Autostereogram - Terminology

Terminology

• Stereogram and autostreogram

Stereogram was originally used to describe as a pair of 2D images used in stereoscope to present a 3D image to viewers. The "auto" in autostereogram describes an image that does not require a stereoscope. The term stereogram is now often used interchangeably with autostereogram. Dr. Christopher Tyler, inventor of the autostereogram, consistently refers to single image stereograms as autostereograms to distinguish them from other forms of stereograms.

• Random dot stereogram (RDS)

Random dot stereogram, describes a pair of 2D images containing random dots which, when viewed with a stereoscope, produced a 3D image. The term is now often used interchangeably with random dot autostereogram.

• Single image stereogram (SIS)

Single image stereogram (SIS). SIS differs from earlier stereograms in its use of a single 2D image instead of a stereo pair and is viewed without a device. Thus, the term is often used as a synonym of autostereogram. When the single 2D image is viewed with proper eye convergence, it causes the brain to fuse different patterns perceived by the two eyes into a virtual 3D image without, hidden within the 2D image, the aid of any optical equipment. SIS images are created using a repeating pattern. Programs for their creation include Mathematica.

• Random dot autostereogram/hidden image stereogram

Is also known as single image random dot stereogram (SIRDS). This term also refers to autostereograms where the hidden 3D image is created using a random pattern of dots within one image, shaped by a depth map within a dedicated stereogram rendering program.

• Wallpaper autostereogram/object array stereogram/texture offset stereogram

Wallpaper autostereogram is a single 2D image where recognizable patterns are repeated at various intervals to raise or lower each pattern's perceived 3D location in relation to the display surface. Despite the repetition, these are a type of single image autostereogram.

• Single image random text stereogram (SIRTS)

An single image random text ASCII stereogram is an alternative to SIRDS using random ASCII text instead of dots to produce a 3D form of ASCII art.

• Map textured stereogram

In a map textured stereogram, "a fitted texture is mapped onto the depth image and repeated a number of times" resulting in a pattern where the resulting 3D image is often partially or fully visible before viewing.