NSImage to NSData as PNG Swift

Question

I am writing a Mac app based on an iOS app. The code below converts a UIImage to NSData to upload to Parse.com.

I would like to do the same for Mac but I do not seem to be able to convert it to NSData. What should I be doing?

Thanks

var image = UIImage(named: "SmudgeInc")

let imageData = UIImagePNGRepresentation(image)

let imageFile = PFFile(name:"image.png", data:imageData)

Answer 1

You can use the NSImage property TIFFRepresentation to convert your NSImage to NSData:

let imageData = yourImage.TIFFRepresentation

If you need to save your image data to a PNG file you can use NSBitmapImageRep(data:) and representationUsingType to create an extension to help you convert Data to PNG format:

Update: Xcode 11 • Swift 5.1

extension NSBitmapImageRep {
    var png: Data? { representation(using: .png, properties: [:]) }
}
extension Data {
    var bitmap: NSBitmapImageRep? { NSBitmapImageRep(data: self) }
}
extension NSImage {
    var png: Data? { tiffRepresentation?.bitmap?.png }
}

---

usage

let picture = NSImage(contentsOf: URL(string: "https://i.stack.imgur.com/Xs4RX.jpg")!)!

let imageURL = FileManager.default.urls(for: .desktopDirectory, in: .userDomainMask).first!.appendingPathComponent("image.png")
if let png = picture.png {
    do {
        try png.write(to: imageURL)
        print("PNG image saved")
    } catch {
        print(error)
    }
}