The disclosure generally relates to a driving controller. More particularly, the disclosure relates to a method for outputting a grayscale data, a driving controller, and a display apparatus.
Traditionally, in order to increase the continuity of the gradient zone of the LED display, the color depth would be increased to eliminate the contour phenomenon. Since increasing the color depth requires higher costs, a dither computing is usually adopted. The dither computing adds various dithering values to grayscale data to make grayscale data changes smoothly, thereby visually equivalently increasing the color depth to compensate for the contour phenomenon.
However, the dither computing results in a flicker phenomenon. The dither computing includes truncating lower bit(s) of original grayscale data that is with the expected bit depth and adding dithering value(s) to the truncated grayscale data, so as to generate a plurality of dithered grayscale data to be displayed according to a given time sequence. Please referring to
The disclosure is directed to a method for outputting a grayscale data, a driving controller, and a display apparatus, by which the flicker phenomenon can be reduced while the dithering operation is applied.
In an embodiment of the disclosure, a method for outputting a grayscale data in a driving controller of a display apparatus is provided. The method includes: in response to receiving a first input grayscale data which is not greater than a first threshold, generating a first output grayscale data without performing a dither computing on the first input grayscale data and outputting the first output grayscale data; and in response to receiving a second input grayscale data which is greater than a second threshold, generating a first dithered grayscale data by performing a first dither computing on the second input grayscale data and outputting the first dithered grayscale data as a second output grayscale data. The second threshold is greater than the first threshold, and the second output grayscale data does not comprise any part of the second input grayscale data not processed by the first dither computing.
In an embodiment of the disclosure, a driving controller of a display apparatus is provided. The driving controller includes an image processing circuit. In response to that the image processing circuit receives a first input grayscale data which is not greater than a first threshold, the image processing circuit is configured to generate a first output grayscale data without performing a dither computing on the first input grayscale data and configured to output the first output grayscale data. In response to that the image processing circuit receives a second input grayscale data which is greater than a second threshold, and the second threshold is greater than the first threshold, the image processing circuit is configured to generate a first dithered grayscale data by performing a first dither computing on the second input grayscale data and configured to output the first dithered grayscale data as a second output grayscale data. The second output grayscale data does not comprise any part of the second input grayscale data not processed by the first dither computing.
In an embodiment of the disclosure, a display apparatus is provided. The display apparatus includes a pixel array, a data driving circuit, and a driving controller. The data driving circuit is coupled to the pixel array, and the data driving circuit is configured to provide driving signals to drive the pixel array. The driving controller is coupled to the data driving circuit, and the driving controller includes an image processing circuit. In response to that the image processing circuit receives a first input grayscale data which is not greater than a first threshold, the image processing circuit is configured to generate a first output grayscale data without performing a dither computing on the first input grayscale data and configured to output the first output grayscale data. In response to that the image processing circuit receives a second input grayscale data which is greater than a second threshold, and the second threshold is greater than the first threshold, the image processing circuit is configured to generate a first dithered grayscale data by performing a first dither computing on the second input grayscale data and configured to output the first dithered grayscale data as a second output grayscale data. The second output grayscale data does not comprise any part of the second input grayscale data not processed by the first dither computing.
In an embodiment of the disclosure, a display apparatus is provided. The display apparatus includes a pixel array, a driving controller, and a data driving circuit. The driving controller is configured to perform an image processing on a first input grayscale data and a second input grayscale data. The data driving circuit is coupled to the driving controller and the pixel array. The data driving circuit is configured to provide driving signals to drive the pixel array based on a grayscale data output from the driving controller. In response to the first input grayscale data which is not greater than a first threshold, the data driving circuit is configured to output a first driving signal to the pixel array based on a first output grayscale data output from the driving controller. The first output grayscale data is generated without by performing a dither computing on the first input grayscale data. In response to the second input grayscale data which is greater than a second threshold, the data driving circuit is configured to output a second driving signal to the pixel array based on a second output grayscale data output from the driving controller. The second output grayscale data is a dithered grayscale data generated by performing a dither computing on the second input grayscale data.
To make the aforementioned more comprehensible, several embodiments accompanied with drawings are described in detail as follows.
The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.
Embodiments are provided below to describe the disclosure in detail, though the disclosure is not limited to the provided embodiments, and the provided embodiments can be suitably combined. The term “coupling/coupled” or “connecting/connected” used in this specification (including claims) of the application may refer to any direct or indirect connection means. For example, “a first device is coupled to a second device” should be interpreted as “the first device is directly connected to the second device” or “the first device is indirectly connected to the second device through other devices or connection means.” The term “signal” can refer to a current, a voltage, a charge, a temperature, data, electromagnetic wave or any one or multiple signals. In addition, the term “and/or” can refer to “at least one of”. For example, “a first signal and/or a second signal” should be interpreted as “at least one of the first signal and the second signal”.
In the present embodiment, the image processing circuit 100 may be an electronic device having an image processing function. In an embodiment, the image processing circuit 100 may be, but not limited to, a central processing unit (CPU) or a programmable microprocessor, a digital signal processor (DSP), a programmable controller, an application specific integrated circuit (ASIC) or other similar devices or a combination of above-mentioned devices disposed in a driving controller of a light emitting diode (LED) display. The image processing circuit 100 receives input grayscale data IN of an image and performs the image processing function on the input grayscale data IN to generate output grayscale data OUT for improving the continuity of the gradient zone of the image through a digital signal processing. Each of the input grayscale data IN and the output grayscale data OUT may include a set of bits indicating a grayscale value, such as the grayscale 1 and the grayscale 4 shown in
Next, in step S220, the blending circuit 120 receives the input grayscale data IN and dithered grayscale data IND, and the blending circuit 120 compares the dithered grayscale data IND with a first threshold TH1 to generate a blending weight BW. The first threshold TH1 is a reference grayscale for comparing and may be preset according to a design requirement, and the blending weight BW is computed to determine the weights of the input grayscale data IN and the dithered grayscale data IND. Specifically, the blending circuit 120 generates a blending weight BW by means of the dithered grayscale data IND, the first threshold TH1, and a gain value M1. The detail will be discussed in
In step S230, the blending circuit 120 performs a blending computing on the input grayscale data IN and the dithered grayscale data IND based on the blending weight BW to generate an output grayscale data OUT. In particular, the blending circuit 120 computes the output grayscale data OUT by blending the input grayscale data IN and the dithered grayscale data IND through the blending weight BW. The detail will be discussed thereafter.
Next, in step S320, the dither computing circuit 110 adds a dithering value to the truncated input grayscale data INT according to a lookup table (LUT), to generate the dithered grayscale data IND. There may be a plurality of dithering values in the lookup table, and the dithering values may be selected sequentially or randomly to be added into the each truncated input grayscale data INT, but not limited. For example, in
BW=(IN−TH1)*M1>>X (1)
When the difference (IN−TH1) indicates that the input grayscale data IN is not greater than the first threshold TH1, the blending circuit 120 generates zero as the blending weight BW. When the blending weight BW equals zero, the blending circuit 120 stops the dither computing and directly outputs the input grayscale data IN as the output grayscale data OUT, so as to save computer resource. In other words, when the input grayscale data IN is small enough, the output grayscale data OUT includes less part from the dithered grayscale data IND but includes more part from the input grayscale data IN. When the difference (IN−TH1) indicates that the input grayscale data IN is greater than the first threshold TH1 and not greater the second threshold TH2, the blending weight BW will be gradually increased to a maximum value of the blending weigh BWMAX with the input grayscale data IN, and the slope M of the blending weight BW versus the input grayscale data IN can be obtained through the grain value M1>>X. In other words, when the input grayscale data IN is greater, there is more part from the dithered grayscale data IND (while less part from the input grayscale data IN) included in the output grayscale data OUT.
When the difference (IN−TH1) indicates that the input grayscale data IN is greater than a second threshold TH2 (by comparing (IN−TH1) with (TH2−TH1)), the blending circuit 120 generates the predetermined value as the blending weight BW. It is noted that the maximum value of the blending weight BWMAX and the gain value M are preset according design requirements, and the second threshold TH2 could be computed by means of the first threshold TH1, the maximum value of the blending weight BWMAX and the gain value M.
When the blending weight BW equals a predetermined value which is the maximum value of the blending weigh BWMAX, the blending circuit 120 outputs the dithered grayscale data IND as the output grayscale data OUT, so as to save computer resource.
As shown in
The driving controller 706 may perform an image processing on an input grayscale data, and the data driving circuit 704 may provide driving signals to drive the pixel array 702 based on a processed grayscale data output from the driving controller 706. For example, the driving controller 706 in
In step S820, in response to that the image processing circuit 100 receives an input grayscale data IN (i.e. second input grayscale data) which is greater than a second threshold (i.e. the input grayscale data IN has a grayscale value greater than the second threshold), the image processing circuit 100 may generate a dithered grayscale data IND by performing a dither computing on the input grayscale data IN (i.e. second input grayscale data) and directly output the dithered grayscale data IND as the output grayscale data OUT (i.e. second output grayscale data). It should be noted that the second threshold is greater than the first threshold, and the output grayscale data OUT in step S820 does not comprise any part of the input grayscale data IN (i.e. second input grayscale data) not processed by the dither computing. In the aspect of the data driving circuit, in response to the input grayscale data IN (second input grayscale data) which is greater than the second threshold, the data driving circuit outputs a second driving signal to the pixel array based on the output grayscale data OUT (i.e. second output grayscale data which is equal to the dithered grayscale data IND) output from the driving controller.
Specifically, the image processing circuit 100 may have three operation modes. Referring to
In a third operation mode, both the dither computing circuit 110 and the blending circuit 120 receive a third input grayscale data IN which is greater than the first threshold and not greater the second threshold. Therefore, in the third operation mode, the dither computing circuit 110 performs the dither computing on the third input grayscale data IN to generate a second dithered grayscale data IND, and the blending circuit 120 performs a blending computing on the third input grayscale data IN and the second dithered grayscale data IND received from the dither computing circuit 110 to generate a blended grayscale data, and outputs the blended grayscale data as the third output grayscale data OUT.
Based on above, the blending computing of the disclosure decreases the dither ratio under the low input grayscale, leading to reduce the flicker phenomenon shown in LED display. Therefore, the side effect of the dither computing would be solved with a smooth gradient zone, so as to improve the user experience.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.
This application is a continuation-in-part application of and claims the priority benefit of a prior application Ser. No. 17/496,737, filed on Oct. 7, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
Number | Date | Country | |
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Parent | 17496737 | Oct 2021 | US |
Child | 17985901 | US |