Beam Splitter Extended Dynamic Range Image Capture
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Solution Overview
Problem
Conventional image sensors have a limited dynamic range, leading to the 'throwing away' of image information in scenes with both bright and dim features, as they either capture highlights accurately but dim regions as 'black' or vice versa due to exposure conditions, resulting in incomplete image capture.
Innovation Solution
An optical system with beam splitters that separate incident light into portions with significantly different photon fluxes, allowing each image sensor to capture images under tailored exposure parameters, thereby capturing a high-dynamic range image by balancing exposure conditions for both bright and dim areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single image sensor is used with fixed exposure parameters, then the exposure is optimized for average scene brightness, but bright regions become overexposed and dim regions become underexposed, resulting in loss of image information
Solution Approach 1:
The patent divides the incident light into multiple portions with different photon flux levels using beam splitters. Each portion is directed to a separate image sensor, allowing each sensor to capture images optimized for specific brightness ranges. This segmentation resolves the contradiction by enabling simultaneous capture of both bright and dim region information without compromise.
2Illumination intensity
If exposure parameters are adjusted to capture dim regions accurately, then dim regions are properly exposed, but bright regions become overexposed and lose detail
Solution Approach 1:
The beam splitter system separates light into multiple intensity portions, directing attenuated light to one sensor and full-intensity light to another. This allows each sensor to be optimized for its specific brightness range, capturing both dim and bright region information simultaneously without the trade-off present in single-sensor systems.
Solution Approach 2:
Different image sensors are assigned different exposure parameters tailored to their specific light portions. Sensors receiving attenuated light use longer exposure times, while sensors receiving full-intensity light use shorter exposure times. This local optimization of exposure parameters resolves the contradiction by allowing each sensor to capture its designated brightness range accurately.
3Adaptability or versatility
If multiple images are captured at different exposure times to achieve high dynamic range, then extended dynamic range is obtained, but temporal mismatch and parallax errors occur between images
Solution Approach 1:
The patent merges multiple image captures into a single composite high dynamic range image by combining data from multiple sensors that captured images simultaneously. This simultaneous capture approach eliminates temporal mismatch between images, while the beam splitter optical path ensures all sensors view the same scene from the same perspective, eliminating parallax errors.
Solution Approach 2:
Multiple image sensors create simultaneous copies of the same scene under different exposure conditions. Each sensor captures a copy of the incident light portion directed to it, allowing the system to obtain multiple exposure-level images at the same moment in time, thus avoiding temporal artifacts while achieving extended dynamic range.
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 enables the capture of more faithful and complete images by combining images from sensors with different exposure times, eliminating temporal mismatch and parallax errors, resulting in extended dynamic range imaging that retains information from both bright and dim regions.
Implementation Method 1
one or more beam splitters configured to separate incident light into at least two portions
Data Source
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AI summary
An optical system and method may relate to capturing extended dynamic range images. In an example embodiment, the optical system may include a lens element configured to receive incident light and a beam splitter optically coupled to the lens element. The beam splitter is configured to separate the incident light into at least a first portion having a first photon flux and a second portion having a second photon flux. The first photon flux is at least an order of magnitude greater than the second photon flux. A controller may be configured to cause a first image sensor to capture a first image of the first portion of the incident light according to first exposure parameters and cause a second image sensor to capture a second image of the second portion of the incident light according to second exposure parameters.