Windows Phone 8 photo/image resizing

Problem:

I am trying to wrap up my first phone application which submits text and photos to an email server.
I wanted to control file size since the user can send anything on their phone.  I had been using the BitmapImage captured directly from the e.ChosenPhoto Task.  There are a number of great tutorials on basic photo capturing.  What they overlook is the the whole resizing issue.   The object for that is WriteableBitmap but you can't just cast the BitmapImage to WriteableBitmap.

The BitmapImage is pretty much immutable once you create it.  That is there is no implicit cast to an object like WriteableBitMap.  Most solutions involve reading the content of the BitmapImage as a stream or array into an image and then casting to to WriteableBitmap.


Solution 1:

Mike Ormond's post was very helpful.  He used a memory stream and saved the resulting byte array to the MediaLibrary.

void task_Completed(object sender, PhotoResult e)
{
  if (e.Error == null)
  {
    BitmapImage bi = new BitmapImage();
    bi.SetSource(e.ChosenPhoto);
    Image image1 = new Image()
    {
      Width = 800,
      Height = 600,
      Visibility = System.Windows.Visibility.Collapsed,
      Source = bi
    };
    ScaleTransform st = new ScaleTransform()
    {
      ScaleX = 0.1,
      ScaleY = 0.1
    };
    WriteableBitmap wb = new WriteableBitmap(image1, st);
    ThreadPool.QueueUserWorkItem(callback =>
    {
      MemoryStream ms = new MemoryStream();
      wb.SaveJpeg(ms, 80, 60, 0, 80);
      using (MediaLibrary lib = new MediaLibrary())
        lib.SavePicture("Test", ms.ToArray());
    });
  }
}

Solution 2:
Take the resulting source photo directly to a WriteableBitmap.


WritableBitmap bitmap = new WritableBitmap(); //Use appropriate constructor
bitmap.SetSource(e.ChosenPhoto);
or

ScaleTransform st = new ScaleTransform()
{
ScaleX = 0.1,
ScaleY = 0.1
};
WriteableBitmap wb = new WriteableBitmap(e.ChosenPhoto, st);

Source:
http://msdn.microsoft.com/en-us/library/dd638675(v=vs.95).aspx
http://stackoverflow.com/questions/8252001/wp7-5e-chosenphoto-issue

 Solution 3:

public void DecodePhoto(byte[] byteVal)
        {
            if (byteVal == null) return ;

            try
            {
                MemoryStream strmImg = new MemoryStream(byteVal);
                BitmapImage myBitmapImage = new BitmapImage();
                myBitmapImage.BeginInit();
                myBitmapImage.StreamSource = strmImg;
                myBitmapImage.DecodePixelWidth = 200;
                myBitmapImage.EndInit();
                MugShot.Source = myBitmapImage;
            }
            catch (Exception ex)
            {
                string message = ex.Message;
            }
        }
Source:
http://stackoverflow.com/questions/8897210/byte-to-bitmapimage
http://stackoverflow.com/questions/14718855/how-to-create-writeablebitmap-from-bitmapimage

Writable bit map SDK

https://www.blogger.com/blogger.g?blogID=8256225704949716108#editor/target=post;postID=5955005466364600781

http://stackoverflow.com/questions/5774038/resizing-resulting-camera-stream