Fix issue of considering semi-transparent pixels. Also consider the whole image for background color instead of just a margin

Author: jathu

Diff for: README.md

@@ -1,6 +1,6 @@
 # UIImageColors
 
-iTunes style color fetcher for UIImage. This is an *almost* identical port of [Panic's OS X ColorArt](https://github.com/panicinc/ColorArt/) for iOS Swift.
+iTunes style color fetcher for UIImage. This is based on [Panic's OS X ColorArt](https://github.com/panicinc/ColorArt/) for iOS Swift.
 
 In other words, it fetches the most dominant and prominent colors.
 

Diff for: Sources/UIImageColors.swift

@@ -148,12 +148,12 @@ extension UIImage {
         var result = UIImageColors()
 
         let cgImage = self.resizeForUIImageColors(newSize: scaleDownSize).cgImage!
-        let width = cgImage.width
-        let height = cgImage.height
+        let width: Int = cgImage.width
+        let height: Int = cgImage.height
+        
+        let blackColor = UIColor(red: 0, green: 0, blue: 0, alpha: 1)
+        let whiteColor = UIColor(red: 1, green: 1, blue: 1, alpha: 1)
 
-        let bytesPerPixel: Int = 4
-        let bytesPerRow: Int = width * bytesPerPixel
-        let bitsPerComponent: Int = 8
         let randomColorsThreshold = Int(CGFloat(height)*0.01)
         let sortedColorComparator: Comparator = { (main, other) -> ComparisonResult in
             let m = main as! PCCountedColor, o = other as! PCCountedColor
@@ -165,50 +165,34 @@ extension UIImage {
                 return ComparisonResult.orderedAscending
             }
         }
-        let blackColor = UIColor(red: 0, green: 0, blue: 0, alpha: 1)
-        let whiteColor = UIColor(red: 1, green: 1, blue: 1, alpha: 1)
-        
-        let colorSpace = CGColorSpaceCreateDeviceRGB()
-        let raw = malloc(bytesPerRow * height)
-        defer {
-            free(raw)
-        }
-        let bitmapInfo = CGImageAlphaInfo.premultipliedFirst.rawValue
-        guard let ctx = CGContext(data: raw, width: width, height: height, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow, space: colorSpace, bitmapInfo: bitmapInfo) else {
-            fatalError("UIImageColors.getColors failed: could not create CGBitmapContext")
+
+        guard let data = CFDataGetBytePtr(cgImage.dataProvider!.data) else {
+            fatalError("UIImageColors.getColors failed: could not get cgImage data")
         }
-        let drawingRect = CGRect(x: 0, y: 0, width: CGFloat(width), height: CGFloat(height))
-        ctx.draw(cgImage, in: drawingRect)
 
-        let data = ctx.data?.assumingMemoryBound(to: UInt8.self)
-        
-        let leftEdgeColors = NSCountedSet(capacity: height)
+        // Filter out and collect pixels from image
         let imageColors = NSCountedSet(capacity: width * height)
 
         for x in 0..<width {
             for y in 0..<height {
-                let pixel = ((width * y) + x) * bytesPerPixel
-                let color = UIColor(
-                    red: CGFloat((data?[pixel+1])!)/255,
-                    green: CGFloat((data?[pixel+2])!)/255,
-                    blue: CGFloat((data?[pixel+3])!)/255,
-                    alpha: 1
-                )
-                
-                // A lot of images have white or black edges from crops, so ignore the first few pixels
-                if 5 <= x && x <= 10 {
-                    leftEdgeColors.add(color)
+                let pixel: Int = ((width * y) + x) * 4
+                // Only consider pixels with 50% opacity or higher
+                if 127 <= data[pixel+3] {
+                    imageColors.add(UIColor(
+                        red: CGFloat(data[pixel+2])/255,
+                        green: CGFloat(data[pixel+1])/255,
+                        blue: CGFloat(data[pixel])/255,
+                        alpha: 1.0
+                    ))
                 }
-                
-                imageColors.add(color)
             }
         }
 
         // Get background color
-        var enumerator = leftEdgeColors.objectEnumerator()
-        var sortedColors = NSMutableArray(capacity: leftEdgeColors.count)
+        var enumerator = imageColors.objectEnumerator()
+        var sortedColors = NSMutableArray(capacity: imageColors.count)
         while let kolor = enumerator.nextObject() as? UIColor {
-            let colorCount = leftEdgeColors.count(for: kolor)
+            let colorCount = imageColors.count(for: kolor)
             if randomColorsThreshold < colorCount  {
                 sortedColors.add(PCCountedColor(color: kolor, count: colorCount))
             }

Diff for: Supporting Files/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.0</string>
+	<string>1.3.0</string>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 	<key>NSPrincipalClass</key>

Diff for: UIImageColors.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |spec|
   spec.name        = "UIImageColors"
-  spec.version     = "1.2.1"
+  spec.version     = "1.3.0"
   spec.license     = "MIT"
   spec.summary     = "iTunes style color fetcher for UIImage."
   spec.homepage    = "https://github.com/jathu/UIImageColors"

Diff for: UIImageColorsPlayground.playground/Contents.swift

@@ -7,18 +7,18 @@ import UIImageColors
 PlaygroundPage.current.needsIndefiniteExecution = true
 
 let Albums: [Album] = [
-    Album(albumFile: "OK Computer.png", albumName: "OK Computer", artistName: "Radiohead", year: 1997),
-    Album(albumFile: "Nothing Was the Same.png", albumName: "Nothing Was the Same", artistName: "Drake", year: 2013),
-    Album(albumFile: "My Beautiful Dark Twisted Fantasy.png", albumName: "My Beautiful Dark Twisted Fantasy", artistName: "Kanye West", year: 2010),
-    Album(albumFile: "Kind of Blue.png", albumName: "Kind of Blue", artistName: "Miles Davis", year: 1959),
-    Album(albumFile: "If You're Reading This It's Too Late.png", albumName: "If You're Reading This It's Too Late", artistName: "Drake", year: 2015),
-    Album(albumFile: "New Morning.png", albumName: "New Morning", artistName: "Bob Dylan", year: 1970),
-    Album(albumFile: "Since I Left You.png", albumName: "Since I Left You", artistName: "The Avalanches", year: 2000),
-    Album(albumFile: "Random Access Memories.png", albumName: "Random Access Memories", artistName: "Daft Punk", year: 2013),
-    Album(albumFile: "The Eraser.png", albumName: "The Eraser", artistName: "Thome Yorke", year: 2006),
-    Album(albumFile: "Operation Doomsday.png", albumName: "Operation Doomsday", artistName: "MF Doom", year: 1999),
-    Album(albumFile: "Cupid Deluxe.png", albumName: "Cupid Deluxe", artistName: "Blood Orange", year: 2013),
-    Album(albumFile: "Black on Both Sides.png", albumName: "Black on Both Sides", artistName: "Mos Def", year: 1999)
+    Album(albumFile: "df.png", albumName: "My Beautiful Dark Twisted Fantasy", artistName: "Kanye West", year: 2010),
+    Album(albumFile: "nw.jpg", albumName: "Nothing Was the Same", artistName: "Drake", year: 2013),
+    Album(albumFile: "ok.png", albumName: "OK Computer", artistName: "Radiohead", year: 1997),
+    Album(albumFile: "yz.jpg", albumName: "Yeezus", artistName: "Kanye West", year: 2013),
+    Album(albumFile: "ab.jpg", albumName: "Ágætis byrjun", artistName: "Sigur Rós", year: 1999),
+    Album(albumFile: "cd.jpg", albumName: "Cupid Deluxe", artistName: "Blood Orange", year: 2013),
+    Album(albumFile: "ed.jpg", albumName: "Endtroducing.....", artistName: "DJ Shadow", year: 1996),
+    Album(albumFile: "dj.jpg", albumName: "Duke Ellington & John Coltrane", artistName: "Duke Ellington & John Coltrane", year: 1963),
+    Album(albumFile: "ph.jpg", albumName: "Purple Haze", artistName: "Cam'ron", year: 2004),
+    Album(albumFile: "rm.png", albumName: "Random Access Memories", artistName: "Daft Punk", year: 2013),
+    Album(albumFile: "sk.jpg", albumName: "Skream!", artistName: "Skream", year: 2006),
+    Album(albumFile: "b6.jpg", albumName: "Barter 6", artistName: "Young Thug", year: 2015)
 ]
 
 func makeBox(_ asynchronous: Bool, completionHandler: @escaping (UIView) -> Void) {
@@ -30,7 +30,7 @@ func makeBox(_ asynchronous: Bool, completionHandler: @escaping (UIView) -> Void
         let c = Container(album: Albums[Int(i)])
         c.frame.origin = CGPoint(x: sample.frame.width*(i.truncatingRemainder(dividingBy: 2)), y: sample.frame.height*floor(i/2))
         box.addSubview(c)
-
+        
         if asynchronous {
             c.albumImageView.image!.getColors { colors in
                 c.backgroundColor = colors.backgroundColor
@@ -55,7 +55,7 @@ func makeBox(_ asynchronous: Bool, completionHandler: @escaping (UIView) -> Void
 }
 
 // Make a box of albums
-makeBox(true) { box in
+makeBox(false) { box in
     box.alpha = 1
     PlaygroundPage.current.finishExecution()
 }

Diff for: UIImageColorsPlayground.playground/Resources/Black on Both Sides.png

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-<playground version='5.0' target-platform='ios' last-migration='0800'>
+<playground version='5.0' target-platform='ios' executeOnSourceChanges='false' last-migration='0800'>
     <timeline fileName='timeline.xctimeline'/>
 </playground>

Diff for: UIImageColorsPlayground.playground/Resources/Cupid Deluxe.png

@@ -3,37 +3,37 @@
    version = "3.0">
    <TimelineItems>
       <LoggerValueHistoryTimelineItem
-         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=3117&amp;EndingColumnNumber=23&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=497787292.509668"
+         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=2917&amp;EndingColumnNumber=23&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=515104523.006536"
          selectedRepresentationIndex = "0"
          shouldTrackSuperviewWidth = "NO">
       </LoggerValueHistoryTimelineItem>
       <LoggerValueHistoryTimelineItem
-         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=3117&amp;EndingColumnNumber=20&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=497787292.509811"
+         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=2917&amp;EndingColumnNumber=20&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=515104523.00672"
          selectedRepresentationIndex = "0"
          shouldTrackSuperviewWidth = "NO">
       </LoggerValueHistoryTimelineItem>
       <LoggerValueHistoryTimelineItem
-         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=3117&amp;EndingColumnNumber=19&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=497787292.509913"
+         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=2917&amp;EndingColumnNumber=19&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=515104523.00685"
          selectedRepresentationIndex = "0"
          shouldTrackSuperviewWidth = "NO">
       </LoggerValueHistoryTimelineItem>
       <LoggerValueHistoryTimelineItem
-         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=3117&amp;EndingColumnNumber=22&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=497787292.51001"
+         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=2917&amp;EndingColumnNumber=22&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=515104523.006985"
          selectedRepresentationIndex = "0"
          shouldTrackSuperviewWidth = "NO">
       </LoggerValueHistoryTimelineItem>
       <LoggerValueHistoryTimelineItem
-         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=3117&amp;EndingColumnNumber=3&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=497787292.510102"
+         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=2917&amp;EndingColumnNumber=3&amp;EndingLineNumber=59&amp;StartingColumnNumber=1&amp;StartingLineNumber=59&amp;Timestamp=515104523.007109"
          selectedRepresentationIndex = "0"
          shouldTrackSuperviewWidth = "NO">
       </LoggerValueHistoryTimelineItem>
       <LoggerValueHistoryTimelineItem
-         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=3117&amp;EndingColumnNumber=8&amp;EndingLineNumber=59&amp;StartingColumnNumber=5&amp;StartingLineNumber=59&amp;Timestamp=497787292.510192"
+         documentLocation = "#CharacterRangeLen=0&amp;CharacterRangeLoc=2917&amp;EndingColumnNumber=8&amp;EndingLineNumber=59&amp;StartingColumnNumber=5&amp;StartingLineNumber=59&amp;Timestamp=515104523.007231"
          selectedRepresentationIndex = "0"
          shouldTrackSuperviewWidth = "NO">
       </LoggerValueHistoryTimelineItem>
       <LoggerValueHistoryTimelineItem
-         documentLocation = "#CharacterRangeLen=3&amp;CharacterRangeLoc=3113&amp;EndingColumnNumber=8&amp;EndingLineNumber=58&amp;StartingColumnNumber=5&amp;StartingLineNumber=58&amp;Timestamp=497787293.750125"
+         documentLocation = "#CharacterRangeLen=3&amp;CharacterRangeLoc=2913&amp;EndingColumnNumber=8&amp;EndingLineNumber=58&amp;StartingColumnNumber=5&amp;StartingLineNumber=58&amp;Timestamp=515104523.007466"
          lockedSize = "{546, 444}"
          selectedRepresentationIndex = "0"
          shouldTrackSuperviewWidth = "NO">