![random dot stereogram random dot stereogram](http://i.ytimg.com/vi/B_dvClRNcWI/maxresdefault.jpg)
Theseĭifferences allow the perception of depth.įigure 41-5 Viewing a Stereogram with Four Stripsįor an RDS, the eye crossing point must be farther in front of the image plane (that is, closer to the viewer) than in an SIS, so that the displacement of the images seen is the size of the image itself. Our eyes are separated from each other by about 65 mm, and this disparity causes slightly different images to be presented to the brain. Two similar photographs, but from different positions displaced horizontally (like our eyes).
![random dot stereogram random dot stereogram](http://s3-media1.fl.yelpcdn.com/bphoto/rv9d5322cP2lkws4mZWbAQ/ls.jpg)
The idea behind stereo photography is to take Stereo photography is very old, dating back to 1838, but some of the old stereo cameras and stereo photograph viewers, such as the one shown in Figure 41-1a, can still be found at antique shops. (representing the displacement between our eyes). Stereograms evolved from stereo photography, in which two photographs are taken from slightly different camera positions Vision-particularly depth perception and pattern recognition-created the random-dot stereogram (RDS). It all started back in the 1960s, when Bela Julesz, who worked at (AT&T) Bell Labs researching human 41.1 What Is a Stereogram?Ī stereogram is a 2D image that encodes stereo information so that, when viewed correctly, it reveals a hidden 3D scene. Asterisks show stimulus conditions where the accumulated number of correct responses exceeded the limit of chance level performance.Paralelo Computação Ltda. Horizontal red line at 32% correct responses indicates the limit of chance level performance when responses of all participants are accumulated. Horizontal gray line at 60% correct responses indicates the limit of chance level performance for individual participants. Gray traces show individual responses of the participants the red trace is the group average. We varied only the red component of each color for the red filter and only the green component of each color for the green filter. The left and right columns show results for the two sessions performed with participants viewing through the red (left) and green (right) filters, respectively. Each row represents one of the four anaglyphic colors. The abscissa shows the digital video values (at 8 bit resolution) with the vertical blue line indicating the values predicted by our model. Percent correct responses in a psychophysical task measuring the visibility of monocular artefacts in a DRDC. This approach is useful for designing psychophysical experiments using cyclopean stimuli for a specific display. Although we used a specific monitor and red-green glasses as an example, our method can be easily applied for other filter based three-dimensional systems. We also explored the error by which a range of luminance and contrast combinations can be implemented. We demonstrated in a psychophysical experiment with color normal participants that this solution is optimal because monocular cues were not detectable at either the calculated or the experimentally measured optima. We present an optimization algorithm that provides the set of digital video values that achieve minimal crosstalk at user-defined average luminance and dot contrast for both eyes based on photometric characteristics of a given display. Here, we use a simple mathematical model describing the relationship of digital video values and average luminance and dot contrast in the two eyes. Without proper calibration, this may result in unwanted monocular cues in DRDSs and DRDCs, which may bias scientific or diagnostic results. However, widely used filter-based three-dimensional display technologies often cannot guarantee complete separation of the images intended for the two eyes. Thus, they are important tools in assessing stereoscopic function in experimental or ophthalmological diagnostic settings. Dynamic random dot stereograms (DRDSs) and correlograms (DRDCs) are cyclopean stimuli containing binocular depth cues that are ideally, invisible by one eye alone.