speedy-vision
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GPU-accelerated Computer Vision for JavaScript
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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.
greyscale-video.html
Convert a video to greyscale
-->
<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>Convert video to greyscale</title>
<script src="../dist/speedy-vision.js"></script>
<link href="style.css" rel="stylesheet">
</head>
<body>
<h1>Convert video to greyscale</h1>
<video
src="../assets/flying-eagle.webm"
poster="../assets/loading.jpg"
preload="auto"
loop muted controls autoplay
title="Free video by Cinema Professionals, https://www.pexels.com/pt-br/video/assistindo-a-aguia-voar-3635378/">
</video>
<div>
<span id="status"></span>
<canvas id="canvas-demo"></canvas>
</div>
<script>
window.onload = async function()
{
/*
This is our pipeline:
Image ---> Convert to ---> Image
Source greyscale Sink
*/
// Load a video
const video = document.querySelector('video');
const media = await Speedy.load(video);
// Setup the pipeline
const pipeline = Speedy.Pipeline(); // create the pipeline and the nodes
const source = Speedy.Image.Source();
const sink = Speedy.Image.Sink();
const greyscale = Speedy.Filter.Greyscale();
source.media = media; // set the media source
source.output().connectTo(greyscale.input()); // connect the nodes
greyscale.output().connectTo(sink.input());
pipeline.init(source, sink, greyscale); // add the nodes to the pipeline
// Main loop
(function() {
const canvas = createCanvas(media.width, media.height, video.title);
let image = null, frameReady = false;
async function update()
{
const result = await pipeline.run();
image = result.image;
frameReady = true;
setTimeout(update, 1000 / 60);
}
update();
function render()
{
if(frameReady) {
draw(image, canvas);
}
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>