主题：[求助]如何修改图片的位深度

mark 缩放图片

Dim file As String = "d:\test.jpg"
Dim img As image = getImage(file)
Dim bmp As bitmap
If img.width > 800 Then
    If 800 * (img.height / img.width) > 600 Then
        bmp = new bitmap(img, 800*(600/(800*(img.height/img.width))), 600)
    Else
        bmp = new bitmap(img, 800, 800 * (img.height / img.width))
    End If
End If
bmp.save("d:\缩略图.jpg")
bmp.Dispose