errore con resize di un'immagine

[erlupacchiotto]

sto' utilizzando uno script aspx che ridimensiona sul server le immagini prima di caricarle sul client, al fine di ottimizzare i tempi di caricamento della pagina

Il problema che mi si pone e' che funziona SOLO SE
Altezza < Larghezza
anche di un solo pixel

come mai ?
guarda questa pagina
http://www.erlupacchiotto.com/prova/Foto/FotoRedim.html
solo la foto di dx viene caricata, quella al centro invece no

grazie a tutti anticipatamente

-------redim.html----------
PROVA FOTO 90*90
<img src="resize.aspx?src=Foto4.jpg&w=150&h=150">
PROVA FOTO 90*89
<img src="resize.aspx?src=Foto5.jpg&w=150&h=150">

-------resize.aspx----------
<%@ import namespace="System" %>
<%@ import namespace="System.Drawing" %>
<%@ import namespace="System.Drawing.Imaging" %>
<%@ import namespace="System.IO" %>

<script runat="server">

Function NewthumbSize(currentwidth, currentheight)


' Calculate the Size of the New image




dim k,a,b,c,d as Double

k=currentwidth/currentheight

a=currentwidth
b=currentheight
c=Request.QueryString("h")
d=Request.QueryString("w")



'if (k<=1 and currentheight>=c) then
'a=c*k
'b=c
'end if

if (k>1) then

a=d
b=d/k

else

a=c*k
b=c

end if




dim NewSize as New Size(a, b)








return NewSize

End Function


Sub sendFile()

' create New image and bitmap objects. Load the image file and put into a resized bitmap.
dim g as System.Drawing.Image = System.Drawing.Image.FromFile(server.mappath(request("src")))
'dim g as System.Drawing.Image = System.Drawing.Image.FromFile(request("src"))






' initialise the web object
'Dim webC As New System.Net.WebClient()

' set the URL
'Dim strFilename as string

'if Request.QueryString("src")="" then
' strFilename="http://127.0.0.1/chiave.jpg"
'else
' strFilename="http://127.0.0.1/thumbaspx/"&Request.QueryString("src")
'end if

' create a bitmap based on the image from the URL
'Dim g = New System.Drawing.Bitmap(webC.OpenRead(strFilename))










dim thisFormat=g.rawformat

dim thumbSize as New size
thumbSize=NewthumbSize(g.width,g.height)

dim imgOutput as New Bitmap(g, thumbSize.width, thumbSize.height)

' Set the contenttype

'if thisformat.equals(system.drawing.imaging.imageformat.Gif) then
'response.contenttype="image/gif"
'else
response.contenttype="image/jpeg"
'end if



' send the resized image to the viewer
imgOutput.save(response.outputstream, thisformat) ' output to the user

' tidy up
g.dispose()
imgOutput.dispose()

end sub

Sub sendError()

' if no height, width, src then output "error"
dim imgOutput as New bitmap(120, 120, pixelformat.format24bpprgb)
dim g as graphics = graphics.fromimage(imgOutput)
'create a New graphic object from the above bmp
g.clear(color.yellow) ' blank the image
g.drawString("ERRORE!", New font("verdana",14,fontstyle.bold),systembrushes.windowtext,new pointF(2,2))

' Set the contenttype
response.contenttype="image/jpeg"

' send the resized image to the viewer
imgOutput.save(response.outputstream, imageformat.jpeg) ' output to the user

' tidy up
g.dispose()
imgOutput.dispose()


end sub


</script>



<%


' make sure Nothing has gone to the client
response.clear


if request("src")="" then

call sendError()

else

if file.exists(server.mappath(request("src"))) then
call sendFile()
else
call sendError()
end if

end if


response.end

%>