Customer Reviews

Hidden Images: Making Random Dot Stereograms/Book and Disk

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This book was published back in 1994 when random dot stereograms were all the rage. Random-dot stereograms are composed of (colored) dots which when viewed correctly appear three-dimensional. Thus at first glance you think you see just a random pattern, but when viewed "just right" you might see a spaceship, or a teapot, or whatever the artist has buried in the image. These images were first described in an issue of "Stereo World" magazine in 1989, and had largely fallen from fad status by the end of the 1990's.

This book is really very good at describing the algorithms involved in creating the images. The first three chapters introduce the concept and discuss what makes the random dot stereogram have its "dual" appearance, including how your brain cooperates in the process. The fourth chapter is what gives the book value after 12 years, since it has the process broken down into algorithms with numbered steps that can easily be turned into code that performs the task. Chapter five is a companion to chapter four since it describes the "adjustable parameters" of a program that creates random dot stereograms such as pattern width, pixel density, and depth factor. Chapter six consists of advanced topics and brings up additional features you can add to your program to create more sophisticated images. Chapters 7-10 have some useful information, but because of the age of the book it is largely talking about using obsolete software such as Paintbrush for depth image creation, Polyray for ray tracing, and the included software of the book, Pop-Out Lite, as tools.

Thus I subtract a single star just for the age of the software being referenced and the fact that not a single line of code exists in the book, even though there are enough algorithmic details you can easily write your own in the programming language of your choice. Also, make sure you or an acquaintance knows how to look at these images, or else you will never know if you coded up any of the algorithms correctly. I coded up the algorithms in this book in Java and found it to be a pretty interesting project.