Swift图像处理

Question

我是新手Swift,我正在尝试创建一个类/结构过滤器,它在构造函数中采用过滤器公式和强度.该类有一种方法,可以在给定参数的图像中应用给定强度的给定公式,然后返回修改后的图像.

我们有一个叫做类的RGBAImage.swift方法,它有将方法转换UIImage成RGBAImage,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)

最后一行说错了

无法将'UImage'类型的值转换为预期的参数类型'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

我非常确定您的问题是您在尝试调用其成员方法时没有创建类的实例。

将最后一行替换为以下代码：

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