Color gamut conversion method, color gamut converter, display device, image signal conversion method, computer device and non-transitory storage medium

A color gamut converter, comprising:

• a signal receiver, a grayscale value generator, a target grayscale determiner and a grayscale upper limit determiner,
• wherein the signal receiver is configured to acquire RGB signals;
• the grayscale value generator is electrically connected with the signal receiver and configured to acquire a preset grayscale value of a white subpixel in each pixel of a converted image according to grayscale values of monochromatic subpixels in each pixel of an original image corresponding to the RGB signals, wherein the converted image is obtained by converting the original image from an RGB gamut to an RGBW gamut;
• the target grayscale determiner is electrically connected with the grayscale upper limit determiner and the grayscale value generator and configured to acquire a target grayscale value of the white subpixel at least according to a first maximum grayscale of the white subpixel and the preset grayscale value so as to set the target grayscale value of the white subpixel to be a value that is less than or equal to a minimum value of the first maximum grayscale and the preset grayscale value;
• and
• for a first saturation color patch in the original image, the grayscale upper limit determiner is configured to make a first maximum grayscale of a white subpixel corresponding to each pixel disposed in the first saturation color patch be equal to a grayscale threshold, wherein the grayscale threshold is less than a maximum grayscale value allowed by a display device.