c# - 为字幕添加高度到图像

Question

我想为图像添加一个额外的高度来给它一个字幕。我不想“压缩”或调整我的原始图像。我想保持它的大小并在底部的高度上添加 +40 px 并添加一个像这个例子一样的文本

红色部分是原始图像。蓝色部分是我的补充。

我尝试了这段代码，但我的文字出现在我认为的图像“外部”。

Image image = Image.FromFile("D:\\my_sample_image.jpg");
// Create graphics from image
Graphics graphics = Graphics.FromImage(image);
// Create font
Font font = new Font("Times New Roman", 42.0f);
// Create text position
PointF point = new PointF(150, image.Height+40);
// Draw text
graphics.DrawString("Watermark", font, Brushes.Red, point);
// Save image
image.Save("D:\\my_sample_output.jpg");
MessageBox.Show("FINISHED");
// Open generated image file in default image viewer installed in Windows
Process.Start("D:\\my_sample_output.jpg");

Answer 1

制作一个新的位图，从中创建一个图形，然后在底部绘制带有文本空间的旧图像。

Bitmap image = new Bitmap("path/resource");
Bitmap newImage = new Bitmap(image.Width, image.Height + 40);
using (Graphics g = Graphics.FromImage(newImage))
{
      // Draw base image
      Rectangle rect = new Rectangle(0, 0, image.Width, image.Height); 
      g.DrawImageUnscaledAndClipped(image, rect);
      //Fill undrawn area
      g.FillRectangle(new SolidBrush(Color.Black), 0, image.Height, newImage.Width, 40);
      // Create font
      Font font = new Font("Times New Roman", 22.0f);
      // Create text position (play with positioning)
      PointF point = new PointF(0, image.Height);
      // Draw text
      g.DrawString("Watermark", font, Brushes.Red, point);
 }

Answer 2

public Image addSubtitleToImage(string path, int height, string title)
{
    Bitmap image = new Bitmap(path);
    Bitmap newImage = new Bitmap(image.Width, image.Height + height);
    using (Graphics g = Graphics.FromImage(newImage))
    {
        g.FillRectangle(new SolidBrush(Color.Black), new Rectangle(0, 0,   newImage.Width, newImage.Height));
        g.DrawImage(image, new Rectangle(0, 0, image.Width, image.Height));

        Font font = new Font("Tahoma", 30.0f);
        g.DrawString(title, font, Brushes.White, new PointF(image.Width/2 , image.Height+));

    }
    return newImage;
}