swift 判断比较两张图片是否相同 - 感知哈希算法

概述首先是对图片进行处理: //1.缩小图片尺寸 func scaleToSize(img: UIImage, size: CGSize) -> UIImage { UIGraphicsBeginImageContext(size) img.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.h

首先是对图片进行处理:

//1.缩小图片尺寸    func scaletoSize(img: UIImage,size: CGSize) -> UIImage {        UIGraphicsBeginImageContext(size)        img.draw(in: CGRect(x: 0,y: 0,wIDth: size.wIDth,height: size.height))        let scaledImage = UIGraphicsGetimageFromCurrentimageContext()        UIGraphicsEndImageContext()        return scaledImage!    }

//2.简化色彩 将图片转换成灰度图片    func getGrayImage(sourceImage: UIImage) -> UIImage {        let imageRef: CGImage = sourceImage.cgImage!        let wIDth: Int = imageRef.wIDth        let height: Int = imageRef.height        let colorSpace = CGcolorSpaceCreateDeviceGray()        let bitmAPInfo = CGBitmAPInfo(rawValue: CGImageAlphaInfo.none.rawValue)        let context: CGContext = CGContext(data: nil,wIDth: wIDth,height: height,bitsPerComponent: 8,bytesPerRow: 0,space: colorSpace,bitmAPInfo: bitmAPInfo.rawValue)!        let rect: CGRect = CGRect.init(x: 0,height: height)        context.draw(imageRef,in: rect)        let outPutimage: CGImage = context.makeImage()!        let newImage: UIImage = UIImage.init(cgImage: outPutimage)        return newImage    }

//3. 计算平均值,比较像素的灰度    func pHashValueWithImage(image: UIImage) -> Nsstring {        let pHashString = NSMutableString()        let imageRef = image.cgImage!        let wIDth = imageRef.wIDth        let height = imageRef.height        let pixelData = imageRef.dataProvIDer!.data        let data: UnsafePointer<UInt8> = CFDataGetBytePtr(pixelData)        var sum: Int = 0        for i in 0..<wIDth * height {            if data[i] != 0 { sum = sum + Int(data[i]) }        }        let avr = sum / (wIDth * height)        for i in 0..<wIDth * height {            if Int(data[i]) >= avr { pHashString.append("1") } else { pHashString.append("0") }        }        return pHashString    }

//4.计算哈希值 如果不相同的数据位不超过5，就说明两张图片很相似；如果大于10，就说明这是两张不同的图片。    func getDifferentValueCountWithString(str1: Nsstring,str2: Nsstring) -> NSInteger {        var diff: NSInteger = 0        let s1 = str1.utf8String!        let s2 = str2.utf8String!        for i in 0..<str1.length {            if s1[i] != s2[i] {                diff += 1            }        }        return diff    }

写个共用方法来比较两个图片是否相同

/// 比较两个图片是否相同,这里比较尺寸为20*20    ///    /// - Parameters:    /// - imageOne: 图片1    /// - imageTwo: 图片2    /// - Returns: 是否相同的布尔值    func isEqualimage(imageOne: UIImage,imageTwo: UIImage) -> Bool {        var equalResult = false        let mImageOne = self.getGrayImage(sourceImage: self.scaletoSize(img: imageOne,size: CGSize(wIDth: 20,height: 20)))        let mImageTwo = self.getGrayImage(sourceImage: self.scaletoSize(img: imageTwo,height: 20)))        let diff = self.getDifferentValueCountWithString(str1: self.pHashValueWithImage(image: mImageOne),str2: self.pHashValueWithImage(image: mImageTwo))        print(diff)        if diff > 10 {            equalResult = false        } else {            equalResult = true        }        return equalResult    }

通过调用上面的共用方法,传入两个待比较的UIImage对象,得到返回的Bool,根据该布尔值进行相应的 *** 作

总结

以上是内存溢出为你收集整理的swift 判断/比较两张图片是否相同 - 感知哈希算法全部内容，希望文章能够帮你解决swift 判断/比较两张图片是否相同 - 感知哈希算法所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。