enumRawValue.swift

public enum FilterType: String, BaseSelectionType, CaseIterable {
    case colorDocument = "Color Document"
    case blackAndWhite = "Black And White"
    case colorPhoto = "Color Photo"
    case greyscale = "Greyscale"    
}

// getting the raw value
FilterType.allCases.map({ (type) -> String in
    print type.rawValue
})
//prints Color Document
//prints Black And White
//prints Color Photo
//prints Greyscale

// raw value initialization
let type = FilterType(rawValue: "Color Document")

print(type.rawValue)
//prints Color Document