def convert_la_to_rgba(self, row, result):
        """Convert a grayscale image with alpha to RGBA."""
        for i in range(len(row) // 3):
            for j in range(3):
                result[(4 * i) + j] = row[2 * i]
            result[(4 * i) + 3] = row[(2 * i) + 1]
Convert a grayscale image with alpha to RGBA.