Image representation has always been a basic problem in image processing. This paper studies the approach of a digital image expressed as a complex number. The new approach has been applied to image disguise

and the result is satisfying. A one-to-one correspondence established between an image and a point in a complex plane based on complex bases under positional number system notation. The relationships between different images can be converted into a plain vector operation

which helps image study using geometric method. Thus

a new image disguise method is realized. This image disguise algorithm can not only disguise one or many images

but also allows an image to be disguised many times. Experimental results show that our method is numerically stable

can accurately restore secret images in an ideal transmission environment

and can restore secret images with some satisfaction even in a noisy transmission environment.