Image Resized Thumbnail

[MarkZK]

Hi all,

I used "NoCoolHandle"'s code from this thread ...

http://tek-tips.com/viewthread.cfm?qid=1155023

which does work, but can anyone tell me why the thumbnails being made are around five time bigger (in file size) than the original, it's VERY odd!.

test.jpg 640x480 - 38KB
test_thumb.jpg 320x240 - 168KB

			'Create Thumbnail
			    Dim thumbnail As System.Drawing.Image
				Dim image As System.Drawing.Image = System.Drawing.Image.FromFile(path)
				thumbnail = ScaleImage(image, 320, 240)
				thumbnail.Save(Server.MapPath(AppPath & "/Images/Thumbs/" & imgName & "_thumb.jpg"))

function..

    Function ScaleImage(ByVal imgFull As Image, ByVal intX As Integer, ByVal intY As Integer) As Image

        Dim dblScaleFactor As Double
        Dim dblScaleX, dblScaleY As Double

        dblScaleX = intX / imgFull.Width
        dblScaleY = intY / imgFull.Height

        If dblScaleX > dblScaleY Then
            dblScaleFactor = dblScaleX
        Else
            dblScaleFactor = dblScaleY
        End If

        Dim scale_factor As Single = CType(dblScaleFactor, Single)

        Dim imgBMP_dest As New Bitmap(CInt(imgFull.Width * scale_factor), CInt(imgFull.Height * scale_factor))

        Dim imgOutput As Graphics = Graphics.FromImage(imgBMP_dest)
        imgOutput.DrawImage(imgFull, 0, 0, imgBMP_dest.Width + 1, imgBMP_dest.Height + 1)

        imgOutput.Dispose()
        imgOutput = Nothing

        Return imgBMP_dest

    End Function

Am I doing something wrong ?, is there a better way to keep some quality and get a smaller file size ?...

Any ideas would be great, thanks.

 

[MarkZK]

I'll answer my own question .... it shoud have been..

thumbnail.Save(Server.MapPath(AppPath & "/Images/Thumbs/" & imgName & "_thumb.jpg"), System.Drawing.Imaging.ImageFormat.Jpeg)

I guess it wasn't compressing the image to a jpg file, I also missed some cleaning up (.Dispose())