This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 111122663 filed in Taiwan, R.O.C. on Jun. 17, 2022, the entire contents of which are hereby incorporated by reference.
The present disclosure relates to the field of a gamma correction system of display device, and more particularly relates to an automatic gamma adjustment system with environmental adaptability.
When projecting digital images through a display screen, if the image is displayed on a panel without gamma correction, the viewer will often feel that the image is white, too-bright, or too-dark, and this is due to the photosensitive function of the display device. The brightness intensity of the pixel is not linearly related to the input voltage intensity, and the way for human eyes to capture the brightness is also not proportional. It is the case under non-extremely dark or non-extremely bright conditions, and the normal vision of the human eyes is more sensitive to the change in dark tones and other factors. For this reason, in addition to the adjustment of the image color effect by adjusting the brightness of backlight or the driving current of the panel, all kinds of display devices on the market are actively improving the accuracy of gamma correction, in order to achieve the effect of accurately adjusting the balance of color grayscale in pixel values to correct the overall visual brightness effect of the image.
However, when a traditional display device adjusts the gamma value, it is often performed by the driver IC at the end of the overall device circuit, and this structure increases the complexity of the circuit design of the driver IC. Especially for a display device that uses a plurality of small and medium-sized panels to form a large screen, the design complexity will be increased significantly because the driver ICs on each of the small and medium-sized panels need the setting of synchronous or serial signals. Furthermore, if the image input signal received by the display screen is an RGB signal, the setting value must be changed for each RGB signal source, which further increases the complexity of software design, and such traditional display device is not conducive to the economic benefits of industrial development. In view of this problem, it is the subject for the present disclosure to find a feasible solution to use the YCbCr conversion technology to convert any image input signal into YUV signal, while calculating or looking up the optimal gamma value according to the surrounding environmental parameter of the real-time device, so as to improve the aforementioned drawback of the prior art, optimize the balance of image color grayscale, and achieve the most comfortable image display effect for human eyes.
Therefore, it is a primary objective of the present disclosure to provide an automatic gamma adjustment system that can achieve the effect of optimizing the overall image quality according to environmental conditions by optimizing the driving current of the display screen and the grayscale value of the image color through environmental parameters.
To achieve the aforementioned and other objectives, this disclosure discloses an automatic gamma adjustment system with environmental adaptability, installed in a display device, and provided for automatically correcting a gamma value at any time according to the surrounding situation to adjust the grayscale layering presented to people. This disclosure is characterized in that the automatic gamma adjustment system with environmental adaptability includes a signal receiving processor, a situation capture processor and a layering control processor, and the signal receiving processor selects an image signal source and receives and converts an image signal into a plurality of first YUV signals; the situation capture processor detects the surrounding situation to capture and obtain at least one environmental data, and obtains a gamma control parameter of a display screen of the display device according to the calculation of the environmental data; and the layering control processor calculates the environmental data to obtain a maximum brightness current value, while using the gamma control parameter to calculate the first YUV signals as a plurality of second YUV signals, and sends the maximum brightness current value and the second YUV signals to the display device, which are provided for the display screen to display the image according to the maximum brightness current value and the second YUV signals.
Wherein, the environmental data include air quality, weather condition, and ambient brightness. The display device uses an 8-bit, 13-bit, 16-bit or 24-bit grayscale image to display the image, and when the grayscale level is greater than 256 levels, and the layering control processor uses the gamma control parameter to calculate and obtain the second YUV signals, an adaptive offset compensation is used to adjust the brightness values of the 0˜8th grayscale layers, such that the brightness values of the 0˜8th grayscale layers do not have consecutive zero outputs; after the adaptive offset compensation counts the total number of levels with a brightness value equal to 0 in the 1st˜8th grayscale layers, reads the minimum brightness value in the 1st˜8th grayscale layers, and lists the missing decimal integers and the quantity of missing decimal integers within a non-consecutive numbers range of the 1st˜8th grayscale layers, the minimum brightness value is filled into the first grayscale layer, and then the decimal-integers are used sequentially to linearly adjust the brightness value of at least some of the 0˜8th grayscale layers. The display device uses an 8-bit, 13-bit, 16-bit or 24-bit grayscale image to display the image, and when the grayscale level is greater than 256 levels, the layering control processor calculates and obtains the second YUV signals by the gamma control parameter, an adaptive adjustment is used to adjust the brightness values of the 0˜8th grayscale layers, such that the brightness values of the 0˜8th grayscale layers do not have four or more consecutive zero outputs of the brightness values.
In addition, the display screen is formed by a plurality of display panels, and the display device makes one of the display panels as a commander and the rest of the display panels as followers, and after the display panel acting as the commander receives the second YUV signals and the maximum brightness current value transmitted by the layering control processor to drive the display panels acting as the remaining followers to use the second YUV signals and the maximum brightness current value to display the image, such that the image displayed by the display screen shows a unified grayscale layering. The layering control processor includes a memory storage unit, provided for the layering control processor to use the gamma control parameter to calculate and obtain the second YUV signals and buffer the second YUV signals into the memory storage unit, or use the gamma control parameter to look up in a table to obtain the second YUV signals stored in the memory storage unit; wherein the memories of the memory storage unit and the display device have a first gamma parameter conversion table and a second gamma parameter conversion table respectively, provided for the layering control processor to look up the second YUV signals from the first gamma parameter conversion table and the second gamma parameter conversion table, such that the memory storage unit can still provide multi-selective gamma groups in the case of low memory storage capacity; the layering control processor includes a temperature protection unit and a maximum brightness conversion unit, the temperature protection unit is electrically connected to the display screen for receiving a current working temperature fed back by the display screen, and driving the maximum brightness conversion unit to adjust the maximum brightness current value if the obtained current working temperature is determined to be not falling within a safe interval value; and the layering control processor further converts the second YUV signals into a plurality of RGB signals.
After the signal receiving processor analyses the image signal to obtain a corresponding image grayscale distribution data, and the layering control processor analyses the image grayscale distribution to highlight a range with concentrated image grayscale distribution, the image signal in the range is used to calculate the gamma control parameter to obtain the second YUV signals corresponding to a full grayscale level, so as to improve the fineness of the grayscale presented in the range, so that the overall too-dark or too-bright image can be presented with rich detailed image to satisfy the visual experience of human eyes.
In summation of the description above, the present disclosure uses the layering control processor to pre-process the image signal and directly provide the second YUV signals with maximum current parameter after white balance and optimal eye comfort to the display device, such that the display screen can directly use the received parameters or data for the display of the image without the need of calculating each of the R, G, B signals, so as to reduce the software design complexity and hardware specification requirements of the IC in the display device. In order to provide the second YUV signals with optimal eye comfort, the present discloser uses the environmental data captured by the situation capture processor to calculate and obtain the gamma control parameter.
Based on the real surrounding environment, the most suitable gamma value for human eyes is selected, so that even the image of a crow flying in the dark night can still be clearly presented to the viewer without any deviation, that is, to achieve the optimal display quality and the perfect visual comfort for human eye.
This disclosure will now be described in more detail with reference to the accompanying drawings that show various embodiments of this disclosure.
With reference to
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In addition, the layering control processor 12 can convert the second YUV signals 1200 into a plurality of RGB signals and then send the RGB signals and the maximum brightness current value 1220 altogether to the display screen 20.
Wherein, the components of the present disclosure are realized through hardware, or software supplemented by hardware, for example, the definitions of the signal receiving processor 10, the situation capture processor 11 and the layering control processor 12 essentially refer to the integration of various hardware devices such as CPU, microprocessor, memory or signal transmitter, etc., and are implemented with software programs. Of course, the present disclosure can be provided with a GUI interface for the viewers to adjust the gamma value or brightness, or switch to the black screen mode for sleep, etc., and the memory storage unit 121 can be integrated into a FPGA circuit board, so that the second YUV signals 1200 and the maximum brightness current value 1220 outputted through the FPGA circuit integration can be exported to the driver IC of the display screen 20 by the system of the present disclosure.
Number | Date | Country | Kind |
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111122663 | Jun 2022 | TW | national |
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20230410712 A1 | Dec 2023 | US |