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Crazy computer vision stuff in the browser
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Zeno Rocha
April 28, 2015
Programming
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1.1k
Crazy computer vision stuff in the browser
Zeno Rocha
April 28, 2015
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Transcript
CRAZY COMPUTER vision stuff in the browser
.html .css .js
zenorocha
None
None
None
None
None
computer vision ? what is
Persistence of vision
Persistence of vision
Motion perception
Motion perception
vimeo.com/108331968
Face detection
Face recognition
Autonomous robots
Autonomous robots
Virtual reality
Augmented reality
Augmented reality
how to do that?
None
None
how to do that in the browser?
1. Access the camera
None
Request user’s webcam navigator.getUserMedia({ video: true }, onSuccess, onFail);
Request user’s webcam navigator.getUserMedia({ video: true }, onSuccess, onFail);
Request user’s webcam navigator.getUserMedia({ video: true }, onSuccess, onFail);
2. Reproduce in a video
<video>
Get User Media callback function onSuccess(stream) { var video =
document.querySelector('video'); video.src = URL.createObjectURL(stream); video.onloadedmetadata = function(e) { // Done }; }
Get User Media callback function onSuccess(stream) { var video =
document.querySelector('video'); video.src = URL.createObjectURL(stream); video.onloadedmetadata = function(e) { // Done }; }
Get User Media callback function onSuccess(stream) { var video =
document.querySelector('video'); video.src = URL.createObjectURL(stream); video.onloadedmetadata = function(e) { // Done }; }
Get User Media callback function onSuccess(stream) { var video =
document.querySelector('video'); video.src = URL.createObjectURL(stream); video.onloadedmetadata = function(e) { // Done }; }
3. Obtain pixel matrix
<canvas>
4. Tracking algorithms
Request accepted Request access to the camera Reproduce camera <video>
Obtain pixel matrix <canvas> Tracking algorithms Result Summary
tracking.js
None
Maira Bello Team eduardo lundgren java pablo carvalho zeno rocha
100% JavaScript! Open source No dependencies Simple and intuitive API
Automatic setup Built-in tracking algorithms Easily extensible High performance Unit & performance regression tests ~ 7 Kb
tracker color
Demo
var tracker = new tracking.ColorTracker('magenta'); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); });
var tracker = new tracking.ColorTracker('magenta'); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); });
var tracker = new tracking.ColorTracker('magenta'); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); });
tracker object
Demo
var tracker = new tracking.ObjectTracker('face'); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); });
var tracker = new tracking.ObjectTracker('face'); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); });
var tracker = new tracking.ObjectTracker('face'); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); });
tracker custom
var MyTracker = function() { MyTracker.base(this, 'constructor'); }; tracking.inherits(MyTracker, tracking.Tracker);
MyTracker.prototype.track = function(pxs, width, height) { // Your code here this.emit('track', { // Your code here }); };
var MyTracker = function() { MyTracker.base(this, 'constructor'); }; tracking.inherits(MyTracker, tracking.Tracker);
MyTracker.prototype.track = function(pxs, width, height) { // Your code here this.emit('track', { // Your code here }); };
var MyTracker = function() { MyTracker.base(this, 'constructor'); }; tracking.inherits(MyTracker, tracking.Tracker);
MyTracker.prototype.track = function(pxs, width, height) { // Your code here this.emit('track', { // Your code here }); };
var MyTracker = function() { MyTracker.base(this, 'constructor'); }; tracking.inherits(MyTracker, tracking.Tracker);
MyTracker.prototype.track = function(pxs, width, height) { // Your code here this.emit('track', { // Your code here }); };
var tracker = new tracking.MyTracker(); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); });
var tracker = new tracking.MyTracker(); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); });
var tracker = new tracking.MyTracker(); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); });
who is using it?
kdzwinel.github.io/JS-face-tracking-demo
thedevilini.com/#masks
lessons learned
24 fps 60 fps 1000ms / 24fps = 41ms per
frame
24 fps 60 fps 1000ms / 24fps = 41ms per
frame
None
None
None
Int32Array Uint16Array Float64Array Uint8ClampedArray [ ] Typed arrays
jsperf.com/tracking-js-arrays
jsperf.com/tracking-js-arithmetic
Demo
None
None
web components > > -
how we create a component nowadays?
1. Never create! Just use a plugin
2. Copy & paste someone’s code
3. And hope it works
3. And hope it works
web components
web components Templates
web components Templates Custom Elements
web components Templates Custom Elements Shadow DOM
web components HTML Imports Templates Custom Elements Shadow DOM
None
var tracker = new tracking.ColorTracker('magenta'); tracking.track('#video', tracker, { camera: true
}); tracker.on('track', function(event) { event.data.forEach(function(rect) { // Your code goes here }); }); Remember?
Using Web Components… <video is="video-color-tracking" target="magenta" camera="true" ontrack="onResult" </video>
more ?
trackingjs.com
Where the magic happens Your comfort zone
Thanks! zenorocha.com @zenorocha
Thanks! zenorocha.com @zenorocha