09 December 2012

Introducing Pictish, an image-processing library for web browsers

Boy, between RaphaëlTS, SHA-1, and Haeckel, I've been releasing an awful lot of TypeScript/JavaScript libraries lately, haven't I? Anyway, here's another!

Pictish takes advantage of canvas elements and Typed Arrays to provide fast routines for processing raster image data. Here is a rundown of the currently available functions:
  • createImageData()
  • fromFile()
  • fromHTMLImage()
  • crop()
  • flipX()
  • flipY()
  • scaleDown()
  • quarter()
  • silhouettize()
All of these functions have been tested and optimized. More information is available in the documentation at the BitBucket site. Note that since canvas elements and Typed Arrays are based on more recent specifications, not all browsers support it. (For what it's worth, I've been testing in Chrome.)

(The sharp-eyed may notice that last function and wonder if it might have something to do with another project of mine. The answer is yes.)

Next planned step is to create a PNG file encoder  that could take a while, though.

08 December 2012

SHA-1 with Typed Arrays

There are already SHA-1 implementations for JavaScript, but all the ones I found use strings as input. This is fine for generating hashes from small amounts of data, but not so great for large binary files. So I've created a SHA-1 library that optionally accepts ArrayBuffer objects.

Note that this will not work on browsers that do not support Typed Arrays.

I ran some tests and found that in Chrome it takes less than half a second to hash 10Mb of data.

Hope someone finds this useful! (At the very least, I will.)

02 December 2012

Haeckel: A Code Library for Browser-Based Evolutionary Diagrams

For a while now I've been writing posts with diagrams like this one, showing the evolution of cranial capacity in mangani over the past seven million years:

How did I make them? Originally it was all ad-hoc ActionScript code, but more recently I've begun to organize the code into a library and translate it into TypeScript (which, in turn, is automatically translated into JavaScript). Although this library is still in progress, I've decided it's at a stage where I can open it to the general public.

This library includes functionality for:

  • Modeling scientific concepts such as taxa, phylogeny, character states, stratigraphy, and geography.
  • Processing scientific data (notably calculating morphological distance and inferring unknown character states).
  • Rendering data into charts as Scalable Vector Graphics, using RaphaëlJS.
For a while I struggled with what to call this library. It's neither purely about science nor purely about graphics. Finally I got my inspiration from RaphaëlJS, a graphics library named after a great artist. I named my library after a man who was both a great artist and a great biologist: