MovementBasedSegmenter

Last updated 29 days ago

MovementBasedSegmenter's turn to locate and classify fruits.

Let's create an initialization function for the MBS watcher.

const initializeMBS = () => {};

Once again, retrieve the elements we'll be working with, along with the bounding rect of the element defining the watcher's contour.

const initializeMBS = () => {
const mbsElement = document.getElementsByClassName('mbs')[0];
const mbsBounds = mbsElement.getBoundingClientRect();
};

Just like NeuralNetworkClassifier (and all watchers, for that matter), MBS also has its classification trigger on the onClassification callback. However, MovementBasedSegmenter has a secondary callback, triggered prior to onClassification, named onLocation. This is because MBS first determines the location of an object and then it classifies it. onLocation is generally used to create a loading animation for a located, not yet classified object.

For the sake of simplicity, we will focus on onClassification in this guide.

const initializeMBS = () => {
const mbsElement = document.getElementsByClassName('mbs')[0];
const mbsBounds = mbsElement.getBoundingClientRect();
const onClassification = (classifiedObjects) => classifiedObjects.forEach((classifiedObject) => {
handleObjectClassified(classifiedObject, '#FFFFFF');
});
const onLocation = (locatedObjects) => {
// This step fires before onClassification!
console.log(locatedObjects);
};
const mbsFruitsWatcher = {
name: 'MovementBasedSegmenter',
shape: lampix.helpers.rectangle(
mbsBounds.left,
mbsBounds.top,
mbsBounds.width,
mbsBounds.height
),
params: {
neural_network_name: 'fruits'
},
onLocation,
onClassification
};
};

Let's also add the utility mentioned above to add DOM elements for each classified object (remember to import it):

// handleObjectClassified.js
const handleObjectClassified = (obj, color) => {
const el = document.createElement('div');
el.classList.add('mbs-object');
el.style.borderColor = color;
el.style.left = `${obj.centerPoint.posX - 25}px`;
el.style.top = `${obj.centerPoint.posY - 25}px`;
el.textContent = obj.classTag;
document.body.appendChild(el);
};
export default handleObjectClassified;

All that's left is telling Lampix about this watcher too, by adding the following to the end of the initializeMBS function.

// ...
lampix.watchers.add(mbsFruitsWatcher);

Now, initializeMBS should look like this:

const initializeMBS = () => {
const mbsElement = document.getElementsByClassName('mbs')[0];
const mbsBounds = mbsElement.getBoundingClientRect();
const onClassification = (classifiedObjects) => classifiedObjects.forEach((classifiedObject) => {
handleObjectClassified(classifiedObject, '#FFFFFF');
});
const onLocation = (locatedObjects) => {
// This step fires before onClassification!
console.log(locatedObjects);
};
const mbsFruitsWatcher = {
name: 'MovementBasedSegmenter',
shape: lampix.helpers.rectangle(
mbsBounds.left,
mbsBounds.top,
mbsBounds.width,
mbsBounds.height
),
params: {
neural_network_name: 'fruits'
},
onLocation,
onClassification
};
lampix.watchers.add(mbsFruitsWatcher);
};