Gamma Correction for Multi-Projector Luminance Uniformity
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Solution Overview
Problem
In multi-projection systems, seamlessly connecting the luminance of images from multiple projectors in their superimposed areas is challenging due to individual differences in projectors, particularly when the camera-generated image data does not have a linear gamma characteristic, leading to potential luminance discrepancies.
Innovation Solution
A projection control apparatus that includes a corrector to adjust the imaging characteristic of captured image data using pixel values from a predetermined area, allowing for precise control of projectors to achieve smooth luminance connection through gamma correction, ensuring that the luminance of superimposed areas is uniformly displayed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If edge blending is performed to superimpose projection images from multiple projectors, then the connection between projection images is improved, but luminance differences appear in the superimposed area due to individual differences among projectors and nonlinear gamma characteristics
Solution Approach 1:
The patent applies gamma correction to transform the nonlinear gamma characteristics of the camera into linear characteristics. By changing the parameter representation of image data from nonlinear gamma to linear gamma, the system enables accurate luminance measurement and control in the superimposed area, thereby resolving the luminance difference issue while maintaining uniformity
Solution Approach 2:
The system uses the camera to capture the actual projection images and measures the luminance in the superimposed area. This captured information is fed back to the control apparatus, which then adjusts the projection images to compensate for luminance differences. This closed-loop feedback mechanism ensures both uniformity and proper luminance balance
2Ease of operation
If automatic adjustment is performed without gamma correction, then the adjustment process is simplified, but the superimposed area exhibits slight luminance differences due to nonlinear gamma characteristics
Solution Approach 1:
The patent performs gamma correction as a preliminary processing step before the automatic luminance adjustment. By pre-transforming the camera's nonlinear gamma characteristics into linear characteristics, the system prepares the image data in a form that enables accurate luminance measurement and control, ensuring both ease of automatic operation and luminance uniformity
Data Source
AI summary
A projection control apparatus is configured to control a first image projection apparatus that projects a first image and a second image projection apparatus that projects a second image so that the first image and the second image are superimposed on each other in a predetermined area. The projection control apparatus includes a corrector configured to correct an imaging characteristic for converting a received light amount into captured image data in an imaging apparatus configured to capture the first and second images, by using a pixel value of the predetermined area in the captured image data obtained from the imaging apparatus, and a controller configured to control at least one of the first and second image projection apparatuses using a corrected imaging characteristic.