swift图片颜色占比分析
代码语言：javascript复制extension UIImage {
func scaleTo(size: CGSize) -> UIImage? {
UIGraphicsBeginImageContextWithOptions(size, false, 1.0)
self.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
let newImg = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImg
}
/// 一张图颜色占比 取十种颜色
func colorRate() -> [Double] {
// 把 UIImage 转换成 CGImage Data
let provider = self.cgImage?.dataProvider
let pixeData = provider?.data
guard let pxData = pixeData else {
return []
}
guard let data = CFDataGetBytePtr(pxData) else {
return []
}
let dataLength = CFDataGetLength(pxData)
let numberOfColorComponents = 4 // R,G,B, and A
// 用来装 color ，key 为 R-G-B 字符串，value 为出现次数
var colors = [String: Double]()
var colorCount: Double = 0
var i = 0
while i < dataLength {
i = numberOfColorComponents
if data[i 3] != 0 {//非透明
colorCount = 1
let red = data[i]
let green = data[i 1]
let blue = data[i 2]
let result = "(red)-(green)-(blue)"
if !colors.keys.contains(result) {
colors[result] = 1
} else {
colors[result] = colors[result]! 1.0
}
}
}
let colorValues = colors.values.sorted { $0 > $1 }
var colorRates = [Double]()
for (index, item) in colorValues.enumerated() {
if index < 10 {
let rate = item / colorCount
colorRates.append(rate)
}
}
return colorRates
}
}
调用以上方法，终端输出： [0.3862848497311907, 0.093752754193718965, 0.088868650665413204, 0.088369223537706751, 0.018655072123152854, 0.017913275948177092, 0.011376656188489674, 0.0076897088633626131, 0.0057727900349598986, 0.0051558506419107494]
