how to fill map or blend image in picture box image dynamically select

You can use the following steps:

1. Load the base image into the PictureBox.
2. Allow the user to select an area on the image (you can implement this using mouse events).
3. Create a white texture image dynamically.
4. Blend or add the white texture to the selected area on the base image.

// Assuming you have the base image loaded in pictureBoxBase and the selected area coordinates in selectedArea

Bitmap baseImage = new Bitmap(pictureBoxBase.Image);
Graphics g = Graphics.FromImage(baseImage);

// Create a white texture image
Bitmap whiteTexture = new Bitmap(selectedArea.Width, selectedArea.Height);
using (Graphics gTexture = Graphics.FromImage(whiteTexture))
{
    gTexture.FillRectangle(Brushes.White, 0, 0, selectedArea.Width, selectedArea.Height);
}

// Blend the white texture onto the selected area
g.DrawImage(whiteTexture, selectedArea);

// Update the PictureBox with the modified image
pictureBoxBase.Image = baseImage;