Converting a number to a greyscale color in Java

问题

I'm trying to figure out how I can convert a number between 1 and 50 to a greyscale color that could be used here:

g.setColor(MyGreyScaleColour);

1 would be lightest (white) and 50 would be darkest (black).

e.g.

Color intToCol(int colNum)  
{  
code here  
}  

Any suggestions?

回答1:

Java uses RGB colors where each component (Red, Green, Blue) ranges from 0-255. When all components have the same value, you end up with a white-black-gray color. Combinations closer to 255 would be more white and closer to 0 would be all black. The function below would return a grayish color, with the amount of white scaled accordingly with the input.

Color intToCol(int colNum)
{
  int rgbNum = 255 - (int) ((colNum/50.0)*255.0);
  return new Color (rgbNum,rgbNum,rgbNum);
}

回答2:

Something like:

float grey = (50 - colNum) / 49f;
return new Color(grey, grey, grey);

来源：https://stackoverflow.com/questions/2780546/converting-a-number-to-a-greyscale-color-in-java