Holograms provide a unique 3D representation by offering shifting perspectives based on the viewer's position and allowing the eye to adjust focal depth between the foreground and background. Unlike traditional lens-based photographs, which only encode the brightness of light waves, holograms encode both brightness and phase, delivering a more accurate depiction of parallax and depth. Building on this principle, our research presents a 3D holographic projection system utilizing the Pepper's Ghost technique, which creates illusionary 3D images through the reflection of light on a semi-reflective surface. The system is managed by a Raspberry Pi controller, enabling user interaction with the holographic content through hand gestures. To optimize the display, precisely angled acrylic sheets are employed to project 3D images effectively. Further enhancing the 3D viewing experience, we convert 2D videos to 3D by segmenting foreground objects from the background, contributing to a more immersive experience. Central to this study is the investigation of the optimal angle for achieving the best illusion, using Fresnel equations for electromagnetic waves. The findings identify an optimal reflective angle of 50.65° with a transparent acrylic sheet having a refractive index of 1.4899. This ensures the highest quality Pepper's Ghost effect, significantly enhancing the overall holographic display and bringing the 3D holographic projection system to its full potential.
The holographic setup utilizes the Pepper's Ghost illusion, aligning the angle of incidence with the acrylic sheet to create a virtual image that mirrors the actual object in both distance and orientation, providing an immersive experience for observers.
This video features interactive 3D objects controlled by Leap Motion and haptics, integrated into our system. The 3D objects are spawned with a pinching gesture and can be picked up and colored using both Leap Motion and haptics.