c# - Get captcha image from WebBrowser with alpha, without downloading it -

I tried to use this type of clipboard method:

  foreach ( IHTMLImgElement img in doc .images) {if (img.src.Contains (name)) {var imgRange = (IHTMLControlRange) body.createControlRange (); ImgRange.add (IMHTMLControlElement) IMG); ImgRange.execCommand ("copy", false, zero); Return (bitmap) clipboard. GetImage (); }}   
 But it gives me an image without alpha. 
 alpha is unreadable without captcha. 
  
 So, is there any other way to get the image from the browser?   
 
 
 If you have any cookie set, delete it so that you can get the actual captcha. / P>