画像をセピア色に変換する方法

画像をセピア色に変換する方法
VB.NET

Public Shared Function CreateSepiatoneImage(ByVal img As Image) As Image

    Dim newImg As New Bitmap(img.Width, img.Height)

    Dim g As Graphics = Graphics.FromImage(newImg)

    Dim cm As New System.Drawing.Imaging.ColorMatrix( _
        New Single()() { _
            New Single() {0.393F, 0.349F, 0.272F, 0, 0}, _
            New Single() {0.769F, 0.686F, 0.534F, 0, 0}, _
            New Single() {0.189F, 0.168F, 0.131F, 0, 0}, _
            New Single() {0, 0, 0, 1, 0}, _
            New Single() {0, 0, 0, 0, 1}})

    Dim ia As New System.Drawing.Imaging.ImageAttributes()

    ia.SetColorMatrix(cm)

    g.DrawImage(img, New Rectangle(0, 0, img.Width, img.Height), _
                0, 0, img.Width, img.Height, GraphicsUnit.Pixel, ia)

    g.Dispose()

    Return newImg
End Function

C#

public static Image CreateSepiatoneImage(Image img)
{

    Bitmap newImg = new Bitmap(img.Width, img.Height);

    Graphics g = Graphics.FromImage(newImg);

    System.Drawing.Imaging.ColorMatrix cm =
        new System.Drawing.Imaging.ColorMatrix(
            new float[][] {
                new float[] {.393f, .349f, .272f, 0, 0},
                new float[] {.769f, .686f, .534f, 0, 0},
                new float[] {.189f, .168f, .131f, 0, 0}, 
                new float[] {0, 0, 0, 1, 0},
                new float[] {0, 0, 0, 0, 1}
            });

    System.Drawing.Imaging.ImageAttributes ia =
        new System.Drawing.Imaging.ImageAttributes();

    ia.SetColorMatrix(cm);

    g.DrawImage(img,
        new Rectangle(0, 0, img.Width, img.Height),
        0, 0, img.Width, img.Height, GraphicsUnit.Pixel, ia);

    g.Dispose();

    return newImg;
}