Question

What i am trying to do is to convert an image into a byte array and then write that byte array into a file. here’s the code

public static byte[] Convert(Image img)
    {
        using (MemoryStream ms = new MemoryStream())
        {
            img.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
            // or whatever output format you like
            return ms.ToArray();
        }
    }

    public Form1()
    {
        InitializeComponent();
        Bitmap pic = new Bitmap("tulips.jpg");
        pictureBox1.Image = pic;
        byte[] img_array;
        img_array = Convert(pic);
        File.WriteAllBytes("test.txt", img_array);

    }

Now I have been successfully able to convert the image into byte array. I have checked the values in byte array by means of a breakpoint and all of them are valid.

However when I try to write the array into a file and then open the file all I see is garbage.

Am I missing something?

Answer 1

Your Bitmap is an Image. Why do you convert it into a byte array when you can simply call Save (documented here)

Bitmap pic = new Bitmap("tulips.jpg");
pictureBox1.Image = pic;
pic.Save("test.gif", System.Drawing.Imaging.ImageFormat.Gif); 

To manipulate the image, you will usually access the pixel data – what you have now contains the file type header as well as the pixels! See Bitmap.LockBits to manipulate the pixels (documented here)