private void decryptImage()
        {
            var headerPixel = HeaderPixel.From(this.EncodedImage.GetPixel(0, 0));

            if (!headerPixel.IsEncrypted)
            {
                return;
            }
            var decrypter = new ImageDecryption(this.ExtractedImage);

            this.ExtractedImage = decrypter.DecryptedImage;
        }
        private void decryptButton_Click(object sender, EventArgs e)
        {
            var image       = (Bitmap)this.largePictureBox.Image;
            var headerPixel = HeaderPixel.From(image.GetPixel(0, 0));

            if (headerPixel.IsImage)
            {
                this.extractImage();
            }
            else
            {
                this.extractText();
            }
        }