ASP.NET Discussion - thumbnail resize URI format

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thumbnail resize URI format

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Category: General Discussion
Forum Name: ASP.NET Discussion
Forum Description: Discussion and chat on ASP.NET related topics.
URL: https://forums.webwiz.net/forum_posts.asp?TID=11286
Printed Date: 28 March 2026 at 4:07am
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Topic: thumbnail resize URI format

Posted By: Badaboem
Subject: thumbnail resize URI format
Date Posted: 25 July 2004 at 3:19pm

Is it impossible to use URI formats with asp.net image resizing?

I'm trying to adjust a script that is able to resize images on my local server, but once adjusted to use http:// or www. etc. it gives the following error:
URI formats not supported

What is causing this issue, and is there a way to work around this issue?

Here's the script. I deleted the parts in red for it to accept http or www links (or so i hoped)



<%@ Import Namespace=System.Drawing %>

<%@ Import Namespace=System %>

<%@ Import Namespace=System.Web %>



<html>

<script language="VB" runat="server">



Sub Page_Load(Sender As Object, E As EventArgs)

    

' Dim all Variables

    Dim OrginalImg, Thumb As System.Drawing.Image

    Dim Rootpath, FileName As String

    Dim imgHeight, imgWidth, maxWidth, MaxHeight As Integer

    Dim inp As New IntPtr()

 

' Get width using QueryString.

    If Request.QueryString("width") = Nothing Then

        maxWidth = orginalimg.Width

    ElseIf Request.QueryString("width") = 0 Then

        maxWidth = 180    

           
           
    

    Else

         maxWidth = Request.QueryString("width")

 End If



 

' Get height using QueryString.

    If Request.QueryString("height") = Nothing Then

        MaxHeight = orginalimg.Height

    ElseIf Request.QueryString("height") = 0 Then

        MaxHeight = 20

    Else

        MaxHeight = Request.QueryString("height")

    End If

 

' Get Root Application Folder

    rootpath = Server.MapPath("/")



' Get filename

    FileName = rootpath & Request.QueryString("FileName")



' Attempt to populate the original image object    

    Try

        orginalimg = orginalimg.FromFile(FileName)



' Get the current Height and width of the image

        imgHeight = orginalimg.Height

        imgWidth = orginalimg.Width



' Check to see if the image even needs scaled

        If imgWidth > maxWidth Or imgHeight > MaxHeight Then



'Determine what dimension is off by more

            Dim deltaWidth As Integer = 1

            Dim deltaHeight As Integer = 2

            Dim scaleFactor As Double

 

    

            If deltaHeight > deltaWidth Then



' Use the Height to set the scale factor

                scaleFactor = MaxHeight / imgHeight

            Else



' Use the Width to set the scale factor

                scaleFactor = maxWidth / imgWidth

            End If

 

' Set the new Scaled the image Size 

            imgWidth *= scaleFactor

            imgHeight *= scaleFactor

        End If



' If the population fails get error.gif

    Catch

        orginalimg = orginalimg.FromFile(rootpath & "error.gif")

    End Try



' set the thumbnail width and height by the new correct scale

    thumb = orginalimg.GetThumbnailImage(imgWidth, imgHeight, Nothing, inp)

 

'Sending Response JPEG type to the browser. 

    Response.ContentType = "image/jpeg"

    thumb.Save(Response.OutputStream, Imaging.ImageFormat.Jpeg)

 

 'Disposing the objects.

    orginalimg.Dispose()

    thumb.Dispose() 



  End Sub

</script>

</html>

Thanks for your help.

Replies:

Posted By: dpyers
Date Posted: 25 July 2004 at 3:48pm

URI = URL (URI - Universal Resource Indicator is the proper name for what most people call a URL). Basically, the message indicates a badly formed URL.

Do a response.write on Server.MapParh("/") I don't think it contains what you think it does.

-------------

Lead me not into temptation... I know the short cut, follow me.

Posted By: Badaboem
Date Posted: 25 July 2004 at 3:56pm

i have deleted the red parts as stated before, so the response.write should be done on filename in this case.

Server.MapPAth is not used anymore because i want it to link to external images instead of images on my own server.

"Filename" does return the proper url: http://129.125.101.174/c4dportal2/uploads/telnoiadmin/ downloads/2004-07-05_000346_nprsetup.jpg

Could it be that urls are simply not supported by image resizing in asp.net?

Posted By: Badaboem
Date Posted: 25 July 2004 at 4:06pm

I'm beginning to suspect ''FromFile" doesn't support uri formats.

Posted By: dpyers
Date Posted: 25 July 2004 at 5:39pm

Here's an article on image resizing that may help.
http://aspnet.4guysfromrolla.com/articles/012203-1.aspx - http://aspnet.4guysfromrolla.com/articles/012203-1.aspx

-------------

Lead me not into temptation... I know the short cut, follow me.

Posted By: Badaboem
Date Posted: 27 July 2004 at 4:08pm

Thanks for that link, but it discusses the same old script in a somewhat different form.

I've searched google, several asp.net forums and nothing came up with an answer as to if it's possible to use system draw on remote images.

If anybody knows (an alternative), please do let me know.