motion-detect
v0.2.5
Published
A node.js motion detection library that supports node.js streams
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Motion
A node.js motion detection library that supports node.js streams.
Using motion streams requires ImageMagick CLI tools to be installed. There's plenty of ways to install ImageMagick, choose what's right for you.
Install
npm install motion-detect
Motion Stream
Write images of any format to a motion stream, and the motion stream will emit, if motion is detected, objects of the format { time: 1394600350750, data: <Buffer ...> }
where time
is the moment the motion stream received the frame.
Usage
var request = require("request");
var MjpegConsumer = require("mjpeg-consumer");
var MotionStream = require("motion-detect").Stream;
var FileOnWrite = require("file-on-write");
var writer = new FileOnWrite({
path: './video',
ext: '.jpg',
filename: function(image) {
return image.time;
},
transform: function(image) {
return image.data;
},
sync: true
});
var consumer = new MjpegConsumer();
var motion = new MotionStream();
var username = "admin";
var password = "password";
var options = {
url: "http://192.168.1.5/videostream.cgi",
headers: {
'Authorization': 'Basic ' + new Buffer(username + ':' + password).toString('base64')
}
};
request(options).pipe(consumer).pipe(motion).pipe(writer);
Stream Options
minimumMotion: Number : default
2
: The minimum number of seconds of motion required before emitting dataprebuffer: Number : default
4
: The motion stream will cache and emit the prebuffer number of seconds of images prior to motion occurring.postbuffer: Number : default
4
: The motion stream will emit the postbuffer number of seconds of images after motion occurs.
Motion Object
Usage
var Motion = require('motion-detect').Motion;
var motion = new Motion();
var hasMotion = motion.detect(image1, image2);
Methods
detect(image1, [image2])
- image1
Array
ofNumber
- image2 (optional):
Array
ofNumber
Detect is called with one or two flat arrays of RGBA values. If called with one parameter, detect will use the last image1
as image2
.
var Motion = require('motion-detect').Motion;
var motion = new Motion();
// img1, img2, img3, img4 created ...
// all img's are strings of RGBA values
// and look like [128,128,128,255,...]
var hasMotion;
hasMotion = motion.detect(img1);
console.log(hasMotion);
// > false
hasMotion = motion.detect(img2);
console.log(hasMotion);
// > true
hasMotion = motion.detect(img3, img4);
console.log(hasMotion);
// > false
getLastImage()
Returns the last image.
var motion = new Motion();
console.log(motion.detect(img1));
// > false
console.log(motion.detect(img2));
// > true
console.log(img2 === motion.getLastImage());
// > true
getBlendedImage(image1, image2)
- image1
Array
ofNumber
- image2
Array
ofNumber
Returns an image with detected motion as white pixels on a black background in the form of a flat array of RGBA numbers.
About
Inspiration for this library comes from Romuald Quantin's excellent write up on motion detection in Javascript.