Trying to upload image through API. Working fine with FileUpload control but not working when i am using WebCam image

Hi Experts
I am trying to upload image to Amazon server through their API. They require image stream to upload the image file.
When i am using Fileupload control  , it's working fine. 
I am passing (FileUpload1.PostedFile.InputStream) to API
But when i try to upload image through webcam using some code it also uploads the image successfully but blank.
In this case i am passing "Request.InputStream" to API
If i use the following code to save image to local directory using webcam, it works well and saves the image correctly.
if (Request.InputStream.Length > 0) { using (StreamReader reader = new StreamReader(Request.InputStream)) {
string hexString = Server.UrlEncode(reader.ReadToEnd()); string imageName = DateTime.Now.ToString("dd-MM-yy hh-mm-ss"); string imagePath = string.Format("~/Captur ...