Imports System.Drawing.Imaging Sub SaveJPG() Dim Image as Bitmap = New Bitmap(OrigianalImageFile) '設定壓縮品質90檔案大小約是100的一半 但是畫質還是很不錯 Dim quality As Integer = 90 Dim qualityParam As New EncoderParameter(Encoder.Quality, quality) '取得編碼格式 Dim jgpEncoder As ImageCodecInfo = GetEncoder(ImageFormat.Jpeg) Dim encoderParams As New EncoderParameters(1) encoderParams.Param(0) = qualityParam Image.Save(NewImageFile, jgpEncoder, encoderParams) End Sub '取得編碼格式的副程式 Private Function GetEncoder(ByVal format As ImageFormat) As ImageCodecInfo Dim codecs As ImageCodecInfo() = ImageCodecInfo.GetImageDecoders() Dim codec As ImageCodecInfo For Each codec In codecs If codec.FormatID = format.Guid Then Return codec End If Next codec Return Nothing End Function 參考資料： MSDN