Method and device for adjusting greyscale of display panel solving problem of ineffectiveness of eliminating unevenness caused by inaccurate mura compensation value

A method for adjusting greyscale of display panel, wherein, the method comprises:

• performing image capture on the display panel, and obtaining a current image;
• identifying an uneven area in the current image, and detecting original output brightness and original input grayscale of the uneven area;
• determining target input grayscale corresponding to preset target brightness according to actual Gamma curve value which is obtained by testing the display panel;
• using the difference between the original input grayscale and the target input grayscale as grayscale compensation value of the uneven area;
• obtaining a plurality of target brightness values respectively corresponding to a plurality of preset grayscale except 255 grayscale according to the actual Gamma curve;
• obtaining a first common voltage when the display panel displays a 255 grayscale image;
• obtaining a second common voltage via increasing or decreasing the first common voltage by a preset voltage offset;
• inputting the second common voltage to the display panel, and sequentially inputting a plurality of initial grayscale voltages corresponding to the plurality of preset grayscale to the display panel, continuously adjusting each initial grayscale voltage until the brightness of the display panel reaches the target brightness value corresponding to preset grayscale corresponding to the initial grayscale voltage every time the initial grayscale voltage is input, and obtaining a plurality of modified grayscale voltages corresponding to the plurality of preset grayscale;
• and
• driving the display panel to display by using the second common voltage, the plurality of modified grayscale voltages, and a preset initial grayscale voltage corresponding to 255 grayscale.