This script was supplied by an astute customer,
Magnus Lindbergh of CreateIT web agency in Sweden. Thanks Magnus!
It assumes that the image has been uploaded to a database, but could
easily be adapted when the image is uploaded to a file. For use with
a file, use ASP's Scripting.FileSystemObject to read the first few
bytes of the image.
<%
SQL = "SELECT BLOB "
SQL = SQL & "FROM objectIMAGE WHERE (((objectIMAGE.imageID)=" &
Request.QueryString("imageID") & "));"
Set Connection = Server.CreateObject("ADODB.Connection")
Set RS = Server.CreateObject("ADODB.RecordSet")
RS.Open SQL, "DSN=DN", 3, 3
Dim BitSet
ReDim BitSet (10)
For I = 0 to 10
BitSet(I) = RS.Fields("BLOB").GetChunk(1)
Next
' Calculate GIF width & height using bit 6-9
width = (256 * AscB(BitSet(7))) + AscB(BitSet(6))
height = (256 * AscB(BitSet(9))) + AscB(BitSet(8))
' Max width / height
MaxWidth = 300
MaxHeight = 200
' Resize the image
iWidth = width
iHeight = height
If iWidth > MaxWidth Then
iHeight = iHeight * maxWidth / iWidth
iWidth = maxWidth
End If
If iHeight > MaxHeight Then
iWidth = iWidth * maxHeight / iHeight
iHeight = maxHeight
End If
' Store Values in Session variables
Session("sWidth") = iWidth
Session("sHeight") = iHeight
%>
This script must be executed before doing the binarywrite.
This script will be called from the .asp page after executing the above script.
Using a HTML TAG like:
<img src="resize_gif.asp?imageID=<%=request.querystring("objectID")%>"
width="<%=Cint(Session("sWidth"))%>"
height="<%=Cint(Session("sHeight"))%>">
Note the use of Session("sWidth") & Session("sHeight"),
which are calculated in the first script.
resize_gif.asp
<%
MaxSize = 700000
Response.Expires = 0
Response.Buffer = TRUE
Response.Clear
Response.ContentType="image/gif"
Set Connection = Server.CreateObject("ADODB.Connection")
Connection.Open "DSN=DN"
SQLB = "SELECT BLOB FROM objectIMAGE WHERE imageID ="
SQLB = SQLB & Request.QueryString("imageID")
Set rsBlob = Connection.Execute(SQLB)
Response.BinaryWrite rsBlob("BLOB").getChunk(MaxSize)
Response.End
%>
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