You don't need much to figure out a conditional, for example here you're dealing with two cases before and after 0.453, so just subtract this threshold from a value, divide this number by the absolute value of that number, and now you have -1 for a number before the threshold, and +1 for the number after the threshold. You can normalize it by dividing it by 2 and adding 0.5. Now you have a number `t` that is either 0 for the input before the threshold or 1 for the input after the threshold. You could use it to switch between two values like so: bt + a(1-t)

In the case of generating a white or black number, this works (unless you want a number between 0 and 255, then just multiply the result by 255): https://i.imgur.com/hXNw0EA.png