UIImage Pixel

UIImage+Pixel.swift

extension UIImage {
    
    func maxArea() -> CGRect{
        let provider = self.cgImage!.dataProvider
        let providerData = provider!.data
        let data = CFDataGetBytePtr(providerData)
        
        var minX = 0
        var minY = 0
        var maxX = 0
        var maxY = 0
        
        for row in 0..<Int(self.size.height) {
            for col in 0..<Int(self.size.width) {
    
                let numberOfComponents = 4
                let pixelData = ((Int(size.width) * row) + col) * numberOfComponents
                
                let r = CGFloat(data![pixelData]) / 255.0
                let g = CGFloat(data![pixelData + 1]) / 255.0
                let b = CGFloat(data![pixelData + 2]) / 255.0
                let a = CGFloat(data![pixelData + 3]) / 255.0
                if r != 0 || g != 0 || b != 0 || a != 0 {
                    if r == 1 && g == 1 && b == 1 && a == 1 {
                        continue
                    } else {
                        if row >= maxY {
                            maxY = row
                        }
                        if row <= minY {
                            minY = row
                        }
                        if col >= maxX {
                            maxX = col
                        }
                        if col <= minX {
                            minX = col
                        }
                    }
                }
            }
        }
       return CGRect(x: minX, y: minY, width: maxX - minX, height: maxY - minY)
    }
    
    func pixelData() -> [Pixel] {
        let provider = self.cgImage!.dataProvider
        let providerData = provider!.data
        let data = CFDataGetBytePtr(providerData)
        
        var r, g, b, a: UInt8
        var pixels: [Pixel] = []
        
        for row in 0..<Int(self.size.height) {
            for col in 0..<Int(self.size.width) {
//                r = data.memory
//                data = data?.advancedBy(1)
//                g = data.memory
//                data = data.advancedBy(1)
//                b = data.memory
//                data = data.advancedBy(1)
//                a = data.memory
//                data = data.advancedBy(1)
//                pixels.append(Pixel(r: r, g: g, b: b, a: a, row: row, col: col))
            
                let numberOfComponents = 4
                let pixelData = ((Int(size.width) * col) + row) * numberOfComponents
                
                let r = CGFloat(data![pixelData]) / 255.0
                let g = CGFloat(data![pixelData + 1]) / 255.0
                let b = CGFloat(data![pixelData + 2]) / 255.0
                let a = CGFloat(data![pixelData + 3]) / 255.0
                pixels.append(Pixel(r: UInt8(r), g:  UInt8(g), b:  UInt8(b), a:  UInt8(a), row: row, col: col))
            }
        }
        
        return pixels
    }
}

struct Pixel {
    var r: Float
    var g: Float
    var b: Float
    var a: Float
    var row: Int
    var col: Int
    
    init(r: UInt8, g: UInt8, b: UInt8, a: UInt8, row: Int, col: Int) {
        self.r = Float(r)
        self.g = Float(g)
        self.b = Float(b)
        self.a = Float(a)
        self.row = row
        self.col = col
    }
    
    var color: UIColor {
        return UIColor(red: CGFloat(r/255.0), green: CGFloat(g/255.0), blue: CGFloat(b/255.0), alpha: CGFloat(a/255.0))
    }
    
    var description: String {
        return "RGBA(\(r), \(g), \(b), \(a))"
    }
}