@webarkit/jsfeat-next
Version:
Typescript version of jsfeat for WebARKit
184 lines (153 loc) • 6.88 kB
HTML
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="description" content="A JavaScript Computer Vision Library">
<title>JSFeatNext - JavaScript Computer Vision Library.</title>
<link rel="stylesheet"
href="https://fonts.googleapis.com/css?family=Droid+Sans:regular,bold|Inconsolata|PT+Sans:400,700">
<link rel="stylesheet" href="css/bootstrap.css">
<link rel="stylesheet" href="css/jsfeat.css">
</head>
<body>
<video id="webcam" width="640" height="480" style="display:none;"></video>
<div style=" width:640px;height:480px;margin: 10px auto;">
<canvas id="canvas" width="640" height="480"></canvas>
<div id="no_rtc" class="alert alert-error" style="display:none;"></div>
<div id="log" class="alert alert-info"></div>
</div>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script src="../dist/jsfeatNext.js"></script>
<script type="text/javascript" src="js/compatibility.js"></script>
<script type="text/javascript" src="js/profiler.js"></script>
<script type="text/javascript" src="js/dat.gui.min.js"></script>
<script type="text/javascript">
$(window).on('load', function () {
"use strict";
// lets do some fun
var video = document.getElementById('webcam');
var canvas = document.getElementById('canvas');
var jsfeat = jsfeatNext.jsfeatNext;
var imgproc = new jsfeat.imgproc();
var fast_corners = new jsfeat.fast_corners();
try {
var attempts = 0;
var readyListener = function (event) {
findVideoSize();
};
var findVideoSize = function () {
if (video.videoWidth > 0 && video.videoHeight > 0) {
video.removeEventListener('loadeddata', readyListener);
onDimensionsReady(video.videoWidth, video.videoHeight);
} else {
if (attempts < 10) {
attempts++;
setTimeout(findVideoSize, 200);
} else {
onDimensionsReady(640, 480);
}
}
};
var onDimensionsReady = function (width, height) {
demo_app(width, height);
compatibility.requestAnimationFrame(tick);
};
video.addEventListener('loadeddata', readyListener);
compatibility.getUserMedia({
video: true
}, function (stream) {
if (video.srcObject !== undefined) {
video.srcObject = stream
} else {
try {
video.src = compatibility.URL.createObjectURL(stream);
} catch (error) {
video.src = stream;
}
}
setTimeout(function () {
video.play();
}, 500);
}, function (error) {
$('#canvas').hide();
$('#log').hide();
$('#no_rtc').html('<h4>WebRTC not available.</h4>');
$('#no_rtc').show();
});
} catch (error) {
$('#canvas').hide();
$('#log').hide();
$('#no_rtc').html('<h4>Something goes wrong...</h4>');
$('#no_rtc').show();
}
var stat = new profiler();
var gui, options, ctx, canvasWidth, canvasHeight;
var img_u8, corners, threshold;
var demo_opt = function () {
this.threshold = 20;
}
function demo_app(videoWidth, videoHeight) {
canvasWidth = canvas.width;
canvasHeight = canvas.height;
ctx = canvas.getContext('2d', {"willReadFrequently": true});
ctx.fillStyle = "rgb(0,255,0)";
ctx.strokeStyle = "rgb(0,255,0)";
img_u8 = new jsfeat.matrix_t(640, 480, jsfeat.U8_t | jsfeat.C1_t);
corners = [];
var i = 640 * 480;
while (--i >= 0) {
corners[i] = new jsfeat.keypoint_t(0, 0, 0, 0);
}
threshold = 20;
fast_corners.set_threshold(threshold);
options = new demo_opt();
gui = new dat.GUI();
gui.add(options, 'threshold', 5, 100).step(1);
stat.add("grayscale");
stat.add("fast corners");
}
function tick() {
compatibility.requestAnimationFrame(tick);
stat.new_frame();
if (video.readyState === video.HAVE_ENOUGH_DATA) {
ctx.drawImage(video, 0, 0, 640, 480);
var imageData = ctx.getImageData(0, 0, 640, 480);
stat.start("grayscale");
imgproc.grayscale(imageData.data, 640, 480, img_u8);
stat.stop("grayscale");
if (threshold != options.threshold) {
threshold = options.threshold | 0;
fast_corners.set_threshold(threshold);
}
stat.start("fast corners");
var count = fast_corners.detect(img_u8, corners, 5);
stat.stop("fast corners");
// render result back to canvas
var data_u32 = new Uint32Array(imageData.data.buffer);
render_corners(corners, count, data_u32, 640);
ctx.putImageData(imageData, 0, 0);
$('#log').html(stat.log());
}
}
function render_corners(corners, count, img, step) {
var pix = (0xff << 24) | (0x00 << 16) | (0xff << 8) | 0x00;
for (var i = 0; i < count; ++i) {
var x = corners[i].x;
var y = corners[i].y;
var off = (x + y * step);
img[off] = pix;
img[off - 1] = pix;
img[off + 1] = pix;
img[off - step] = pix;
img[off + step] = pix;
}
}
$(window).on('unload', function () {
video.pause();
video.src = null;
});
});
</script>
</body>
</html>