect(origin: targetOrigin, size: size))
        }.withRenderingMode(renderingMode)
    }
    
}

Thank you! It very useful.