An image encryption approach based on an invertible two-dimensional map by construction triangle
Juan Li · Journal of Optoelectronics·laser · 2009
By constructing an isosceles triangle,the paper proposes a new invertible two-dimensional map which can encrypt rectangle images.by processing image stretch-and-fold.Firstly,pixels of plain-image are constructed to a virtual isosceles triangle where the pixels of each row are added one by one.Then the pixels of the odd row are inserted into adjacent two pixels of the even row,and the triangle is stretched to a line of pixels.Lastly,the line is folded over to a new image with the same size to the plain-image.The map shuffles the positions of image pixels,and it is invertible.The simulation results show that the proposed encryption approach is valid.Analysis shows that the map can also encrypt compressed images or arbitrary length of data sets.