let n0 = image.test_pattern { pattern: "checker", size: 64 };
let n1 = image.threshold(image: n0.image.clone()) { threshold: 128 };
let n2 = image.morphology(image: n1.binary) { kernel_size: 3, operation: "erode" };
let n3 = vision.blobs(binary: n2.result) { min_area: 16 };
let n4 = vision.draw_detections(image: n0.image, detections: n3.detections.clone());