private void pdfViewer1_MouseClick(object sender, MouseEventArgs e)
{
	var page = pdfViewer1.Document.Pages.CurrentPage;
	var index = pdfViewer1.Document.Pages.CurrentIndex;

	foreach (var obj in page.PageObjects)
	{
		if (!(obj is PdfImageObject))
			continue;

		var boundingBox = obj.BoundingBox;
		var mousePoint = pdfViewer1.ClientToPage(index, e.Location);
		if (boundingBox.Contains(new Point((int)mousePoint.X, (int)mousePoint.Y)))
		{
			(obj as PdfImageObject).Bitmap.Image.Save(...);
		}
	}
}