Image Dynamic Range Mapping with Histogram-Guided Cubic Splines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image processing methods fail to effectively adjust the dynamic range of images to adapt to different display devices, resulting in loss of luminance levels and poor display effects due to inflexible mapping curves.
Innovation Solution
The method employs cubic spline curves to map luminance values of pixels based on histogram information, allowing for flexible adjustment of the dynamic range by determining interpolation points and modifying the mapping relationship of pixels, thereby enhancing the display effect on various display devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional mapping curve is used to adjust dynamic range, then the mapping process is simple, but luminance levels are lost and luminance contrast is not obvious
Solution Approach 1:
The mapping curve is divided into multiple segments, with different cubic spline curves applied to different luminance intervals. This segmentation allows each interval to be optimized independently for preserving luminance levels while maintaining overall mapping simplicity.
Solution Approach 2:
The patent uses dynamic range adjustment by adaptively determining interpolation points based on histogram information. The mapping curve dynamically adapts to the specific image content through histogram-based analysis, improving luminance contrast preservation while maintaining operational simplicity.
2Ease of manufacture
If a fixed mapping curve is used, then the implementation is straightforward, but the display effect on different display devices is poor
Solution Approach 1:
The patent changes the parameters of the mapping curve by determining interpolation points based on histogram information of the image. This allows the mapping curve to adapt to different display devices and image characteristics while maintaining a straightforward implementation through automated parameter adjustment.
Solution Approach 2:
The cubic spline curve-based mapping method serves multiple functions: it works for different display devices with varying dynamic ranges, handles different image types through histogram analysis, and maintains implementation simplicity. This universal approach replaces the need for device-specific fixed mapping curves.
3Productivity
If a simple mapping curve is used, then the processing speed is fast, but luminance contrast is not obvious
Solution Approach 1:
The patent performs preliminary histogram analysis on the image before generating the mapping curve. This preliminary action extracts luminance distribution characteristics that guide the creation of an optimized cubic spline curve, improving luminance contrast without significantly impacting processing speed due to the efficiency of histogram-based analysis.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
This application provides an image dynamic range processing method and apparatus. The method includes: obtaining a first coordinate value of a first interpolation point and a first coordinate value of a third interpolation point related to a first cubic spline curve; and determining, based on histogram information of a first luminance interval of a to-be-processed image, a first coordinate value of a second interpolation point related to the first cubic spline curve. The first luminance interval is an interval between the first coordinate value of the first interpolation point and the first coordinate value of the third interpolation point. The first coordinate value of the first interpolation point, the first coordinate value of the second interpolation point, and the first coordinate value of the third interpolation point are used to determine a function of the first cubic spline curve. The function of the first cubic spline curve is used to map a luminance value of a pixel whose luminance value is in the first luminance interval in the to-be-processed image to a first target luminance value, to modify a dynamic range of the to-be-processed image. This application improves image display effect.