How to save PNG file from NSImage (retina issues)

Question

I\'m doing some operations on images and after I\'m done, I want to save the image as PNG on disk. I\'m doing the following:

+ (void)saveImage:(NSImage *)ima         


        

Answer 1

Just incase anyone stumbles up on this thread. Here is certainly flawed solution that does the job of saving image at 1x size (image.size) regardless of device in swift

public func writeToFile(path: String, atomically: Bool = true) -> Bool{

    let bitmap = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: Int(self.size.width), pixelsHigh: Int(self.size.height), bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: NSDeviceRGBColorSpace, bytesPerRow: 0, bitsPerPixel: 0)!
    bitmap.size = self.size

    NSGraphicsContext.saveGraphicsState()

    NSGraphicsContext.setCurrentContext(NSGraphicsContext(bitmapImageRep: bitmap))
    self.drawAtPoint(CGPoint.zero, fromRect: NSRect.zero, operation: NSCompositingOperation.CompositeSourceOver, fraction: 1.0)
    NSGraphicsContext.restoreGraphicsState()

    if let imagePGNData = bitmap.representationUsingType(NSBitmapImageFileType.NSPNGFileType, properties: [NSImageCompressionFactor: 1.0]) {
        return imagePGNData.writeToFile((path as NSString).stringByStandardizingPath, atomically: atomically)
    } else {
        return false
    }
}