hqx Pixel Art Scaling Algorithm in JavaScript
JavaScript HTML
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phoboslab Merge pull request #8 from abamacus/master
Fixed javascript security error
Latest commit dfe3d0c Oct 30, 2015
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README.md typo Dec 29, 2010
hqx.js Fix for devices with backingStorePixelRatio != 1 Nov 13, 2012
test.html Fixed javascript security error Oct 30, 2015
test.png Initial commit Dec 29, 2010



hqx Pixel Art Scaling Algorithm for JavaScript/Canvas

This project is a direct port of the C source code for the hqx scaling algorithm. It uses the HTML5 Canvas element to get an manipulate pixel data of an image.

The source is unoptimized and probably many times slower than it could be. RGBA components are first packed into integers processed by hqx and then unpacked again. The source is pretty large (~400kb), because all 3 hqx scaling algorithms are included, but it can be gzipped quite well (~27kb).

Some basic support for alpha transparency has been added.


Simple Test Image

Biolab Disaster Scaled With hqx


var scaledCanvas = hqx( originalImage, 3 );

The second argument is the scaling factor. hqx supports 2, 3 and 4. See test.html for an example.