We　investigate　the　application　of　quantum　cellular　automata　in　image　encryption　and　propose　a　novel　quantum　gray-scale　image　encryption　algorithm　based　on　one-dimensional　quantum　cellular　automata.　The　quantum　image　encryption　algorithm　can　be　realized　by　subtly　constructing　the　evolution　rules　of　one-dimensional　quantum　cellular　automata.　Because　all　quantum　operations　are　invertible,　the　quantum　image　decryption　algorithm　is　the　inverse　of　the　encryption　algorithm.　The　proposed　quantum　image　encryption　algorithm　has　an　algorithm　complexity　of　Theta(n),　lower　than　the　algorithm　complexity,　Theta(n(2))　of　existing　quantum　image　encryption　schemes　based　on　quantum　Fourier　transform.　Supported　by　detailed　numerical　simulation　and　theoretical　analysis,　our　proposal　has　outperformed　its　classical　counterpart　and　other　image　encryption　schemes　in　terms　of　the　security,　computational　complexity,　and　robustness.　And　it　also　provides　a　clue　of　introducing　quantum　cellular　automata　into　image　encryption.　(C)　2016　Elsevier　Inc.　All　rights　reserved.