gifImage = Image.FromFile(configPath);
            dimension = new FrameDimension(gifImage.FrameDimensionsList[0]); 
            frameCount = gifImage.GetFrameCount(dimension);
            for (int i = 0; i < frameCount ; i++) //frameCount
            {
                gifImage.SelectActiveFrame(dimension, i);
                gifImage = WriteTextOnImage(gifImage, float.Parse(textSize), textColor, i.ToString(), isObj);
                gifImage.Save(imageStream, ImageFormat.Gif);
            }

    private Image WriteTextOnImage(Image oldBitmap, float sizeText, String textColor, String text, String isObj)
    {
        var graphics = Graphics.FromImage(oldBitmap);      
        Font font = new Font("Arial", sizeText, FontStyle.Bold, GraphicsUnit.Pixel);
        Point atpoint = new Point(oldBitmap.Width / 2, 12);
        Color color = ColorTranslator.FromHtml("#" + textColor); 
        SolidBrush brush = new SolidBrush(color);
        StringFormat sf = new StringFormat();
        sf.Alignment = StringAlignment.Center;
        sf.LineAlignment = StringAlignment.Center;

        graphics.DrawString(text, font, brush, atpoint, sf);
        return oldBitmap;
    }