Related Experiment Video
Updated: Jun 16, 2026

10:28
Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization
Published on: July 5, 2016
Lensless holographic recognition of spatially incoherent patterns in real time
Applied Optics
|January 30, 2010
Abstract:
Self-luminous patterns and patterns on diffusing backgrounds can be recognized in real time by means of multiple holographic filters in an approach that requires no imaging lenses. Use of filters matched to features rather than to entire characters has allowed reading of alphabetic characters printed on white paper at contrast ratios down to 1.7:1. The experimental geometry eliminates aberrations as a problem.
Related Concept Videos
Depth Perception and Spatial Vision
Depth perception is the ability to perceive objects three-dimensionally. It relies on two types of cues: binocular and monocular. Binocular cues depend on the combination of images from both eyes and how the eyes work together. Since the eyes are in slightly different positions, each eye captures a slightly different image. This disparity between images, known as binocular disparity, helps the brain interpret depth. When the brain compares these images, it determines the distance to an object.
Parallel Processing
The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and...

