How can I add extra text as new part of existing image gif?

Question

I have this image in the original :

I want to edit the gif by code and to add a text to it at the bottom and make the text as part of the gif image.

For example like this :

I marked with red the gray background and the text I want to add to the first image, this is what I mean the gray part and the text the time and date.

Marked in red at the bottom to show what I mean by adding the gray background and the text.

The text at the bottom the date and time I want to add it to the gif image the first gif image I show here only the text or also part of the gray background but something like the second image.

To add more pixels or something as the gray background at the bottom and then write on it the text the time and date and then to save the original gif with the made changes.

The second image here is just example of what I want to archive on the first image.

The text is not matter now what it will be but I want to be able to edit the gif add some text at the bottom as part of it and save the gif.

What I tried so far :

Created a new class with this code :

using System;  
using System.Collections.Generic;  
using System.Drawing;  
using System.Drawing.Text;  
using System.Text;  
  
namespace Wpf_Download_Files  
{  
    class DrawOnImage  
    {  
        public Image DrawText(String text, String subText, Image img)  
        {  
            var textColor = Color.Black;  
            var backColor = Color.Transparent;  
  
            var textFont = new Font("Arial", 15);  
            Brush textBrush = new SolidBrush(textColor);  
  
            var subTextFont = new Font("Arial", 7);  
            Brush subTextBrush = new SolidBrush(textColor);  
  
            //first, create a dummy bitmap just to get a graphics object  
            img = new Bitmap(img);  
            Graphics drawing = Graphics.FromImage(img);  
  
            //measure the string to see how big the image needs to be  
            SizeF textSize = drawing.MeasureString(text, textFont);  
            SizeF subTextSize = drawing.MeasureString(subText, subTextFont);  
  
            //free up the dummy image and old graphics object  
            img.Dispose();  
            drawing.Dispose();  
  
            //create a new image of the right size  
            img = new Bitmap(((int)textSize.Width + (int)subTextSize.Width) - ((int)textSize.Width / 3), (int)textSize.Height + 15);  
  
            drawing = Graphics.FromImage(img);  
            drawing.TextRenderingHint = TextRenderingHint.SingleBitPerPixelGridFit;  
  
            //paint the background  
            drawing.Clear(backColor);  
  
            //Draw Text  
            drawing.DrawString(text, textFont, textBrush, 5, 0);  
  
            //Drawing Line  
            var linePen = new Pen(Color.Black, 3);  
            var height = (int)textSize.Height;  
            var width = (int)textSize.Width;  
  
            drawVerticalLine(drawing, linePen, 1, 0, height + 5);  
            drawHorizontalLine(drawing, linePen, 0, height + 5, width / 3);  
  
            //Darw Subtext  
            drawing.DrawString(subText, subTextFont, subTextBrush, width / 3, height);  
  
            drawing.Save();  
  
            textBrush.Dispose();  
            drawing.Dispose();  
  
            return img;  
        }  
  
        private void drawHorizontalLine(Graphics graphics, Pen pen, int x, int y, int width)  
        {  
            graphics.DrawLine(pen, x, y, x + width, y);  
        }  
  
        private void drawVerticalLine(Graphics graphics, Pen pen, int x, int y, int height)  
        {  
            graphics.DrawLine(pen, x, y, x, y + height);  
        }  
    }  
}  

And in the main form I did :

public MainWindow()  
        {  
            InitializeComponent();  
  
            System.Drawing.Image img =  
                System.Drawing.Image.FromFile(@"d:\Downloaded Images\Image0.gif");  
            DrawOnImage drawonimage = new DrawOnImage();  
            drawonimage.DrawText("Hello World", "utt 12345", img);  

Answer 1

I forgot to mention that I'm using wpf not winforms if it's important.

A way in WPF :

BitmapImage bi = new BitmapImage();
bi.BeginInit();
bi.UriSource = new Uri(@"E:\Hulk.gif", UriKind.RelativeOrAbsolute);
bi.EndInit();

string sText = "This is a text";
int nTextHeight = 60;
DrawingVisual drawingVisual = new DrawingVisual();
using (DrawingContext drawingContext = drawingVisual.RenderOpen())
{
    drawingContext.DrawImage(bi, new Rect(0, 0, bi.Width, bi.Height));

    Rect rect = new Rect(0, bi.Height, bi.Width, nTextHeight);
    drawingContext.DrawRectangle(System.Windows.Media.Brushes.LightGray, new Pen(Brushes.Red, 2), rect);                   

    var formattedText = new FormattedText(sText, System.Globalization.CultureInfo.InvariantCulture,
        FlowDirection.LeftToRight,
        new Typeface("Arial"), 12, Brushes.Red);
    formattedText.TextAlignment = TextAlignment.Center;
    double nX = bi.Width / 2; 
    double nY = bi.Height + nTextHeight / 2;                    
    Point pt = new Point(nX, nY - formattedText.Height / 2);
    drawingContext.DrawText(formattedText, pt); 
}
RenderTargetBitmap bmp = new RenderTargetBitmap((int)bi.Width, (int)bi.Height + nTextHeight, 96, 96, PixelFormats.Pbgra32);
bmp.Render(drawingVisual);

GifBitmapEncoder gif = new GifBitmapEncoder();
gif.Frames.Add(BitmapFrame.Create(bmp));                
using (System.IO.Stream stm = System.IO.File.Create(@"E:\Hulk_2.gif"))
{
    gif.Save(stm);
}

Answer 2

For example =>

Original :

New :

System.Drawing.Image img = System.Drawing.Image.FromFile("E:\\Hulk.gif");  
int nWidth = img.Width;  
int nHeight = img.Height;  
int nTextHeight = 60;  
  
Bitmap bmp = new Bitmap(nWidth, nHeight + nTextHeight, System.Drawing.Imaging.PixelFormat.Format32bppArgb);  
using (Graphics g = Graphics.FromImage(bmp))  
{  
    g.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceOver;  
    g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;  
    g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBilinear;  
    g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;  
    g.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;  
  
    g.DrawImage(img, new Rectangle(new Point(), img.Size), new Rectangle(new Point(), img.Size), GraphicsUnit.Pixel);  
    string sText = "This is a text";  
    using (Font font = new Font("Arial", 12, System.Drawing.FontStyle.Regular, GraphicsUnit.Point))  
    {  
        Rectangle rect = new Rectangle(0, nHeight, nWidth, nTextHeight);  
        g.FillRectangle(System.Drawing.Brushes.LightGray, rect);  
        g.DrawRectangle(Pens.Red, rect);  
        StringFormat stringFormat = new StringFormat();  
        stringFormat.Alignment = StringAlignment.Center;  
        stringFormat.LineAlignment = StringAlignment.Center;  
        g.DrawString(sText, font, Brushes.Red, rect, stringFormat);                     
    }  
}  
  
bmp.Save("E:\\Hulk2.gif", System.Drawing.Imaging.ImageFormat.Gif);  
// Test in a PictureBox  
pictureBox1.SizeMode = PictureBoxSizeMode.AutoSize;  
pictureBox1.Image = bmp;