swift comfress image

mycomfress.swift

/// 图片压缩
    ///
    /// - Parameters:
    ///   - maxFileSize: 压缩后的最大容量，单位 MB
    /// - Returns:
    func mcCompress(maxFileSize: Int) -> Data? {
        
        let maxSize:CGFloat = 4320//4320X2880
        let width = self.size.width
        let height = self.size.height
        var newWidth = width
        var newHeight = height
        var newImage:UIImage? = self
        
        print("Image size is: \(width)" + "x" + "\(height)")
        
        //check if need Resize the image
        if width > maxSize || height > maxSize {
            if width > height {
                newWidth = maxSize
                newHeight = (height * maxSize) / width
            } else {
                newHeight = maxSize
                newWidth = (width * maxSize) / height
            }
            
            // Resize the image
            let newSize = CGSize(width: newWidth, height: newHeight)
            UIGraphicsBeginImageContext(newSize)
            self.draw(in: CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height))
            newImage = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
        }
        
        if let data = UIImageJPEGRepresentation(newImage!, 1) {
                
            let bcf = ByteCountFormatter()
            bcf.allowedUnits = [.useMB]
            bcf.countStyle = .file
            let string = bcf.string(fromByteCount: Int64(data.count))
            print("Data size is: \(string)")
            
            if data.count > (maxFileSize * 1024 * 1024) {
                
                let compression = CGFloat(maxFileSize * 1024 * 1024)/CGFloat(data.count)
                
                if let newData = UIImageJPEGRepresentation(newImage!, compression) {
                    let bcf = ByteCountFormatter()
                    bcf.allowedUnits = [.useMB]
                    bcf.countStyle = .file
                    let string = bcf.string(fromByteCount: Int64(newData.count))
                    print("newData size is: \(string)")
                    return newData
                }
                return nil
            }
            
            return data
        }
        return nil
    }

UIImageComfress.swift

extension UIImage {
    
    /// 图片压缩
    ///
    /// - Parameters:
    ///   - maxFileSize: 压缩后的最大容量，单位 MB
    ///   - compression: 初始压缩值，默认为 1
    /// - Returns:
    func mcCompress(maxFileSize: Int, compression: CGFloat = 1.0) -> Data? {
        
        if let data = UIImageJPEGRepresentation(self, compression) {
            
            let bcf = ByteCountFormatter()
            bcf.allowedUnits = [.useMB]
            bcf.countStyle = .file
            let string = bcf.string(fromByteCount: Int64(data.count))
            print("Data size is: \(string)")
            
            if data.count > (maxFileSize * 1024 * 1024) {
                let newCompression = compression - 0.1
                let compressedData = self.mcCompress(maxFileSize: maxFileSize, compression: newCompression)
                return compressedData
            }
            
            return data
        }
        
        return nil
    }
  
  
  func compress(image: UIImage, maxFileSize: Int, compression: CGFloat = 1.0, maxCompression: CGFloat = 0.4) -> Data? {

        if let data = UIImageJPEGRepresentation(image, compression) {

            let bcf = ByteCountFormatter()
            bcf.allowedUnits = [.useMB] // optional: restricts the units to MB only
            bcf.countStyle = .file
            let string = bcf.string(fromByteCount: Int64(data.count))
            print("Data size is: \(string)")

            if data.count > (maxFileSize * 1024 * 1024) && (compression > maxCompression) {
                let newCompression = compression - 0.1
                let compressedData = self.compress(image: image, maxFileSize: maxFileSize, compression: newCompression, maxCompression: maxCompression)
                return compressedData
            }

            return data
        }

        return nil
    }
}