Projector Orientation Sensing for Faster Keystone Correction
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Solution Overview
Problem
Existing projection technologies require a long period to complete geometric correction due to the delay in initiating measurements necessary for trapezoidal distortion correction until a stationary state is detected.
Innovation Solution
A method and apparatus that utilize sensors to determine movement cessation, detect depth maps, and correct image distortion based on orientation relative to the projection surface, enabling immediate initiation of geometric correction upon stabilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If geometric correction is initiated only after detecting that the projector has stopped moving, then the correction accuracy is ensured, but the time required to complete the geometric correction increases
Solution Approach 1:
The system initiates depth map measurement before the projector movement stops. By starting the measurement process in advance and continuing it through the stopping period, the system ensures that measurement data is collected without waiting for the movement to completely cease, thereby reducing the overall correction time while maintaining accuracy.
2Loss of time
If depth map measurement is performed during the projector movement, then the measurement time is reduced, but the measurement accuracy deteriorates due to movement
Solution Approach 1:
The depth map measurement is started before the projector stops moving and continues during the stopping period. This preliminary action ensures that the measurement process is already underway when the projector stabilizes, allowing data collection to occur during the stationary period without extending the total measurement time.
Solution Approach 2:
The measurement process continues uninterrupted from the moving state through the stopping state. By maintaining continuous measurement operation rather than pausing or restarting, the system efficiently utilizes the stopping period for accurate data collection without adding extra time overhead.
Data Source
AI summary
A method for controlling a projection apparatus configured to project an image onto a projection receiving surface, a first period containing a second period, the method including: determining based on an output from a first sensor that a movement of the projection apparatus stops when a state in which a parameter value indicating the movement is smaller than a first threshold continues for the first period; detecting at least one depth map indicating a distance from a second sensor to each of multiple positions on the projection receiving surface based on an output from the second sensor in at least a portion of the first period; identifying an orientation of the projection apparatus with respect to the projection receiving surface based on the at least one depth map; and correcting distortion of the image based on the orientation when it is determined that the movement stops.