Detect Image Colors

Extracts 4 main colors from an image: primary, secondary, detail and background.

Code Usage

1. Grab the files which name begins with "CD" and copy them to your Xcode Swift project.

2. Optional: tweak CDSettings variables

3. Create color candidates from image:

let colorCandidates = image.getColorCandidates()

Demo Application

Download or clone the project, open in Xcode, build (Swift 4, Xcode 9).

You can drop a new image on the image view and tweak the sliders to find values you like for the thresholds and ratios.

Playground

A Playground is also included for demo purposes.

Public methods and properties

NSImage extension:

func getColorCandidates() -> ColorCandidates?
var isImageSquared: Bool

NSColor extension:

func isNear(of: NSColor) -> Bool
func lighter(threshold: CGFloat = default, ratio: CGFloat = default) -> NSColor
func darker(threshold: CGFloat = default, ratio: CGFloat = default) -> NSColor
func applyingSaturation(minimum: CGFloat) -> NSColor
func contrastsWith(_: NSColor) -> Bool
var isMostlyBlackOrWhite: Bool
var isMostlyDarkColor: Bool
func componentsCSS() -> (alpha: String, red: String, green: String, blue: String, css: String, clean: String)?
func componentsNSC() -> (alpha: CGFloat, red: CGFloat, green: CGFloat, blue: CGFloat)?
func componentsRGB() -> (alpha: Int, red: Int, green: Int, blue: Int)?
func componentsHUE() -> (alpha: CGFloat, hue: CGFloat, saturation: CGFloat, brightness: CGFloat)?

ColorCandidates struct:

var primary: NSColor?
var secondary: NSColor?
var detail: NSColor?
var background: NSColor?
var backgroundIsDark: Bool?
var backgroundIsBlackOrWhite: Bool?
var JSONData: Data

CDSettings class:

var thresholdMinimumPercentage: Double
var thresholdMinimumSaturation: CGFloat
var thresholdNoiseTolerance: Int
var thresholdFloorBrightness: CGFloat
var thresholdCeilingBrightness: CGFloat
var thresholdDistinctColor: CGFloat
var thresholdGrey: CGFloat
var minThresholdWhite: CGFloat
var maxThresholdBlack: CGFloat
var lighterRatio: CGFloat
var darkerRatio: CGFloat
var contrastRatio: CGFloat
var luminanceAddedWeight: CGFloat
var YUVRedRatio: CGFloat
var YUVGreenRatio: CGFloat
var YUVBlueRatio: CGFloat
var detectorDistanceFromLeftEdge: Int
var detectorResolution: Int
var ensureContrastedColorCandidates: Bool

Todo

Suggestions and contributions are welcomed!

• Improve detector accuracy

• Improve detector speed

• Improve resize image method

• Make it iOS compatible

• Make a better demo app

History

This started has a translation from Objective-C to Swift of Color Art by Panic Software, from their 2011 blog article.

Then after lots of changes and optimizations (and a few regressions) I added new features like color names and customizable parameters.

I've also made a simple demo app to test the color detection.

Disclaimer

This is only a programming exercise, to explore possibilities - this is not for production.

If you're looking for performance in color detection, see my Swift 2 fork of Indragie Karunaratne's DominantColor instead.

Licence

MIT but you have to refer to this page and to Panic's repository somewhere visible.