In the first way, we can adjust the picture to grayscale mode. We open a picture and then adjust the color mode of the picture to grayscale.
The second method is to change the color picture into black and white by adjusting the hue/saturation. We just need to adjust the saturation value to the minimum.
The third method is to execute the image-adjust-black and white command, or you can adjust the color picture to black and white.
The fourth method is to decolorize the color picture.
The fifth method is to add a black and white adjustment layer to the picture. This method has the same principle as performing image-adjustment-black and white.