Picture Conversion for Visual Consistency Across Display Luminances
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When displaying a picture created using a low-luminance display device on a high-luminance display device, the appearance of the picture differs significantly due to varying inter-adjacent gradation JND index differences, making it difficult to maintain intended visual appearances across different display luminances.
Innovation Solution
A method is implemented to convert the picture by setting gradation characteristics on the high-luminance display device to match the inter-adjacent gradation JND index differences of the low-luminance display device, using a correction factor to adjust luminance gradation values, ensuring the appearances of the picture are visually consistent across different luminance levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a picture is displayed on a high-luminance showing display device without conversion, then high viewability is obtained, but the appearance of the picture differs significantly from the intended appearance created on a low-luminance creation display device
Solution Approach 1:
The patent applies parameter changes by adjusting the gradation characteristics (gamma correction) of the picture data to compensate for the luminance difference between creation and showing display devices. By modifying the luminance gradation values according to the ratio of display luminances and inter-adjacent gradation JND index differences, the picture maintains its intended appearance when displayed at high luminance.
2Manufacturing precision
If the display luminances of creation and showing display devices are made the same, then appearance reproduction accuracy is improved, but the showing display device cannot exhibit its high display luminance capability and the creator cannot know the showing display device's luminance during creation
Solution Approach 1:
The patent applies preliminary action by pre-calculating and applying a conversion process to the picture data before display. The gradation characteristics are adjusted in advance based on the known luminance ratio between creation and showing devices, allowing the picture to be displayed at high luminance while maintaining appearance accuracy without requiring the devices to have the same luminance.
3Device complexity
If standard gamma correction is applied without considering inter-adjacent gradation JND index differences, then the conversion process is simple, but the appearance of low-gradation regions (mostly blackish areas) does not match the intended appearance
Solution Approach 1:
The patent applies local quality by differentiating the conversion approach for different gradation regions. Instead of uniform gamma correction, the conversion process specifically addresses low-gradation regions by using the inter-adjacent gradation JND index difference to determine appropriate luminance gradation values, ensuring that blackish areas and low-luminance regions maintain their intended appearance characteristics.
Data Source
AI summary
Provided is a picture conversion method capable of, when displaying a picture obtained from identical video data on a display device at different display luminances, converting the picture so that appearances of the picture visually come close to each other. The method includes a step of converting the picture by setting gradation characteristics when displaying the picture at a second luminance so that an inter-close gradation JND corresponding value difference at the second display luminance comes close to an inter-close gradation JND corresponding value difference at a first display luminance in a target gradation range which is at least part of an entire gradation range.