speedy-vision
Version:
GPU-accelerated Computer Vision for JavaScript
164 lines (139 loc) • 5.2 kB
HTML
<!--
speedy-vision.js
GPU-accelerated Computer Vision for JavaScript
Copyright 2020-2022 Alexandre Martins <alemartf(at)gmail.com>
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
median-filter.html
Blurring a video with a median filter
-->
<html>
<head>
<meta charset="utf-8">
<meta name="description" content="speedy-vision.js: GPU-accelerated Computer Vision for JavaScript">
<meta name="author" content="Alexandre Martins">
<title>Blurring a video with a median filter</title>
<script src="../dist/speedy-vision.js"></script>
<link href="style.css" rel="stylesheet">
</head>
<body>
<h1>Median filter</h1>
<form autocomplete="off">
<div>
<label for="kernel-size">Kernel size:</label>
<select id="kernel-size">
<option value="3" selected>3x3</option>
<option value="5">5x5</option>
<option value="7">7x7</option>
</select>
</div>
<div>
<label for="speed-slider">Video speed</label>
<input type="range" id="speed-slider" min="0.10" max="2" value="1" step="0.01">
</div>
</form>
<div>
<span id="status"></span>
<canvas id="canvas-demo"></canvas>
</div>
<video
src="../assets/bird-walking.webm"
poster="../assets/loading.jpg"
preload="auto"
loop muted hidden
title="Free video by Wendy Laplume, https://www.pexels.com/pt-br/video/passaro-ave-passarinho-concreto-4168986/">
</video>
<script>
window.onload = async function()
{
/*
This is our pipeline:
Image ---> Convert to ---> Median ---> Image
Source greyscale Blur Sink
|
|
+-------------> Image
Sink
*/
// Load a video
const video = document.querySelector('video');
const media = await Speedy.load(video);
video.play();
// Setup the pipeline
const pipeline = Speedy.Pipeline();
const source = Speedy.Image.Source();
const sink1 = Speedy.Image.Sink('median');
const sink2 = Speedy.Image.Sink('greyscale');
const greyscale = Speedy.Filter.Greyscale();
const median = Speedy.Filter.MedianBlur();
source.media = media;
median.kernelSize = Speedy.Size(3,3);
source.output().connectTo(greyscale.input());
greyscale.output().connectTo(median.input());
median.output().connectTo(sink1.input());
greyscale.output().connectTo(sink2.input());
pipeline.init(source, sink1, sink2, greyscale, median);
// Setup the input controls
const kernelSize = document.getElementById('kernel-size');
const speedSlider = document.getElementById('speed-slider');
speedSlider.oninput = () => video.playbackRate = speedSlider.value;
kernelSize.oninput = () => median.kernelSize = Speedy.Size(kernelSize.value, kernelSize.value);
// Main loop
(function() {
const canvas = createCanvas(media.width * 2, media.height, video.title);
let median = null, greyscale = null, frameReady = false;
async function update()
{
const result = await pipeline.run();
median = result.median;
greyscale = result.greyscale;
frameReady = true;
setTimeout(update, 1000 / 60);
}
update();
function render()
{
if(frameReady) {
draw(median, canvas, 0, 0);
draw(greyscale, canvas, median.width, 0);
}
frameReady = false;
requestAnimationFrame(render);
}
render();
setInterval(renderStatus, 200);
})();
}
function createCanvas(width, height, title)
{
const canvas = document.getElementById('canvas-demo') || document.createElement('canvas');
canvas.width = width;
canvas.height = height;
canvas.title = title;
if(!document.body.contains(canvas))
document.body.appendChild(canvas);
return canvas;
}
function renderStatus()
{
const status = document.getElementById('status');
status.innerText = `FPS: ${Speedy.fps}`;
}
function draw(media, canvas, x = 0, y = 0, width = media.width, height = media.height)
{
const ctx = canvas.getContext('2d');
ctx.drawImage(media.source, x, y, width, height);
}
</script>
<mark>Powered by <a href="https://github.com/alemart/speedy-vision">speedy-vision.js</a></mark>
</body>
</html>