SIS - Single Image Stereogram generator

SIS is a program for generating pictures with a 3-dimensional effect which can be perceived without using any supplementary technical devices. At a first glance a SIS image looks like random patterns or noise, but if you know how to view them correctly you can see a 3-dimensional shape in it. This can be achieved by converging your eyes to look at a more distant point behind the screen while focusing at the distance of the screen. However, it needs a little training. If you know those "Magic Eye" books, you know what to do. Here's an example:

By default, the background of the SIS is made of random black and white dots but you can also set a colored texture-map instead. The depth information of the 3-D objects can be read from a grayscale image. Examples of depth-maps are provided in the repo. The most far distance in the depth-map is coded as black while the nearest points should be white. Depth-maps can be created with a ray-tracer or 3D-modeling software.

Supported file formats

• png, bmp, gif, pnm, tga, jpeg for input and texture. Currently, tif support is disabled and there are some limitations on the accepted image types, basically an 8-bit color palette png should work. These limitations might be removed in future releases.
• output is always png

Requirements

• gcc, make, otherwise no dependencies

Installation

Build from sources:

• Edit the Makefile to change where you might want to install the binary and man-page.
• Run 'make'.
• Run 'make install' to install the binary and man-page (as root). Instead of installing, you can also run the sis excecutable directly from the src directory.

Usage

Generate a SIS of a simple 3-D sinus oval figure which is supplied in the depthmaps subdirectory:

 ./sis ../depthmaps/oval.png out.png

Invoked with the -m option, sis adds two triangles to the top of the picture, which help you to find the right convergence.

 ./sis ../depthmaps/oval.png out.png -m

Use a texture instead of the random noise background:

 ./sis ../depthmaps/oval.png out.png -t ../textures/cork.png

To see all available options run sis without any arguments.

Printing a SIS

You can size and choose the resolution of your SIS with the -x, -y options. For example, if your printer has 300dpi, use:

 ./sis ../depthmaps/oval.png out.png -x40i300 -y30i300

which gives a picture of size 4x3 inch at 300 dpi. Note that 40 means 40 tenths of an inch = 4 inch.

Let me know if you have any suggestions, bugs, improvements, questions, new SIS-algorithms, fancy depth- and texture-maps.