@nutshelllabs/png-js
v2.2.1
Published
A PNG decoder in JS
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@nutshelllabs/png-js
A PNG decoder in JS for the canvas element or Node.js.
Acknowledges
This project is a fork of png.js by @devongovett and continued under the scope of this project since it has react-pdf specific features. Any recongnition should go to him and the original project mantainers.
About this fork
Updated to 977b857a11676c1e720e79ed8d9178a005a9abd6
- Build node and browser specific bundles
- Uses rollup for build
Browser Usage
Simply include png.js and zlib.js on your HTML page, create a canvas element, and call PNG.load to load an image.
<canvas></canvas>
<script src="zlib.js"></script>
<script src="png.js"></script>
<script>
var canvas = document.getElementsByTagName('canvas')[0];
PNG.load('some.png', canvas);
</script>
The source code for the browser version resides in png.js
and also supports loading and displaying animated PNGs.
Node.js Usage
Install the module using npm
sudo npm install png-js
Require the module and decode a PNG
var PNG = require('png-js');
PNG.decode('some.png', function(pixels) {
// pixels is a 1d array (in rgba order) of decoded pixel data
});
You can also call PNG.load
if you want to load the PNG (but not decode the pixels) synchronously. If you already
have the PNG data in a buffer, simply use new PNG(buffer)
. In both of these cases, you need to call png.decode
yourself which passes your callback the decoded pixels as a buffer. If you already have a buffer you want the pixels
copied to, call copyToImageData
with your buffer and the decoded pixels as returned from decodePixels
.