Swift图像处理

Question

我是Swift的新手，我试图创建一个类/结构过滤器，它在构造函数中使用过滤器公式和强度。这个类有一个方法可以将给定强度的给定公式应用于参数中的图像，然后返回修改后的图像。

我们有一个名为RGBAImage.swift的类，它具有将UIImage转换为RGBAImage的方法，反之亦然。

这是我创建的类：

import UIKit 


let image = UIImage(named: "sample")! 






class imageFilter{ 


    func increaseContrast(image: UIImage) -> UIImage{ 
     let rgbaImage = RGBAImage(image: image)! 
     var totalRed = 0 
     var totalGreen = 0 
     var totalBlue = 0 
     let pixelCount = rgbaImage.width * rgbaImage.height 

     for y in 0..<rgbaImage.height { 
      for x in 0..<rgbaImage.width { 
       let index = y * rgbaImage.width + x 
       let pixel = rgbaImage.pixels[index] 
       totalRed += Int(pixel.red) 
       totalGreen += Int(pixel.green) 
       totalBlue += Int(pixel.blue) 
      } 
     } 


     let avgRed = totalRed/pixelCount 
     let avgGreen = totalGreen/pixelCount 
     let avgBlue = totalBlue/pixelCount 


     for y in 0..<rgbaImage.height { 
      for x in 0..<rgbaImage.width { 
       let index = y * rgbaImage.width + x 
       var pixel = rgbaImage.pixels[index] 
       let redDelta = Int(pixel.red) - avgRed 
       let greenDelta = Int(pixel.green) - avgGreen 
       let blueDelta = Int(pixel.blue) - avgBlue 
       pixel.red = UInt8(max(min(255, avgRed + 2 * redDelta), 0)) 
       pixel.blue = UInt8(max(min(255, avgBlue + 2 * blueDelta), 0)) 
       pixel.green = UInt8(max(min(255, avgGreen + 2 * greenDelta), 0)) 
       rgbaImage.pixels[index] = pixel 


       } 
      } 
     let finished = rgbaImage.toUIImage()! 
     return (finished) 
     } 


} 


let test = imageFilter.increaseContrast(image) 

有一个错误在最后一行说

无法将类型的价值“的uImage”预期参数类型 “ImageFilter的”

这里是RGBA类：

import UIKit 

public struct Pixel { 
    public var value: UInt32 

public var red: UInt8 { 
    get { 
     return UInt8(value & 0xFF) 
    } 
    set { 
     value = UInt32(newValue) | (value & 0xFFFFFF00) 
    } 
} 

public var green: UInt8 { 
    get { 
     return UInt8((value >> 8) & 0xFF) 
    } 
    set { 
     value = (UInt32(newValue) << 8) | (value & 0xFFFF00FF) 
    } 
} 

public var blue: UInt8 { 
    get { 
     return UInt8((value >> 16) & 0xFF) 
    } 
    set { 
     value = (UInt32(newValue) << 16) | (value & 0xFF00FFFF) 
    } 
} 

public var alpha: UInt8 { 
    get { 
     return UInt8((value >> 24) & 0xFF) 
    } 
    set { 
     value = (UInt32(newValue) << 24) | (value & 0x00FFFFFF) 
    } 
    } 
} 




public struct RGBAImage { 
public var pixels: UnsafeMutableBufferPointer<Pixel> 

public var width: Int 
public var height: Int 

public init?(image: UIImage) { 
    guard let cgImage = image.CGImage else { return nil } 

    // Redraw image for correct pixel format 
    let colorSpace = CGColorSpaceCreateDeviceRGB() 

    var bitmapInfo: UInt32 = CGBitmapInfo.ByteOrder32Big.rawValue 
    bitmapInfo |= CGImageAlphaInfo.PremultipliedLast.rawValue & CGBitmapInfo.AlphaInfoMask.rawValue 

    width = Int(image.size.width) 
    height = Int(image.size.height) 
    let bytesPerRow = width * 4 

    let imageData = UnsafeMutablePointer<Pixel>.alloc(width * height) 

    guard let imageContext = CGBitmapContextCreate(imageData, width, height, 8, bytesPerRow, colorSpace, bitmapInfo) else { return nil } 
    CGContextDrawImage(imageContext, CGRect(origin: CGPointZero, size: image.size), cgImage) 

    pixels = UnsafeMutableBufferPointer<Pixel>(start: imageData, count: width * height) 
} 

public func toUIImage() -> UIImage? { 
    let colorSpace = CGColorSpaceCreateDeviceRGB() 
    var bitmapInfo: UInt32 = CGBitmapInfo.ByteOrder32Big.rawValue 
    bitmapInfo |= CGImageAlphaInfo.PremultipliedLast.rawValue & CGBitmapInfo.AlphaInfoMask.rawValue 

    let bytesPerRow = width * 4 

    let imageContext = CGBitmapContextCreateWithData(pixels.baseAddress, width, height, 8, bytesPerRow, colorSpace, bitmapInfo, nil, nil) 

    guard let cgImage = CGBitmapContextCreateImage(imageContext) else {return nil} 
    let image = UIImage(CGImage: cgImage) 

    return image 
} 
} 

Answer 1

我非常肯定你的问题是你在尝试调用它的成员方法时没有创建过类的实例。

与此代码替换最后一行：

let test = imageFilter() 
let processedImg = test.increaseContrast(image)