Difference between tiffRepresentation and bitmapRepresentation in terms of base64 string encoding? - swift

Question

I am trying to convert a NSImage into a base64 string encoding.
extension NSImage{
// Convert NSImage self to a string of base64 encoding
func getBase64String() -> String{
guard let tiffData = self.tiffRepresentation else {
printError("Failed to get tiffRepresentation")
exit(-1)
}
guard let bitmap: NSBitmapImageRep = NSBitmapImageRep(data: tiffData) else {
printError("Failed to get Bitmap representation from tiffRepresentation")
exit(-1)
}
guard let data = bitmap.representation(using: .png, properties: [:]) else {
printError("Failed to make image data with PNG type")
exit(-1)
}
let tiff_base64 = "data:image/png;base64," + tiffData.base64EncodedString()
let bitmap_base64 = "data:image/png;base64," + data.base64EncodedString()
return bitmap_base64
}
}
I used the result to embed images in a html file, and I found both tiff_base64 and bitmap_base64 work. However, the strings look kind of different of the same image.
Many examples of converting images into base64 on Stack Overflow are calling base64EncodedString() from a bitmap data. I am wondering does it really matter to use tiff_base64 or bitmap_base64?

Answer 1

TIFF and PNG are two different image formats. The use of base 64 is really irrelevant to your question.
First decide which image format you need (which depends on what you are doing with the result. Once you've decided whether you need your images represented as PNG or TIFF (or JPEG or any other supported format), then you apply the base64 encoding to that data.