Mobile Terminal HDR Image Synthesis and Log Profile Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mobile terminals struggle to display high dynamic range (HDR) images effectively due to the loss of HDR information during tone mapping and challenges in adjusting camera exposure to capture HDR images, especially when the target light amount changes.
Innovation Solution
A mobile terminal with a camera and controller that synthesizes image data from multiple exposures, applies a log profile to store HDR information, and transforms it for display, while controlling exposures based on average and maximum brightness information to maintain HDR details.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If tone mapping process is applied to transform HDR image into SDR image for display on mobile terminal, then the image can be displayed on standard display, but HDR information is lost in the process
Solution Approach 1:
The patent extracts and preserves HDR information separately from the standard SDR display pipeline. By capturing images at multiple exposure levels and maintaining the original HDR data in a separate buffer, the system can display SDR images on standard displays while preserving HDR information for later use or alternative display methods.
Solution Approach 2:
The patent implements a nested structure where SDR display output is embedded within a larger HDR information container. The processed SDR image for display is nested within the preserved multi-exposure HDR data, allowing the system to provide both standard display output and retained HDR information simultaneously.
2Extent of automation
If camera exposure is adjusted by comparing target light amount with current light amount, then exposure control can be implemented, but it becomes impossible to reach target light amount when target light amount changes
Solution Approach 1:
The patent performs preliminary capture of multiple exposure levels simultaneously or in rapid succession before the scene lighting conditions can change. By capturing under-exposed, properly exposed, and over-exposed images in a single processing sequence, the system ensures that at least one image will have the correct exposure regardless of lighting variations during the capture sequence.
Solution Approach 2:
The patent changes the exposure parameter (light amount) across multiple captured images rather than attempting to perfectly control a single exposure. By capturing images at different exposure levels (under-exposed, properly exposed, over-exposed), the system transforms the problem from achieving perfect single-exposure accuracy to selecting the best result from multiple parameter variations.
Data Source
AI summary
A mobile terminal including a camera having an image sensor; a memory; a display; and a controller configured to synthesize first image data generated by a first exposure and second image data generated by a second exposure, store a log image in the memory obtained by applying a log profile to the synthesized image data in a first mode, and display a first image on the display obtained by transforming the log image in a second mode. Further, the controller controls the first exposure and the second exposure based on first exposure information corresponding to an average brightness information and a maximum brightness information of the synthesized image data.