Occlusion-Based Height Estimation Using Transmitter-Receiver Disparity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current projection and 3D measurement systems, such as those using infrared light planes and optical time-of-flight methods, struggle with accurately recognizing mid-air gestures and distinguishing between true contact and hovering due to limitations in resolution and sensitivity to anomalies in the projection surface.
Innovation Solution
The system employs occlusion-based height estimation by analyzing the size and position of occluded surface illumination areas, combining 2D planar image processing with z-axis triangulation using transmitter-receiver disparity, to determine the height of foreground objects above a background surface with high accuracy, even with erroneous illumination data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If infrared light plane is projected near the projection surface to detect objects, then object detection sensitivity is improved, but mid-air gestures above the plane cannot be recognized
Solution Approach 1:
The system transitions from 2D planar detection to 3D spatial detection by introducing transmitter-receiver disparity. The baseline distance between transmitter and receiver creates a stereo vision effect, enabling depth measurement and mid-air gesture recognition while maintaining surface contact detection capability.
2Length of stationary object
If optical time-of-flight measurement is used for medium-long range depth imaging, then range sensing capability is improved, but resolution at close distances deteriorates due to electronic circuitry limitations
Solution Approach 1:
The system applies different measurement approaches for different distance ranges. For close distances, it uses occlusion-based geometric calculation which provides high resolution. For medium-long ranges, it employs time-of-flight measurement. The system seamlessly combines these methods based on the local measurement requirements.
3Device complexity
If transmitter and receiver are co-located for simple system design, then device complexity is reduced, but occlusion-based height estimation capability is lost
Solution Approach 1:
The system uses the occluded region on the projection surface as an intermediary to indirectly measure the height of foreground objects. Instead of directly measuring object height, it measures the shadow cast on the surface and calculates height from this intermediate measurement, enabling height estimation without complex direct sensing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for precise differentiation between touch and hover events, improving gesture recognition and interaction accuracy by effectively handling errors in measured quantities and reflectance variations.
Implementation Method 1
a light transmitter (TX) and a light receiver (RX)... The TX/RX may be used to illuminate and detect a background surface within a field of view
Implementation Method 2
combining 2D planar image processing with z-axis triangulation using transmitter-receiver disparity
Data Source
AI summary
A projection system emits light pulses in a field of view and measures properties of reflections. Properties may include time of flight and return amplitude. Foreground objects and background surfaces are distinguished, distances between foreground objects and background surfaces are determined based on reflections that are occluded by the foreground objects and other properties of the projection system.