Creating a thumbnail from UIImage using CGImageSourceCreateThumbnailAtIndex

Question

I want to use the function CGImageSourceCreateThumbnailAtIndex to create a thumbnail from an UIImage. All I have is the UIImage itself. Th

Answer 1

Swift 4 code

let imageData = UIImagePNGRepresentation(image)!
let options = [
    kCGImageSourceCreateThumbnailWithTransform: true,
    kCGImageSourceCreateThumbnailFromImageAlways: true,
    kCGImageSourceThumbnailMaxPixelSize: 300] as CFDictionary
let source = CGImageSourceCreateWithData(imageData, nil)!
let imageReference = CGImageSourceCreateThumbnailAtIndex(source, 0, options)!
let thumbnail = UIImage(cgImage: imageReference)