Way to build image pixel by pixel?

Hello,

I'd like to visualize a simplex noise map by representing the values as shades of gray on a 2d image.

While using Processing/p5js I used to be able to access the pixels array and then set the values and update the image. Is there any similar way of achieving this in pixi, or should I look elsewhere?
If I had to build the image in p5, can I convert it to a pixi texture right away? (meaning, without intermediately saving it to disk or similar)