Global dimming method of liquid crystal display backlight based on image classification

A global dimming, liquid crystal display technology, applied in static indicators, instruments, etc., can solve the problems of low contrast, limited application of dynamic dimming technology, and high power consumption

Active Publication Date: 2013-05-15
HEFEI UNIV OF TECH
View PDF7 Cites 29 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Liquid crystal display has two inherent disadvantages: (1) low contrast; (2) high power consumption
[0003] Among the existing dimming algorithms, there are the invention patent "LED backlight overall dimming method and its device" proposed by Fuzhou University (application number: 200910309165.6), and the invention patent "side light" proposed by Guangzhou Skyworth Flat Display Technology Co., Ltd. Type LED backlight dynamic partition control method" (application number: 201010510536.X), the invention patent authorized by Qingdao Hisense Electric Co., Ltd. "LCD contrast adjustment method and device" (application number: 200710111510.6), before the applicant The inventio

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Global dimming method of liquid crystal display backlight based on image classification
  • Global dimming method of liquid crystal display backlight based on image classification
  • Global dimming method of liquid crystal display backlight based on image classification

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] Embodiment 1 divides images into 6 categories, namely, high brightness and high contrast, medium brightness and high contrast, low brightness and high contrast, high brightness and low contrast, medium brightness and low contrast, and low brightness and low contrast. The video source input is a standard definition image of 1024×768. Please refer to the specific dimming steps Figure 5 (d):

[0047] 1. Determine the number and threshold of image classification:

[0048] (1.1) Determine the number of image categories according to design requirements and hardware resources: Embodiment 1 divides images into 6 categories, namely, high brightness and high contrast, medium brightness and high contrast, low brightness and high contrast, high brightness and low contrast, medium brightness and low contrast, Low brightness and low contrast;

[0049] (1.2) Organize 6 natural persons with normal vision to watch 100 images with different contents, including day or night characters...

Embodiment 2

[0099] Embodiment 2 divides images into 6 categories, namely, high brightness and high contrast, medium brightness and high contrast, low brightness and high contrast, high brightness and low contrast, medium brightness and low contrast, and low brightness and low contrast. The classification thresholds of the six types of images have been obtained in Embodiment 1 and can be used repeatedly in Embodiment 2. The video source input is a high-definition image of 1920×1080. For the specific dimming steps of Embodiment 2, please refer to Figure 6 (c):

[0100] 1. Determine the number and threshold of image classification:

[0101] According to the design requirements and hardware resources, the image category is divided into 6 categories, namely, high brightness and high contrast, medium brightness and high contrast, low brightness and high contrast, high brightness and low contrast, medium brightness and low contrast, and low brightness and low contrast. In Embodiment 1, class...

Embodiment 3

[0136] Embodiment 3 divides images into 9 categories, namely high brightness and high contrast, medium brightness and high contrast, low brightness and high contrast, high brightness and medium contrast, medium brightness and medium contrast, low brightness and medium contrast, high brightness and low contrast, medium brightness and low contrast , Low brightness and low contrast. The video source input is a standard definition image of 1024×768. Please refer to the specific dimming steps Figure 7 (c):

[0137] 1. Determine the number and threshold of image classification:

[0138] (1.1) Determine the number of image categories according to design requirements and hardware resources: Embodiment 3 divides images into 9 categories, namely, high brightness and high contrast, medium brightness and high contrast, low brightness and high contrast, high brightness and medium contrast, medium brightness and medium contrast, Low brightness and medium contrast, high brightness and lo...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a global dimming method of liquid crystal display backlight based on image classification. The method includes the following steps: 1, determining how many types of images and classification thresholds, 2, computing brightness average value and contrast of all pixels of the input image, 3, classifying the images according to the classification thresholds, the brightness average value and the contrast, 4, determining parameter k in a backlight brightness computational formula according to the image category and computing a backlight dimming factor, 5, determining parameter a in a S-shaped curvilinear equation according to the image category, 6, computing brightness of an inflectional point on the S-shaped curve and obtaining corrected brightness of the inflectional point, 7, generating a S-shaped curve, 8, generating a light-emitting diode (LED) pulse width modulation signal according to the backlight dimming factor and changing the luminance of the LED light source plate completely, 9, adjusting brightness of each pixel according to the S-shaped curve so that the liquid crystal display displays the adjusted image according to the S-shaped curve. According to the global dimming method, computing parameter is selected according to the input image, and therefore, optimum effects of high contrast and low consumption of all images by means of dimming algorithm are guaranteed.

Description

technical field [0001] The invention belongs to the technical field of liquid crystal display, and in particular relates to backlight dynamic dimming technology. Background technique [0002] Liquid crystal displays have two inherent disadvantages: (1) low contrast; (2) high power consumption. At present, many researchers use backlight dynamic dimming technology to improve the contrast of liquid crystal display and reduce energy consumption at the same time. According to the backlight brightness adjustment method, the dynamic dimming technology can be divided into global dimming and local dimming. Global dimming is to change the brightness of the backlight as a whole, and local dimming is to divide the backlight into several areas that can be individually controlled, and determine the backlight brightness of this area according to the characteristic value of the image corresponding to the area. Compared with regional dimming, global dimming does not require partition desig...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G09G3/34G09G3/36
Inventor 吕国强冯奇斌
Owner HEFEI UNIV OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap