How to resize image from memorystream to file?

[BlackRed]

Hello,

I have some images stored in a database, but they are all rather large in dimensions (some are 3000px wide!), and I want to resize them and save them to disk the first time they are requested so my website is not pulling out these massive images every time.

I can pull out the images from the database and can display them just fine by modifying the content type of the the page I am writing them out to - but this is no good obviously because they don't resize and they're not saving to disk for future use.

I've got this far following a tutorial...

Dim imgPhotoVert As System.Drawing.Image = System.Drawing.Image.FromStream(New System.IO.MemoryStream(image.data))
Dim imgPhoto As System.Drawing.Image = Nothing

imgPhoto = FixedSize(imgPhotoVert, Width, Height)
imgPhoto.Save(sbFileName.ToString, System.Drawing.Imaging.ImageFormat.Jpeg)
imgPhoto.Dispose()

Private Function FixedSize(ByVal imgPhoto As System.Drawing.Image, ByVal Width As Integer, ByVal Height As Integer) As System.Drawing.Image
    Dim sourceWidth As Integer = imgPhoto.Width
    Dim sourceHeight As Integer = imgPhoto.Height
    Dim sourceX As Integer = 0
    Dim sourceY As Integer = 0
    Dim destX As Integer = 0
    Dim destY As Integer = 0

    Dim nPercent As Double = 0
    Dim nPercentW As Double = 0
    Dim nPercentH As Double = 0

    nPercentW = Width / sourceWidth
    nPercentH = Height / sourceHeight

    If (nPercentH < nPercentW) Then
        nPercent = nPercentH
        destX = (Width - (sourceWidth * nPercent)) / 2
    Else
        nPercent = nPercentW
        destY = (Height - (sourceHeight * nPercent)) / 2
    End If

    Dim destWidth As Integer = sourceWidth * nPercent
    Dim destHeight As Integer = sourceHeight * nPercent

    Dim bmPhoto As System.Drawing.Bitmap = New Drawing.Bitmap(Width, Height, Drawing.Imaging.PixelFormat.Format24bppRgb)
    bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution)

    Dim grPhoto As System.Drawing.Graphics = Drawing.Graphics.FromImage(bmPhoto)
    grPhoto.Clear(Drawing.Color.Red)
    grPhoto.InterpolationMode = Drawing.Drawing2D.InterpolationMode.HighQualityBicubic

    grPhoto.DrawImage(imgPhoto, New Drawing.Rectangle(destX, destY, destWidth, destHeight), New Drawing.Rectangle(sourceX, sourceY, sourceWidth, sourceHeight), Drawing.GraphicsUnit.Pixel)

    grPhoto.Dispose()
    Return bmPhoto

End Function

But on this line:

imgPhoto2.Save(sbFileName.ToString, System.Drawing.Imaging.ImageFormat.Jpeg)

I get this error:

A generic error occurred in GDI+.

Obviously that's not the all the code, but it's the part that supposed be resizing and saving images!

Can anyone help me out?

Cheers,
Greg.

 

[BlackRed]

You know what folks, never mind! My dumb-ass fault; I wasn't server.mappathing my filename, so this didn't work:

imgPhoto.Save(sbFileName.ToString, System.Drawing.Imaging.ImageFormat.Jpeg)

But this does:

imgPhoto2.Save(Server.MapPath(sbFileName.ToString), System.Drawing.Imaging.ImageFormat.Jpeg)

Doh!