Abstract Present paper introduces a polynomial combination of one dimensional chaotic maps that is blended in a dynamic image encryption algorithm. It is special because not only this combination has butterfly folding effect but also it shows generalization property over any polynomial combination. Hence, the butterfly folding effect is caused by governed parameters of polynomial combination. Moreover, multiple simulations and evaluations show the superiority of the proposed chaotic system. An application of this system, which we propose in cryptography, is a novel image encryption algorithm based on dynamic function generation. Compared to the state of the art algorithms, our image encryption algorithm has higher statistical and cryptanalytic properties. Even though this algorithm is not suitable for real-time applications such as streaming video encryption, it makes a good use of the proposed chaotic system. Uppermost cryptanalytic properties that are proven by statistical/numeric tests show good performance and reliability of proposed algorithm for image encryption tasks while unlike any other chaotic image encryption system, our algorithm uses a string input for secret key.