Remove top and bottom padding from Text drawn on an Image

Question

I am generating images from specified text but there is a problem I'm facing: I cannot remove the top and bottom padding of the drawn Text inside the image I generate.

I tried to change string format while using Graphics.DrawString(), but I only managed to remove the left and right padding.

private void button1_Click(object sender, EventArgs e)
{
    Font font = new Font("Arial", 52, FontStyle.Regular);
    Image i = GetTextAsImage(textBox1.Text,400, font, Color.Black, Color.LightGray);
    i.Save("myImage.jpeg", ImageFormat.Jpeg);
}

private Image GetTextAsImage(String text, int widthInPixel, Font textFont, Color textColor, Color backColor)
{
    //first, create a dummy bitmap just to get a graphics object
    Image img = new Bitmap(1, 1);
    Graphics drawing = Graphics.FromImage(img);

    //measure the string to see how big the image needs to be
    SizeF textSize = drawing.MeasureString(text, textFont);

    //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, textFont.Height);

    drawing = Graphics.FromImage(img);
    drawing.SmoothingMode = SmoothingMode.AntiAlias;
    drawing.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
    //paint the background
    drawing.Clear(backColor);
    //create a brush for the text
    Brush textBrush = new SolidBrush(textColor);
    drawing.DrawString(text, textFont, textBrush, 0, 0,StringFormat.GenericTypographic);

    drawing.Save();
    textBrush.Dispose();
    drawing.Dispose();
    return img;
}

This is the Output I get:

This is the expected output:

Answer 1

I propose you a slightly different method, using the GraphicsPath class to both measure and draw the text on a Bitmap object.

The advantage is that the GraphicsPath class reports the actual coordinates where the object(s) that it contains will be drawn and also the size of the text, in relation to a specific Font.
These measures are returned in a RectagleF structure, calling the GraphicsPath.GetBounds() method.
The base constructor assumes a Pen size of 1 pixel.

There's only one (small) detail to take care of: the GDI+ Bitmap object accepts dimensions expressed in integer values only, while all the other measures are expressed in floating point values.
We need to compensate for the rounding, but it's usually just ± 1 pixel.

Sample of the results:

A description of the procedure:

• Define a Font Family and Size
• Add the Text string to the GraphicsPath object
• Get the GraphicsPath bounding rectangle of the text object
• Build a Bitmap object using the bounding rectangle Size
• Move the World coordinates, with Graphics.TranslateTransform, to the coordinates defined by the bounding rectangle Y position and the Pen Size, using their negative value: we need to move backwards that measure.
• Draw the Text

See also these notes about GraphicsPath and Fonts:
Properly draw text using Graphics Path

Sample code:

using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Drawing.Text;


string text = "This is my Text";
Font font = new Font("Arial", 52, FontStyle.Regular, GraphicsUnit.Point);
float penSize = 1f;

using (var path = new GraphicsPath()) {
    path.AddString(text, font.FontFamily, (int)font.Style, font.Size, Point.Empty, StringFormat.GenericTypographic);

    RectangleF textBounds = path.GetBounds();

    using (var bitmap = new Bitmap((int)textBounds.Width, (int)textBounds.Height, PixelFormat.Format32bppArgb))
    using (var g = Graphics.FromImage(bitmap)) 
    using (var brush = new SolidBrush(Color.LightGreen)) {
        g.SmoothingMode = SmoothingMode.AntiAlias;
        // When rendering without a GraphicsPath object
        //g.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;
        g.Clear(Color.Black);
        g.TranslateTransform(-(textBounds.X + penSize), -(textBounds.Y + penSize));
        g.FillPath(brush, path);
        
        bitmap.Save("[Image Path]", ImageFormat.Png);
        // Or: return (Bitmap)bitmap.Clone();
        // Or: return bitmap; declaring the bitmap without the using statement
    }
}