HDR Pixel Stream Generation via Multi-Exposure Blending
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Solution Overview
Problem
Traditional digital photography systems are limited by the dynamic range of image sensors, which restricts the capture of detailed images in high-contrast scenes, leading to loss of information in bright and dark areas.
Innovation Solution
A system and method for generating high dynamic range (HDR) images by receiving a pixel stream with multiple exposures per pixel from an image sensor, blending these exposures to create a HDR pixel stream, and outputting it for enhanced image detail in digital photographic systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If traditional single exposure capture is used, then the system is simple and fast, but the dynamic range is limited and details in bright/dark areas are lost
Solution Approach 1:
The patent segments the image capture process into multiple exposures with different metering values. Instead of capturing a single exposure, the system divides the capture into multiple frames (e.g., 3-5 exposures) with varying exposure levels, allowing different parts of the dynamic range to be captured separately and then combined to preserve detail information across the full dynamic range.
Solution Approach 2:
The patent adds the temporal dimension to the capture process by taking multiple exposures over time. By stacking multiple exposures in the time domain and combining them, the system expands the effective dynamic range beyond what a single spatial exposure can capture, effectively using time as an additional dimension to overcome the sensor's dynamic range limitation.
2Loss of information
If multiple exposures are captured and merged, then the dynamic range is expanded, but the processing time and complexity increase
Solution Approach 1:
The patent performs preliminary actions by capturing multiple exposures in rapid succession with pre-determined metering values before the scene changes significantly. The exposures are metered differently in advance, and the system is prepared to combine them using pre-calculated weighting factors, reducing the processing time required after capture.
Solution Approach 2:
The patent changes the exposure parameters (metering values, exposure times) across multiple captures to optimize the dynamic range coverage. By varying these parameters systematically and using adaptive weighting based on scene analysis, the system efficiently combines the exposures to maximize detail retention while minimizing processing overhead through algorithmic optimizations.
3Illumination intensity
If multiple exposures per pixel are captured, then the dynamic range is expanded, but the data volume and processing complexity increase
Solution Approach 1:
The patent applies partial action by selectively combining multiple exposures rather than processing all possible exposure combinations. It uses adaptive weighting to determine which exposures contribute most to each pixel's final value, processing only the necessary subset of exposure data needed to achieve the HDR result, thus reducing overall processing complexity while maintaining dynamic range expansion.
Solution Approach 2:
The patent creates simplified copies or representations of the multiple exposure data through intermediate processing steps. It generates weighted composite images from the multiple exposures, creating intermediate representations that are easier to process than the raw multi-exposure data, thereby reducing the computational complexity of the final HDR image generation while preserving the expanded dynamic range information.
Data Source
AI summary
A system, method, and computer program product are provided for performing high dynamic range mixing on a pixel stream. In use, the system receives a pixel stream including at least two exposures per pixel from a plurality of pixels of an image sensor. The system then generates a high dynamic range (HDR) pixel stream by performing HDR mixing on the received pixel stream. Finally, the system outputs the HDR pixel stream. Additional systems, methods, and computer program products are also presented.