An autostereogram is a type of image that appears to be a flat 2D image when viewed normally, but when viewed with a special technique, it appears to be a 3D image with depth and perspective.
Autostereograms are created by repeating a pattern of repeating elements, such as random dots, in such a way that the repeating elements at different depths in the image align with each other when viewed with the special technique. This creates the illusion of a 3D image.
The image below appears as a 2 dimensional flat image, but when viewed using one of the techniques mentioned below, a 3 dimensional shape appears.
Table of Contents
- How does an Autostereogram work?
- Versions of Autostereograms
- Illusions like the Autostereograms
- Discovery of the Autostereograms
- References and Resources
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How does an Autostereogram work?
Autostereograms specifically are an example of a stereoscopic illusion, which is a type of optical illusion that creates the perception of depth and three dimensions in an image that is actually flat.
They are also known as “single image random dot stereograms (SIRDS)”.
To better see the 3D image in an autostereogram, there are a few techniques that can be used:
Wall-eyed or cross-eyed viewing: This technique involves diverging your eyes outward so that the left eye is focused on the right side of the image and the right eye is focused on the left side of the image. This can take some practice to get used to, but it is the most common way to view autostereograms.
Parallel viewing: Instead of crossing or diverging your eyes, you can also try to focus your eyes on a distant point in the room, while keeping them parallel to the image.
Focusing on a specific point: Some autostereograms have a “sweet spot” or a small dot or line that indicates where to focus your eyes. By focusing on that point, it may be easier to see the 3D image.
Viewing distance: The optimal viewing distance varies from person to person, but generally, the farther away from the image, the easier it is to see the 3D image.
Relaxation: It’s important to be relaxed while trying to see the 3D image, as tension in your eyes and face can make it harder to see the image.
It’s important to note that not everyone can see the 3D image in an autostereogram, and that’s normal. It depends on the individual’s visual perception and the structure of the image.
Versions of Autostereograms
The following are some alternate Autostereograms:
Illusions like Autostereograms
Autostereograms specifically are an example of a stereoscopic illusion, which is a type of optical illusion that creates the perception of depth and three dimensions in an image that is actually flat. They are also known as “single image random dot stereograms (SIRDS)”.
Some related illusions are below:
The rotating snakes is a peripheral drift illusion that consists of a grid of shapes, with some of them appearing to be rotating or undulating. The illusion is created by the interaction of the shapes with the neural processing of the visual system.
The Moiré pattern illusion: This illusion is created by superimposing two similar patterns on top of each other, such as a grid of lines or circles. The resulting pattern appears to be moving or changing.
The Scintillating Grid Illusion, in which a grid of black and white squares appears to pulsate or “breathe” when viewed from the periphery of the image.
The Hermann Grid Illusion in which the intersections of a white grid on a black background appear to be gray, even though they are actually the same color as the background.
The Zöllner Illusion, in which parallel lines appear to be tilted or bent when intersected by diagonal lines.
The barber pole illusion is an optical illusion that is characterized by the appearance of a spiral pattern on a vertically striped pole.
The Bezold Effect: This illusion is created by placing two or more colors next to each other, and the way they appear to change when they are close to one another.
The Café Wall Illusion is a visual illusion that is created by a grid of alternating light and dark horizontal and vertical lines. The lines appear to be bent or tilted, even though they are actually straight.
Discovery of Autostereograms
The invention of the autostereogram is credited to Dr. Bela Julesz, a Hungarian-born cognitive scientist and psychologist.
He first described the concept in his 1981 paper “Stereograms and the Brain” and later published a book “Textons, the elements of texture perception” which explained the theory behind autostereograms in detail.
He called them Random-Dot Stereograms (RDS) and was awarded a Turing award in 1995 for his contributions in this field of visual perception.
He also developed a computer program that could generate autostereograms, which allowed for the creation of more complex and realistic 3D images.
The term “Autostereogram” is derived from his original term “Random-Dot Stereograms (RDS)”.
References and Resources
Check out our complete list of illusions.