How to convert a picture path to mediafile?

I have a picture file path and I am trying to upload this picture to server. When I upload this picture to server I need it's GetStream() value. I will show a sample code, that I have used in another place:

var content = new MultipartFormDataContent();
content.Add(new StreamContent(_mediaFile.GetStream()), "\"file\"", $"\"{_mediaFile.Path}\"");
var response = await httpClient.PostAsync(new Uri("My REST API"), content);

if (response.IsSuccessStatusCode)
{
   //Success
}

Where _mediaFile is a MediaFile

private MediaFile _mediaFile;

But currently, I have only the picture path. So is there any way to convert the picture path to MediaFile or anyway way to get the GetStream() value of the picture path?