发送到多部分时将图像大小压缩到 1.5 MB ios swift

Question

我正在上传大小小于 1.5 MB 的图像（在 imagePickerController 中选择），然后将其保存到 Userdefault，但是当我尝试获取它时，它的大小会增加。因此，在将其上传到 Multipart 时，我再次尝试按如下方式对其进行压缩。它给了我“2122 字节”。没关系，因为它小于 1.5 MB。但主要问题是我无法上传它。

let compressData = UIImage(data:UserDefaultValues.imagep1! as Data)!.jpegData(compressionQuality: 0)

print("length:", UIImage(data:compressData!)!.jpegData(compressionQuality: 0)!)//2122 bytes

let compressData2 = UIImage(data:UserDefaultValues.imagep3! as Data)?.jpegData(compressionQuality: 0) 

print("length2:", UIImage(data:compressData2!)!.jpegData(compressionQuality: 0)!)//2122 bytes


multipartFormData: { multipartFormData in

                    multipartFormData.append(compressData!, withName: "image", fileName: "", mimeType: "image/png")
                    multipartFormData.append("\(storyid)".data(using: .utf8)! , withName: "story_id")
                    multipartFormData.append(compressData2!, withName: "series_image", fileName: "", mimeType: "image/png")
                    multipartFormData.append("\(seriesid)".data(using: .utf8)! , withName: "series_id")

},

Answer 1

Image Compression extension 可能会帮助您保持可发送图像大小一致。

Uploading multipartFormData

 Alamofire.upload(multipartFormData: { multipartFromData in
                    if !fileData.isEmpty {
                        multipartFromData.append(fileData, withName: "file", fileName: "\(UUID().uuidString).png", mimeType: "image/png")
                    }

                }, to:URL , method: .post, headers: headers, encodingCompletion: { result in
                    print(result)

                    switch result {
                    case .success(let upload, _, _):
                        upload.validate(statusCode: 200 ..< 300).responseString(completionHandler: { _ in
                         print("Upload success")
                        })
                    case .failure(let error):
                        print(error.localizedDescription)
                    }
                })

Answer 2

这是使用示例代码在服务器上上传图片的一些步骤

第 1 步：使用 URLSession 上传图片

    var croppedImage = UIImage()

    func imageUploadRequest(){
    let getUserData :UserDefaults = UserDefaults.standard
    let User_Id = getUserData.value(forKey: "userid")
    print("userid :\(String(describing: User_Id))!)")
    let myUrl = NSURL(string: "Enter API String Here");
    let request = NSMutableURLRequest(url:myUrl! as URL);
    request.httpMethod = "POST";
    let param = [
        "user_id"  : "\(User_Id!)",

    ]
    let boundary = generateBoundaryString()
    request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
    //Pass image in compressImage function
    let compressedImage = self.compressImage(image: croppedImage)
    //Convert It NSData To UIImage and also pass scale value for compression
    convertedImage = UIImage(data:compressedImage as Data,scale:1.0)!
    print("print Lates compress image size : \(convertedImage.size)")
    let imageData = UIImageJPEGRepresentation(convertedImage, 1)
    if(imageData==nil)  { return; }
    request.httpBody = createBodyWithParameters(parameters: param, filePathKey: "fileToUpload", imageDataKey: imageData! as NSData, boundary: boundary) as Data
    //Pass This converted Image To Server
    let task = URLSession.shared.dataTask(with: request as URLRequest) {
        data, response, error in
        if error != nil {
            print("error=\(String(describing: error))")
            return
        }
        // You can print out response object
        print("******* response = \(String(describing: response))")
        // Print out reponse body
        let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue)
        print("****** response data = \(responseString!)")
        //Show Alert after successfull uploaded
        DispatchQueue.main.async {
            //resolved view is not hiararchy issue.
            let createProfileVC = UIStoryboard(name: "Main", bundle:nil).instantiateViewController(withIdentifier: "CreateProfileViewController") as! CreateProfileViewController
            let appDelegate = (UIApplication.shared.delegate as! AppDelegate)
            appDelegate.window?.rootViewController = createProfileVC
        }
        do {
            let json = try JSONSerialization.jsonObject(with: data!, options: []) as? NSDictionary
            print(json)
            self.imageView.image = nil;
        }catch
        {
            print(error)
        }
      }
    task.resume()
  }

func createBodyWithParameters(parameters: [String: String]?, filePathKey: String?, imageDataKey: NSData, boundary: String) -> NSData {
    let body = NSMutableData();
    if parameters != nil {
        for (key, value) in parameters! {
            body.appendString(string: "--\(boundary)\r\n")
            body.appendString(string: "Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n")
            body.appendString(string: "\(value)\r\n")
        }
    }
    let filename = "profileImage"
    let mimetype = "image/jpg"
    body.appendString(string: "--\(boundary)\r\n")
    body.appendString(string: "Content-Disposition: form-data; name=\"\(filePathKey!)\"; filename=\"\(filename)\"\r\n")
    body.appendString(string: "Content-Type: \(mimetype)\r\n\r\n")
    body.append(imageDataKey as Data)
    body.appendString(string: "\r\n")

    body.appendString(string: "--\(boundary)--\r\n")

    return body
}

func generateBoundaryString() -> String {
    return "Boundary-\(NSUUID().uuidString)"
}

第二步：图片压缩

 //Need to convert NSData to UIImage
func compressImage(image:UIImage) -> NSData {
    // Reducing file size to a 10th

    var actualHeight : CGFloat = image.size.height
    var actualWidth : CGFloat = image.size.width
    var maxHeight : CGFloat = 1136.0
    var maxWidth : CGFloat = 640.0
    var imgRatio : CGFloat = actualWidth/actualHeight
    var maxRatio : CGFloat = maxWidth/maxHeight
    var compressionQuality : CGFloat = 0.5

    if (actualHeight > maxHeight || actualWidth > maxWidth){
        if(imgRatio < maxRatio){
            //adjust width according to maxHeight
            imgRatio = maxHeight / actualHeight;
            actualWidth = imgRatio * actualWidth;
            actualHeight = maxHeight;
        }
        else if(imgRatio > maxRatio){
            //adjust height according to maxWidth
            imgRatio = maxWidth / actualWidth;
            actualHeight = imgRatio * actualHeight;
            actualWidth = maxWidth;
        }
        else{
            actualHeight = maxHeight;
            actualWidth = maxWidth;
            compressionQuality = 1;
        }
    }


    var rect = CGRect(x: 0.0, y:0.0 , width:actualWidth , height: actualHeight)

    UIGraphicsBeginImageContext(rect.size);
    image.draw(in: rect)
    var img = UIGraphicsGetImageFromCurrentImageContext();
    let imageData = UIImageJPEGRepresentation(img!, compressionQuality);
    UIGraphicsEndImageContext();

    return imageData as! NSData;
}

}

扩展 NSMutableData {

func appendString(string: String) {
    let data = string.data(using: String.Encoding.utf8, allowLossyConversion: true)
    append(data!)
}

}

Answer 3

答案：

func sendStorySeriesImage(seriesid: Int, storyid: Int){
    let sv = UIViewController.displaySpinner(onView: view)
    guard let compressData2 = (UIImage(data:UserDefaultValues.imagep1! as Data)!).jpegData(compressionQuality: 0.5) else {
        return
    }
    guard let compressData = (UIImage(data:UserDefaultValues.imagep1! as Data)!).jpegData(compressionQuality: 0.5) else {
        return
    }

let url = URL(string: Constants.wevlrBaseUrl + Constants.privateLink + Constants.createstoryseriesImage)!

Alamofire.upload(
    multipartFormData: { multipartFormData in

    multipartFormData.append("\(storyid)".data(using: .utf8)! , withName: "story_id")
    multipartFormData.append("\(seriesid)".data(using: .utf8)! , withName: "series_id")
    multipartFormData.append(compressData, withName: "image", fileName: "\(UUID().uuidString).jpg", mimeType: "image/jpg")
    multipartFormData.append(compressData2, withName: "series_image", fileName: "\(UUID().uuidString).jpg", mimeType: "image/jpg")

},
        to: url,
        method : .post,
        headers : Constants.headers,
        encodingCompletion: { encodingResult in
        switch encodingResult {
        case .success(let upload, _, _):

        upload.responseJSON { response in

            debugPrint(response)
            switch response.result {
            case .success(let data):
                UIViewController.removeSpinner(spinner: sv)
                let dict = response.result.value as! NSDictionary
                let statusCode = response.response?.statusCode

                if(statusCode == 201) {
                            UIViewController.removeSpinner(spinner: sv)
                            self.alert(title: "Success!", message: (dict["msg"] as? String)!)



               }else{
                            UIViewController.removeSpinner(spinner: sv)
                            self.alert(title: "Alert!", message: (dict["msg"] as? String)!)
                           }
            break
            case .failure(_):
             self.alert(title: "Alert!", message: "Something went wrong. Please try again.")
            break
            }

        }
        case .failure(_):
         self.alert(title: "Alert!", message: "Something went wrong. Please try again.")
        break
        }
    }
        )

}

Answer 4

您可以在多部分发送图像之前压缩图像。使用以下功能，您将获得压缩图像数据和完成时质量损失最小的图像。

extension UIImage {
func compressImageBelow(kb: Double, completion:(UIImage?, Data?) -> Void) {
    if let imageData = self.jpegData(compressionQuality: 0.5)
    {
      var resizingImage = self
      var imageSizeKB = Double(imageData.count) / 1000.0
      var imgFinalData: Data = imageData
      while imageSizeKB > kb {
            if let resizedImage = resizingImage.resized(withPercentage: 0.9),
                let imageData = resizedImage.jpegData(compressionQuality: 0.5) {
                resizingImage = resizedImage
                imageSizeKB = Double(imageData.count) / 1000.0 // ! Or devide for 1024 if you need KB but not kB
                imgFinalData = imageData
                print("There were \(imageData.count) bytes")
                let bcf = ByteCountFormatter()
                bcf.allowedUnits = [.useMB] // optional: restricts the units to MB only
                bcf.countStyle = .file
                let string = bcf.string(fromByteCount: Int64(imageData.count))
                print("formatted result: \(string)")
            }
        }
        completion(self, imgFinalData);
    }
    completion(nil, nil);
  }
}

用法：

image.compressImageBelow(kb: 1500.0, completion: { (compressedImage, imageData) in
  guard let imgData = imageData else {
    return
  }
  //Use compressedImage here or
  //Send img data in multiparts
}

Answer 5

这个解决方案对我有用

func resize(_ expectedSizeInMb:Int) -> Data? {
        guard let fileSize = self.jpegData(compressionQuality: 1) else {return nil}
        let Size = CGFloat(Double(fileSize.count)/1024/1024)
        // I am checking 5 MB size here you check as you want
        if Size > CGFloat(expectedSizeInMb) {
            let sizeInBytes: CGFloat = CGFloat(expectedSizeInMb * 1024 * 1024)
            let leastExpectedSize: CGFloat = (CGFloat(expectedSizeInMb) - 1) * 1024 * 1024
            var imgData:Data?
            var start: CGFloat = 0
            var end: CGFloat = 1
            var mid: CGFloat = (end+start)/2
            while true {
                imgData = self.jpegData(compressionQuality: CGFloat(mid))
                print("current image size \(CGFloat(imgData!.count)/(1024*1024))")
                print("1st \(start) 2nd \(mid) 3rd \(end)")
                if CGFloat(imgData?.count ?? 0) > sizeInBytes {
                    end = mid
                    mid = (start+end)/2
                } else if CGFloat(imgData?.count ?? 0) < sizeInBytes && CGFloat(imgData?.count ?? 0) < leastExpectedSize {
                    start = mid
                    mid = (start+end)/2
                } else {
                    print("returning")
                    return imgData
                }
            }
        }
        return fileSize
    }

发送到多部分时将图像大小压缩到 1.5 MB ios swift

Compress image size to 1.5 MB while sending to multipart ios swift

multipartform-data

uiimage

ios

swift