How to convert image between different format?

/// <summary>
/// Convert image file to certain format
/// </summary>
/// <param name="fromImageFullPath">The original image file</param>
/// <param name="toImageFullPath">The new image file</param>
/// <param name="mimeType">The format of the new image file, i.e. "image/bmp", "image/jpeg"</param>
public static void ConvertImage(string fromImageFullPath, string toImageFullPath, string mimeType)
{
    try
    {
        // Read the content of the image file into a bitmap variable
        Stream fromFile = File.OpenRead(fromImageFullPath);
        Image image = Image.FromStream( fromFile, true ) ;
        Bitmap bitmap = (Bitmap) image;
        // Instantiate the encoder
        EncoderParameters encoderParams = new EncoderParameters();
        encoderParams.Param[0] = new EncoderParameter( Encoder.Quality, 50L );
        ImageCodecInfo codecInfo = GetEncoderInfo( mimeType );
        // Covert the image to the new format
        MemoryStream newImage = new MemoryStream();
        bitmap.Save( newImage, codecInfo, encoderParams );
        // Write the new image into a file
        byte[] data = newImage.ToArray();
        Stream toFile = File.OpenWrite( toImageFullPath );
        toFile.Write(data,0,data.GetLength(0));
        fromFile.Close();
        toFile.Close();
    }
    catch(Exception ex)
    {
        ...
    } 
}



/// <summary>
/// Get encoder infor
/// </summary>
/// <param name="mimeType">the codec's Multipurpose Internet Mail Extensions (MIME) type</param>
/// <returns>All pertinent information about the installed image codecs</returns>
private static ImageCodecInfo GetEncoderInfo(String mimeType)
{
    int j;
    ImageCodecInfo[] encoders;
    encoders = ImageCodecInfo.GetImageEncoders();
    for(j = 0; j < encoders.Length; ++j)
    {
        if(encoders[j].MimeType == mimeType)
            return encoders[j];
    }
    return null;
}