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triangulate-image

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triangulate-image

installation

npm install triangulate-image

bower install triangulate-image

jspm install triangulate-image

what is it?

a javascript module that converts images to triangular polygons:

triangulated image of a. lincoln

for a live example, you can check out my triangulation editor online. there's also a list with example images, and transparency examples included in this repository.

how to use it

this library can be used in web browsers as well as in node.

it supports loading as an AMD module, as a CommonJS module or a global variable.

a simple example:

var params = { blur: 110, vertexCount: 700 };
var image = new Image();
 
image.onload = function () {
    triangulate(params)
        .fromImage(image)
        .toSVG()
        .then( function( svgMarkup ) {
            document.body.innerHTML = svgMarkup;
        } );
};
 
image.src = 'lincoln.jpg'

as you can see, there are three calls happening:

  1. triangulate() is called with the triangulation parameters
  2. then fromImage() is called with the input image as parameter
  3. and finally toSVG() is called to output svg markup.

when using the library, always follow these three steps: triangulation, input, output.

for an explanation of all available methods and parameters, check out the reference section below.

by default, all input and output methods are asynchronous and use promises for flow control. for most methods, there synchronous versions available as well. this library uses web workers for processing the image data where possible.

you can find more examples for both node and browser in the examples folder of this repository.

reference

triangulate()

triangulate() can take the following parameters

 
// the parameters listed are the default params 
 
var triangulationParams = {
    accuracy: 0.7,     // float beteween 0 and 1 
    blur: 40,          // positive integer 
    threshold: 50,     // integer between 1 and 100 
    vertexCount: 700,  // positive integer 
    fill: true,        // boolean or string with css color (e.g '#bada55', 'red', rgba(100,100,100,0.5)) 
    stroke: true,      // boolean or string with css color (e.g '#bada55', 'red', hsla(0, 50%, 52%, 0.5)) 
    strokeWidth: 0.5,  // positive float 
    gradients: true,   // boolean 
    gradientStops: 4,  // positive integer >= 2 
    lineJoin: 'miter', // 'miter', 'round', or 'bevel' 
    transparentColor: false // boolean false or string with css color 
};
 

it returns an object containing all input methods.

fromImage()

fromImage() expects an Image object as its only parameter. it returns an object containing all input methods.

example:

var image = new Image();
 
image.onload = function () {
    triangulate()
        .fromImage( image )
        .toSVG()
        .then ( function ( svgMarkup ) {
            document.body.innerHTML = svgMarkup;
        } );
};
 
image.src = 'lincoln.jpg'

please note: this method is not available in node. important: when using the library in a browser, make sure the image was loaded before triangulating it.

fromImageSync()

fromImageSync() expects an Image object as its only parameter. it returns an object containing all input methods. it is the synchronous version of fromImage().

example:

var image = new Image();
 
image.onload = function () {
    document.body.innerHTML = triangulate().fromImageSync( image ).toSVG();
};
 
image.src = 'lincoln.jpg'

please note: this method is not available in node. important: when using the library in a browser, make sure the image was loaded before triangulating it.

fromImageData()

fromImageData() expects an ImageData object as its only parameter. it returns an object containing all input methods.

example:

var canvas = document.createElement( 'canvas' );
var ctx = canvas.getContext( '2d' );
 
ctx.fillStyle = 'red';
ctx.fillRect( 30, 30, 90, 45 );
ctx.fillStyle = 'green';
ctx.fillRect( 10, 20, 50, 60 );
 
var imageData = ctx.getImageData( 0, 0, canvas.width, canvas.height );
 
triangulate()
    .fromImageData( imageData )
    .toSVG()
    .then( function ( svgMarkup ) {
        document.body.innerHTML = svgMarkup;
    } );

fromImageDataSync()

fromImageDataSync() expects an ImageData object as its only parameter. it returns an object containing all input methods. it is the synchronous version of fromImageData().

example:

var canvas = document.createElement( 'canvas' );
var ctx = canvas.getContext( '2d' );
 
ctx.fillStyle = 'red';
ctx.fillRect( 30, 30, 90, 45 );
ctx.fillStyle = 'green';
ctx.fillRect( 10, 20, 50, 60 );
 
var imageData = ctx.getImageData( 0, 0, canvas.width, canvas.height );
 
document.body.innerHTML = triangulate().fromImageDataSync( imageData ).toSVG();

fromBuffer()

fromBuffer() expects a Buffer object as its only parameter. it returns an object containing all input methods.

it uses image#src=buffer from node-canvas internally.

example:

var fs = require('fs');
 
fs.readFile( './lincoln.jpg', function ( err, buffer ) {
    if ( err ) { throw err; }
        
    triangulate()
        .fromBuffer( buffer )
        .toSVG()
        .then( function ( svgMarkup ) {
            fs.writeFile( './lincoln.svg', svgMarkup, function ( err ) {
                if ( err ) { throw err; }
                console.log( 'created an svg file.' );
            } );
        } );
} );

please note: this method is only available in node.

fromBufferSync()

fromBufferSync() expects a Buffer object as its only parameter. it returns an object containing all input methods. it is the synchronous version of fromBuffer().

it uses image#src=buffer from node-canvas internally.

example:

var fs = require('fs');
 
fs.readFile( './lincoln.jpg', function ( err, buffer ) {
    if ( err ) { throw err; }
        
    var svgMarkup = triangulate().fromBufferSync( buffer ).toSVGSync();
 
    fs.writeFile( './lincoln.svg', svgMarkup, function ( err ) {
        if ( err ) { throw err; }
        console.log( 'created an svg file.' );
    } );
} );

please note: this method is only available in node.

fromStream()

fromStream() expects a ReadableStream object as its only parameter. it returns an object containing all input methods.

it uses image#src=buffer from node-canvas internally.

example:

var fs = require('fs');
 
var inputStream = fs.createReadStream( './lincoln.jpg' );
var outputStream = fs.createWriteStream( './lincoln-triangulated.png' );
 
triangulate( params )
    .fromStream( inputStream )
    .toPNGStream()
    .then( function ( pngStream ) {
        pngStream.on( 'data', function ( chunk ) { outputStream.write( chunk ); } );
        pngStream.on( 'end', function () { console.log( 'png file saved.' ); } );
    } );

please note: this method is only available in node. currently, theres no input sanitation for this method, so you'll want to make sure that the input stream is an image.

toDataURL()

toDataURL() can take the following parameters:

var dataUrlParams = {
    dpr: 1                   // positive number, short for devicePixelRatio, 
    backgroundColor: 'green' // background color of image. not set: transparent background 
};
 

it returns a String containing the base64-encoded image url.

example:

var image = new Image();
 
image.onload = function () {
    triangulate()
        .fromImage( image )
        .toDataURL()
        .then( function ( dataURL ) {
            document.body.style.background = 'url(' + dataURL + ')';
        } );
};
 
image.src = 'lincoln.jpg'

toDataURLSync()

toDataURLSync() can take the following parameters:

var dataUrlParams = {
    dpr: 1                   // positive number, short for devicePixelRatio, 
    backgroundColor: 'green' // background color of image. not set: transparent background 
};
 

it is the synchronous version of toDataUrl().

it returns a String containing the base64-encoded image url.

example:

var image = new Image();
 
image.onload = function () {
    var dataURL = triangulate()
        .fromImageSync( image )
        .toDataURLSync();
 
    document.body.style.background = 'url(' + dataURL + ')';
};
 
image.src = 'lincoln.jpg'

toImageData()

toImageData() can take the following parameters:

var imageDataParams = {
    dpr: 1                   // positive number, short for devicePixelRatio, 
    backgroundColor: 'green' // background color of image. not set: transparent background 
};
 

it returns an ImageData object.

example:

var image = new Image();
 
image.onload = function () {
    triangulate()
        .fromImage( image )
        .toImageData()
        .then( function ( imageData ) {
            var canvas = document.createElement( 'canvas' );
            var ctx = canvas.getContext( '2d' );
            ctx.putImageData( imageData, 0, 0 );
 
            document.body.appendChild( canvas );
        } );
};
 
image.src = 'lincoln.jpg'

toImageDataSync()

toImageDataSync() can take the following parameters:

var imageDataParams = {
    dpr: 1                   // positive number, short for devicePixelRatio, 
    backgroundColor: 'green' // background color of image. not set: transparent background 
};
 

it returns an ImageData object.

it is the synchronous version of toImageData().

example:

var image = new Image();
 
image.onload = function () {
    var imageData = triangulate()
        .fromImageSync( image )
        .toImageDataSync();
    
    var canvas = document.createElement( 'canvas' );
    var ctx = canvas.getContext( '2d' );
    ctx.putImageData( imageData, 0, 0 );
 
    document.body.appendChild( canvas );
};
 
image.src = 'lincoln.jpg'

toSVG()

toSVG() does not take any parameters. it returns a String with svg markup.

example:

var params = { blur: 110, vertexCount: 700 };
var image = new Image();
 
image.onload = function () {
    triangulate( params )
        .fromImage( image )
        .toSVG()
        .then( function ( svgMarkup ) {
            document.body.innerHTML = svgMarkup;
        } );
};
 
image.src = 'lincoln.jpg'

toSVGSync()

toSVGSync() does not take any parameters. it returns a String with svg markup. it is the synchronous version of toSVG().

example:

var params = { blur: 110, vertexCount: 700 };
var image = new Image();
 
image.onload = function () {
    document.body.innerHTML = triangulate( params ).fromImageSync( image ).toSVGSync();
};
 
image.src = 'lincoln.jpg'

toData()

toData() does not take any parameters. it returns an Array with the data for all polygons.

example:

var image = new Image();
 
image.onload = function () {
    triangulate()
        .fromImage( image )
        .toData()
        .then( function ( polygonData ) {
            console.log( polygonData );
        } );
};
 
image.src = 'lincoln.jpg'

toDataSync()

toDataSync() does not take any parameters. it returns an Array with the data for all polygons. it is the synchronous version of toData().

example:

var image = new Image();
 
image.onload = function () {
    console.log( triangulate().fromImageSync( image ).toDataSync() );
};
 
image.src = 'lincoln.jpg'

toBuffer()

toBuffer() can take the following parameters:

var bufferParams = {
    format: 'svg' // 'svg', 'pdf' or undefined 
};
 

it uses canvas#tobuffer from node-canvas internally.

it returns a Buffer object.

example:

var fs = require('fs');
 
fs.readFile( './lincoln.jpg', function ( err, buffer ) {
    if ( err ) { throw err; }
        
    triangulate()
        .fromBuffer( buffer )
        .toBuffer( { format: 'pdf' } )
        .then( function ( imageBuffer ) {
            fs.writeFile( './lincoln.pdf', imageBuffer, function ( err ) {
                if ( err ) { throw err; }
                console.log( 'created a pdf file.' );
            } );
        } );
} );

please note: this method is only available in node.

toBufferSync()

toBufferSync() can take the following parameters:

var bufferParams = {
    format: 'svg' // 'svg', 'pdf' or undefined 
};
 

it is the synchronous version of toBuffer(). it uses canvas#tobuffer from node-canvas internally.

it returns a Buffer object.

example:

var fs = require('fs');
 
fs.readFile( './lincoln.jpg', function ( err, buffer ) {
    if ( err ) { throw err; }
        
    var imageBuffer = triangulate().fromBufferSync( buffer ).toBufferSync( { format: 'pdf' } );
 
    fs.writeFile( './lincoln.pdf', imageBuffer, function ( err ) {
        if ( err ) { throw err; }
        console.log( 'created a pdf file.' );
    } );
} );

please note: this method is only available in node.

toJPGStream()

toJPGStream() can take the following parameters:

var jpgStreamParams = {
    bufsize: 4096,          // output buffer size in bytes 
    quality: 75,            // jpg quality (0-100) default: 75 
    progressive: false,     // true for progressive compression 
    dpr: 1,                 // positive number, short for devicePixelRatio, 
    backgroundColor: '#fff' // btw: there are no transparent backgrounds in jpg. 
};
 

it uses canvas#jpegstream() from node-canvas internally.

it returns a JPEGStream object.

example:

var fs = require('fs');
fs.readFile( '.lincoln.jpg', function ( err, buffer ) {
    if ( err ) { throw err; }
 
    var fileStream = fs.createWriteStream( './triangulatedLincoln.jpg' );
    var jpgStream = triangulate().fromBuffer( buffer ).toJPGStream( { backgroundColor: 'red' } );
    
    jpgStream.on( 'data', function ( chunk ) { fileStream.write( chunk ); } );
    jpgStream.on( 'end', function () { console.log( 'jpg file created.' ); } );
} );

please note: this method is only available in node.

toJPEGStream()

see toJPGStream().

toPNGStream()

toPNGStream() can take the following parameters:

var jpgStreamParams = {
    dpr: 1,                 // positive number, short for devicePixelRatio, 
    backgroundColor: '#fff' // background color of image. not set: transparent background 
};
 

it uses canvas#pngstream() from node-canvas internally.

it returns a PNGStream object.

example:

var fs = require('fs');
fs.readFile( '.lincoln.jpg', function ( err, buffer ) {
    if ( err ) { throw err; }
 
    var fileStream = fs.createWriteStream( './triangulatedLincoln.png' );
    var pngStream = triangulate().fromBuffer( buffer ).toPNGStream( { backgroundColor: 'blue' } );
    
    pngStream.on( 'data', function ( chunk ) { fileStream.write( chunk ); } );
    pngStream.on( 'end', function () { console.log( 'png file created.' ); } );
} );

please note: this method is only available in node.

toSVGStream()

toSVGStream() can't take any parameters.

it returns a ReadableStream object.

example:

var fs = require('fs');
fs.readFile( '.lincoln.jpg', function ( err, buffer ) {
    if ( err ) { throw err; }
 
    var svgStream = triangulate().fromBuffer( buffer ).toSVGStream();
    svgStream.pipe( process.stdout );
} );

please note: this method is only available in node.

in node

when used in node, this library has a dependency on the node-canvas module. node-canvas may require some extra steps to get it to work on some platforms.

development

npm run build will build the node-ready and browser-ready versions, which are saved to the dist-node and dist directories.

npm run test will run the tests in both the browser and node.

license

mit

third party code

some parts of the code were taken from the triangulation image generator by akm2 (MIT license).

most of the folder structure and the npm script setup were taken from nonalnawson's hello javascript repo (Apache-2.0 license).

dependencies:

more information

this repository contains a changelog and an authors file with even more information.

missing something?

found a bug? missing a feature? are you using this library in an interesting project? take a look at the issues, open a pull request and let me know.

most importantly

thank you for taking a look at this repo. have a great day :)