ios - 快速图像处理

Question

我是 Swift 的新手，我正在尝试创建一个在构造函数中采用过滤器公式和强度的类/结构过滤器。此类有一个方法，可以在其参数中将具有给定强度的给定公式应用于图像，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)

最后一行有错误

Cannot convert value of type 'UImage' to expected argument type 'imageFilter'

这是 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

我很确定你的问题是你在尝试调用它的成员方法时没有创建你的类的实例。

用这段代码替换最后一行:

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