NSImage to Base64

Question

I need to create a base64 string representation of an NSImage cocoa object. What\'s the best way of handling this, apple documentation seems to be a little short on the subj

Answer 1

Swift 4

extension NSImage {
    var base64String: String? {
        guard let rep = NSBitmapImageRep(
            bitmapDataPlanes: nil,
            pixelsWide: Int(size.width),
            pixelsHigh: Int(size.height),
            bitsPerSample: 8,
            samplesPerPixel: 4,
            hasAlpha: true,
            isPlanar: false,
            colorSpaceName: .calibratedRGB,
            bytesPerRow: 0,
            bitsPerPixel: 0
            ) else {
                print("Couldn't create bitmap representation")
                return nil
        }

        NSGraphicsContext.saveGraphicsState()
        NSGraphicsContext.current = NSGraphicsContext(bitmapImageRep: rep)
        draw(at: NSZeroPoint, from: NSZeroRect, operation: .sourceOver, fraction: 1.0)
        NSGraphicsContext.restoreGraphicsState()

        guard let data = rep.representation(using: NSBitmapImageRep.FileType.png, properties: [NSBitmapImageRep.PropertyKey.compressionFactor: 1.0]) else {
            print("Couldn't create PNG")
            return nil
        }

        // With prefix
        // return "data:image/png;base64,\(data.base64EncodedString(options: []))" 
        // Without prefix
        return data.base64EncodedString(options: []))
    }
}