我已经看到人们在Objective- C中做到这一点,但是我很快就遇到了麻烦。我已经从图片中获得了像素的颜色,但是现在我需要分别获取红色,绿色和蓝色的值。这是我所拥有的(h,w和rgb是整数,image.getPixelColor(CGPoint)返回UIColor):
xArry[h][w][rgb] = image.getPixelColor(CGPoint(x: w, y: h))
如何将此UIColor更改为红色,绿色和蓝色值?谢谢!
您可以将UIColor转换为CIColor,然后从中提取颜色成分,如下所示:
更新: Xcode 8.3.2•Swift 3.1
extension UIColor { var coreImageColor: CIColor { return CIColor(color: self) } var components: (red: CGFloat, green: CGFloat, blue: CGFloat, alpha: CGFloat) { let coreImageColor = self.coreImageColor return (coreImageColor.red, coreImageColor.green, coreImageColor.blue, coreImageColor.alpha) } }
用法:
let myColor = UIColor(red: 0.5, green: 1, blue: 0.25, alpha: 0.5) let myCIColor = myColor.coreImageColor let greencomponent = myColor.components.green let myColorComponents = myColor.components print(myColorComponents.red) // 0.5 print(myColorComponents.green) // 1.0 print(myColorComponents.blue) // 0.25 print(myColorComponents.alpha) // 0.5
您还可以使用函数getRed()并创建一个扩展来提取组件,如下所示,但结果将是可选的:
extension UIColor { var components: (red: CGFloat, green: CGFloat, blue: CGFloat, alpha: CGFloat)? { var r: CGFloat = 0, g: CGFloat = 0, b: CGFloat = 0, a: CGFloat = 0 return getRed(&r, green: &g, blue: &b, alpha: &a) ? (r,g,b,a) : nil } }
用法
let myColor = UIColor(red: 0.5, green: 1, blue: 0.25, alpha: 0.5) if let myColorComponents = myColor.components { print(myColorComponents.red) // 0.5 print(myColorComponents.green) // 1.0 print(myColorComponents.blue) // 0.25 print(myColorComponents.alpha) // 0.5 }