Stereobilds

A stereobild is an image pair designed to create the perception of three-dimensional depth when viewed with the appropriate device or technique. It encodes two slightly different images for the left and right eye, reproducing binocular disparity that the brain combines into a single 3D scene.

Common formats include stereo pairs displayed side by side or one above the other, and anaglyphs that encode each image in a different color channel for viewing with colored glasses. Polarized and active shutter systems separate the left and right images using glasses in 3D cinema or displays, while free-viewing methods such as cross-eyed or parallel viewing let viewers fuse the pair without glasses.

Historically, stereobilds emerged from 19th-century experiments in binocular vision. Charles Wheatstone introduced the stereoscope in 1838, which allowed observers to fuse two photographs into a single 3D image. The concept spurred widespread popularization in the late 19th and early 20th centuries with viewers and stereo cards.

Production of stereobilds involves aligning two cameras to simulate interpupillary distance to control parallax, or synthesizing images digitally. Proper alignment and appropriate parallax are important, as misalignment or excessive parallax can cause eye strain or false depth perception.

Applications of stereobild technology span photography, film, medical imaging, architecture visualization, and virtual reality. In modern media, stereobilds appear in 3D movies, VR scenes, and 3D displays, with formats and display technologies varying among anaglyphs, polarization, and active shutter systems.

Viewer safety and accessibility considerations include potential discomfort from prolonged viewing or rapid parallax changes. Content creators are encouraged to balance depth and viewing distance to minimize strain.