将图像1的像素设置为透明以显示图像1后面的图像

Question

The program that I am working on requires that I layer two images on top of each other (z indexes will be 1 number apart). The top layer is a black image(png) and the bottom layer is a normal image that you would pull from google. Let's say I pull a set of pixels from a database that had been previously entered(100 pixels for example); I want those 100 pixels to turn transparent. My current code is responding by changing the pixel to plain white. Anyone have any suggestions?

This code snippet represents specific pixels being pulled from a database.

DataSet ds = new DataSet();
        SqlCommand sqlRead = new SqlCommand("SELECT * FROM PIXEL", con);
        List<int> pixelIds = new List<int>();

        using (SqlDataReader read = sqlRead.ExecuteReader())
        {
            while (read.Read())
            {
                int pixel = Convert.ToInt32(read[0]);
                pixelIds.Add(pixel);
                int yaxis = Convert.ToInt32(pixel) / 1000;
                int xaxis = Convert.ToInt32(pixel) % 1000;
                image1.SetPixel(xaxis, yaxis, Color.Transparent);
            }
        }

Answer 1

Solved. What I had to do was change the Color.Transparent to Color.Brown then wrote image1.MakeTransparent(Color.Brown) below that which worked perfectly. Thank you all for the responses.