Context Switching for Image Sensor Automatic Exposure Control

The patent implements dynamic switching between two operational contexts: a first context for fast AE control using short exposure times on low-resolution images, and a second context for accurate exposure measurement using long exposure times on high-resolution images. The system dynamically transitions between these contexts based on convergence criteria, allowing it to adapt its measurement strategy to current lighting conditions and converge to an accurate exposure value even under flickering artificial light.

The patent performs preliminary exposure estimation using the first context (short exposure, low-resolution) to quickly narrow down the exposure range. This preliminary action provides a rough exposure value that guides subsequent refined measurement in the second context, reducing the time required for accurate exposure determination while maintaining precision under flickering light conditions.

The system dynamically selects between two operational modes: using short exposure times when rapid response to light changes is needed (first context), and switching to long exposure times when accurate exposure measurement is the priority (second context). This dynamic adaptation allows the system to optimize between speed and accuracy based on real-time conditions and convergence progress.

The patent performs preliminary exposure estimation using short exposure times in the first context to quickly detect abrupt light changes and establish an initial exposure range. This preliminary action enables fast response to light changes while setting the stage for subsequent accurate measurement using long exposure times in the second context.

The patent segments the imaging process into two distinct functional streams: a low-resolution stream for rapid AE control and exposure estimation, and a high-resolution stream for final image output. The low-resolution images are used exclusively for exposure parameter determination, while high-resolution images are used for the final deliverable, allowing each stream to be optimized for its specific purpose without compromise.

The patent introduces an intermediary processing stage where low-resolution images serve as intermediate data for exposure estimation. These low-resolution images act as a mediator that enables fast AE control without directly affecting the quality of final high-resolution output images, as the exposure parameters derived from low-resolution images are applied to control the capture of high-resolution images.

The patent implements a dynamic context switching mechanism that adapts the AE control strategy based on convergence progress and lighting conditions. The system transitions between a first context (fast estimation mode) and a second context (refined measurement mode) using dynamically evaluated criteria, enabling adaptability to different illumination scenarios including flickering artificial light while managing complexity through structured state transitions.

The patent incorporates feedback mechanisms that monitor exposure convergence progress and lighting stability to determine when to switch between contexts. The feedback from exposure value analysis and brightness fluctuation detection triggers context transitions, allowing the system to adapt to different scenarios automatically while using structured feedback criteria to manage control complexity.