Image Resize Whitespace/Blackspace issue.. weird! RRS feed

  • Question

  • User635479908 posted

    Hey all,

    I am using this code to resize an image to a static size, and i used to use newGraphic.Clear(Color.White), which used to leave a bunch of the sides or tops with some white space.  I now use newGraphic.Clear(Color.Transparant) which acctually works fine on my local development pc, it sizes it perfectly and clears off the pixels on the side.  However when i upload it to my server, it adds black where the whitespace used to be.  I just dont get it! ive tried this on 3 different servers now and its the same thing!

    Here's my code:


     Private Sub Pic(ByVal fu As Telerik.Web.UI.RadUpload, ByVal index As UploadedFile)
            Const bmpW = 300 'New image target width
            Const bmpH = 256 'New Image target height
            errlabel.Text = ""
            Dim newWidth As Integer = bmpW
            Dim newHeight As Integer = bmpH
            Dim upName As String = DateTime.UtcNow.Ticks & ".png"
            Dim filePath As String = "C:\" & upName
            Dim upBmp As Bitmap = Bitmap.FromStream(index.InputStream)
            Dim newBmp As Bitmap = New Bitmap(newWidth, newHeight, Imaging.PixelFormat.Format24bppRgb)
            newBmp.SetResolution(72, 72)
            Dim upWidth As Integer = upBmp.Width
            Dim upHeight As Integer = upBmp.Height
            Dim newX As Integer = 0 'Set the new top left drawing position on the image canvas
            Dim newY As Integer = 0
            Dim reDuce As Decimal
            If upWidth > upHeight Then 'Landscape picture
                reDuce = newWidth / upWidth
                newHeight = Int(upHeight * reDuce)
                newY = Int((bmpH - newHeight) / 2)
                newX = 0 'Picture will be full width
            ElseIf upWidth < upHeight Then 'Portrait picture
                reDuce = newHeight / upHeight
                newWidth = Int(upWidth * reDuce)
                newX = Int((bmpW - newWidth) / 2)
                newY = 0 'Picture will be full hieght
            ElseIf upWidth = upHeight Then 'square picture
                reDuce = newHeight / upHeight
                newWidth = Int(upWidth * reDuce)
                newX = Int((bmpW - newWidth) / 2) 'Position the image centrally across the canvas
                newY = Int((bmpH - newHeight) / 2) 'Position the image centrally down the canvas
            End If
            Dim newGraphic As Graphics = Graphics.FromImage(newBmp)
                newGraphic.SmoothingMode = Drawing2D.SmoothingMode.AntiAlias
                newGraphic.InterpolationMode = Drawing2D.InterpolationMode.HighQualityBicubic
                newGraphic.DrawImage(upBmp, newX, newY, newWidth, newHeight)
                newBmp.Save(filePath, Imaging.ImageFormat.Png)
                lblpic.Text = "/lstimages/" & upName
            Catch ex As Exception
                errlabel.Text = ex.ToString
            End Try
        End Sub
    Monday, March 30, 2009 1:54 PM

All replies

  • User1396024914 posted

    hi Mnemonic

    check this out to resize image:


    Don't forogt to mark as answer

    Tuesday, September 29, 2009 2:42 PM
  • User1176561268 posted


    You can resize the image using the following code..

                 string displayedImghead;
                //Get the path of the original Image
                displayedImghead = Server.MapPath("~/Admin/Banner/Thumbnail/") + FUHead.FileName;
            // Get the path of the Thumb folder
            string displayedImgThumbhead = Server.MapPath("~/Admin/Banner/");
            // Get the original image file name
            string imgFileNamehead = System.IO.Path.GetFileName(displayedImghead);

            // Load original image
            System.Drawing.Image myimghead = System.Drawing.Image.FromFile(displayedImghead);
            // Get the thumbnail size px
            myimghead = myimghead.GetThumbnailImage(468, 60, null, IntPtr.Zero);

            // Save the new thumbnail image
            myimghead.Save(displayedImgThumbhead + imgFileNamehead, myimghead.RawFormat);

    Hope It Helps....Please mark as answer if useful



    Sharma Infoway

    Friday, October 9, 2009 2:32 AM