MemoryStream and BitmapSource

Question

I have a MemoryStream of 10K which was created from a bitmap of 2MB and compressed using JPEG. Since MemoryStream can’t directly be placed in System.Windows.Controls.Image for the GUI, I am using the following intermediate code to convert this back to BitmapImage and eventually System.Windows.Controls.Image.

            System.Windows.Controls.Image image = new System.Windows.Controls.Image();
            BitmapImage imageSource = new BitmapImage();
            s.SlideInformation.Thumbnail.Seek(0, SeekOrigin.Begin);
            imageSource.BeginInit();
            imageSource.CacheOption = BitmapCacheOption.OnDemand; 
            imageSource.CreateOptions = BitmapCreateOptions.DelayCreation;
            imageSource.StreamSource = s.SlideInformation.Thumbnail;
            imageSource.EndInit();
            imageSource.Freeze();
            image.Source = imageSource;
            ret = image.Source;

My question is, when I store this in BitmapImage, the memory allocation is taking around 2MB. Is this expected? Is there any way to reduce the memory?

I have around 300 thumbnails and this converstion takes around 600MB, which is very high.

Appreciate your help!

Answer 1

Is there any way to reduce the memory?

Yes their is: Don't create your memorystream from the image itself, instead use a thumbnail of it.

Here is a sample code of how to do it:

        private void button1_Click(object sender, EventArgs e)
            {
                Image.GetThumbnailImageAbort myCallback = new Image.GetThumbnailImageAbort(ThumbnailCallback);
                Bitmap myBitmap = new Bitmap(@"C:\Documents and Settings\Sameh\My Documents\My Pictures\Picture\Picture 004.jpg"); //3664 x 2748 = 3.32 MB
                Image myThumbnail = myBitmap.GetThumbnailImage(myBitmap.Width / 100, myBitmap.Height / 100 , myCallback, IntPtr.Zero); 
    //now use your thumbnail as you like
                myThumbnail.Save(@"C:\Documents and Settings\Sameh\My Documents\My Pictures\Picture\Thumbnail 004.jpg");
                //the size of the saved image: 36 x 27 = 2.89 KB
//you can create your memory stream from this thumbnail now
            }

            public bool ThumbnailCallback()
            {
                return false;
            }

And here is more details about the solution.