Code:

        private static byte[] ConvertImageToByteArray(System.Drawing.Image imageToConvert, System.Drawing.Imaging.ImageFormat formatOfImage) { 
            byte[] result; 

            try { 
                using (System.IO.MemoryStream ms = new MemoryStream()) { 
                    imageToConvert.Save(ms,formatOfImage); 
                    result = ms.ToArray(); 
                } 
            } catch (System.Exception) { 
                throw;
            } 

            return result; 
        }

        //When you are ready to convert the byte array back to an image, you can include the following code in your method. 
        public void UseImageStoredAsByte(byte[] byteArray) {

            System.Drawing.Image newImage;

            using (System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(byteArray, 0, byteArray.Length)) {
                memoryStream.Write(byteArray, 0, byteArray.Length);
                newImage = System.Drawing.Image.FromStream(memoryStream, true);
                // work with image here. 
                // You'll need to keep the MemoryStream open for 
                // as long as you want to work with your new image. 
            }
        }