Transparent Layer On Image

using System.Drawing.Drawing2D;

privatestaticImage fill_layer(PictureBox Pic_Box,Image img,Color Layer_color,int Percent)
{
//از img به عنوان بک آپ استفاده می شود
//percent درصد شفافیت است
Pic_Box.Image = img;
Bitmap bmp_img = newBitmap(Pic_Box.Image);
Graphics ghp = Graphics.FromImage(bmp_img);
LinearGradientBrush LineaBrush;
LineaBrush = newLinearGradientBrush(newRectangle(0, 0, bmp_img.Width, bmp_img.Height), Color.FromArgb(Percent, Layer_color), Color.FromArgb(Percent, Layer_color), LinearGradientMode.BackwardDiagonal);
ghp.FillRectangle(LineaBrush, newRectangle(0, 0, bmp_img.Width, bmp_img.Height));
return (Image)bmp_img;
}

pictureBox1.Image = fill_layer(pictureBox1,pictureBox2.Image, Color,Value);

Transparent layer

private void button2_Click(object sender, EventArgs e)
        {
            Random r = new Random();
            Bitmap b = new Bitmap(Width, Height);
            Graphics g = Graphics.FromImage(b);
            SolidBrush br = new SolidBrush(Color.FromArgb(150, r.Next(255),
                r.Next(255), r.Next(255)));
            g.FillRectangle(br,0,0,Width,Height);
            pictureBox1.Image = b;
        }

Transparent Control - %

control.BackColor = Color.FromArgb(trancparency, control.BackColor);

Transparent Control

control.BackColor = Color.Transparent;

Transparent Circle Painting

bool b = false;
        int x1, y1 = 0;
        private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
            if (b == true)
            {
                SolidBrush sb = new SolidBrush(Color.White);
                Bitmap bi = new Bitmap(Width, Height);
                Graphics g = Graphics.FromImage(bi);
                int xx = e.X - x1;
                int yy = e.Y - y1;
                g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
                g.DrawEllipse(new Pen(sb), new Rectangle(x1, y1, xx, yy));
                sb.Color = Color.FromArgb(150, 255, 0, 0);
                g.FillEllipse(sb, new Rectangle(x1, y1, xx, yy));
                pictureBox1.Image = bi;

            }
        }

        private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
        {
            b = false;
        }

        private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
        {
            b = true;
            x1 = e.X;
            y1 = e.Y;
        }