Calculated Image

A billion years ago I found a one liner in a magazine and it made a pretty cool image. Recently I found it again and thought it would be cool to try it on a modern computer. Below is the algorithm I came up with. Just drop a Picture Box onto a form, add an X, Y and Decimal (from .2 to .9):

// Created by Gregg Buntin
private void DrawImage()
{
    int sizeX = Convert.ToInt32(tbX.Text); // this is the X (width) of the image
    int sizeY = Convert.ToInt32(tbY.Text); // this is the Y (height) of the image
    int halfX = sizeX / 2;
    int halfY = sizeY / 2;
    calculatedImage = new Bitmap(sizeX, sizeY);
    Color tempColor = new Color();
    double num = Convert.ToDouble(tbDec.Text); // This is where you plug in the Decimal value
    for (int Y = -(halfY); Y < 1; Y++)
    {
        int Y2 = Y * Y;
        for (int X = -(halfX); X < 1; X++)
        {
            tempColor = Color.White;
            double tempR = Math.Pow((Y2 + (X * X)), num);
            double R = (10000000 - tempR) / 2;
            int intR = Convert.ToInt32(R);
            double roundR = Math.Truncate(R);
            if (roundR != intR) tempColor = Color.Black;
            int X1 = X + halfX;
            int Y1 = Y + halfY;
            calculatedImage.SetPixel(X1, Y1, tempColor);
            calculatedImage.SetPixel(sizeX - 2 - X1, Y1, tempColor);
            calculatedImage.SetPixel(X1, sizeY - 2 - Y1, tempColor);
            calculatedImage.SetPixel(sizeX - 2 - X1, sizeY - 2 - Y1, tempColor);
        } // for X
    } // for Y
    pbImage.Image = calculatedImage;
} // method DrawImage