display image from database(using handler)

.aspx

<asp:Image ID="Image1" runat="server"  ImageUrl="Handler.ashx" />

Handler.ashx

Public Class Handler : Implements IHttpHandler, IRequiresSessionState

Public Sub ProcessRequest(ByVal context As HttpContext) Implements                IHttpHandler.ProcessRequest

        Dim imageData() As Byte       
        Dim query As String = "your query"

        imageData = "Execute your query"
        context.Response.ContentType = "image/jpg"
        context.Response.BinaryWrite(imageData)

    End Sub
   
End Class

Note:

you can use a query string to pass information

                      "Handler.ashx?id="xxx"

Request by

                      context.Request.QueryString("id")