Restrict Image by selecting it's URL - vb.net

Question

I am trying to add Images from websites and I am facing poblem with an issue which is that when I am trying to go to google images and trying to add some Images and when I right click for some images I find "Copy Image URL" and for some I don't find it and I find "Copy link address".Now I want my users to restrict from adding the Images which contain "Copy Image URL"
And I am attaching Images so that you'll understand me in a better way.
How do I do that?
Here is the code for saving the image:
Dim dir_name As String = txtDirectory.Text
If Not dir_name.EndsWith("\") Then dir_name &= "\"
For Each pic As PictureBox In flpPictures.Controls
Dim bm As Bitmap = CType(pic.Image, Bitmap)
Dim filename As String = CStr(pic.Tag)
filename = filename.Substring(filename.LastIndexOf("/") + 1)
Dim ext As String = filename.Substring(filename.LastIndexOf("."))
'Here it gives me an error at(filename.lastindexof(".")
Dim full_name As String = dir_name & filename
Select Case ext
Case ".bmp"
bm.Save(full_name, Imaging.ImageFormat.Bmp)
Case ".gif"
bm.Save(full_name, Imaging.ImageFormat.Gif)
Case ".jpg", "jpeg"
bm.Save(full_name, Imaging.ImageFormat.Jpeg)
Case ".png"
bm.Save(full_name, Imaging.ImageFormat.Png)
Case ".tiff"
bm.Save(full_name, Imaging.ImageFormat.Tiff)
Case Else
MessageBox.Show( _
"Unknown file type " & ext & _
" in file " & filename, _
"Unknown File Type", _
MessageBoxButtons.OK, _
MessageBoxIcon.Error)
End Select
Next pic
Beep()

Answer 1

'WEB CLIENT IS NEEDED TO DO THE DOWNLOAD
Dim MyWebClient As New System.Net.WebClient
'BYTE ARRAY HOLDS THE DATA
Dim ImageInBytes() As Byte = MyWebClient.DownloadData(url)
'CREATE A MEMORY STREAM USING THE BYTES
Dim ImageStream As New IO.MemoryStream(ImageInBytes)
'CREATE A BITMAP FROM THE MEMORY STREAM
PictureBox1.Image = New System.Drawing.Bitmap(ImageStream)

Answer 2

In the top screenshot, you are right-clicking directly on an image.
In the bottom screenshot, you are right-clicking on an empty div with a z-index that puts it above the image.
Here's an example:
<a href="http://example.com">
<img src="myImg.jpg" style="position: absolute;" />
<div style="z-index:1; position:absolute; width:100%; height:100%;"></div>
</a>
When you mouse over the link in Google Images another div is shown on top that contains the saveable image. Have a look with Firebug and see for yourself :)
Note that there is no perfect way to prevent users from saving images from your website. You can disable right click, mask the image with a div, mask the image with a transparent image (so the user can right-click and save the image but they get the wrong one), prevent caching etc but ultimately any tech savvy user can get around this. Still, these approaches will stop casual users so it's better than nothing. If you want to find out more about the methods that I just named, I suggest Googling for "disable save image as" or "disable copy image url".

Answer 3

maybe helpful
Sub Base64Convert(ByVal Base64MSG As String)
'Setup image and get data stream together
Dim img As System.Drawing.Image
Dim MS As System.IO.MemoryStream = New System.IO.MemoryStream
Dim b64 As String = Base64MSG
Dim b() As Byte
'Converts the base64 encoded msg to image data
b = Convert.FromBase64String(b64)
MS = New System.IO.MemoryStream(b)
'creates image
img = System.Drawing.Image.FromStream(MS)
'writes image for displaying
img.Save(Request.ServerVariables("APPL_PHYSICAL_PATH") & "LabelInfo.tiff", System.Drawing.Imaging.ImageFormat.Tiff)
'cleaning up house
img.Dispose()
MS.Close()
End Sub