Slice rectangle from an array with pixels.
clip(arr, shape=[w, h?, channels=4], rect=[x, y?, w?, h?])
var clip = require('clip-pixels')
var pixels = [
0, 1, 0,
1, 1, 1,
0, 1, 0
]
pixels = clip(pixels, [3, 3, 1], [1, 0, 2, 3])
/*
1, 0,
1, 1,
1, 0
*/