Pixpipe Overview

The point of Pixpipe is to be easy to use and easy to contribute to. This goal led to take some decisions:

• using a source bundler (Rollup)
• properly define a folder hierarchy within src:
  • core for the most low level interfaces and classes
  • decoder for specific file decoding and encoding
  • filter for all the filters (this could be arranged in a better way)
  • helper are like filters but the processing they provide is to help visualize data, rather that applying a scientifically relevant treatment. (ie. apply a colormap)
  • io for downloading/reading/writing files from the filesystem or AJAX
  • utils for hosting static functions (algebra, geometry, etc.)
  • pixpipe.js the main entry point where are listed all the modules
• A modular approach and a clear separation of objects.
• Once built, Pixpipe is only a single file, located in dist, so that's it's easy to import

If at any moment you need to know more about a specific function or class, you can read the code documentation.

Projects used in Pixpipe

Sometimes, it's just not worth reinventing the wheel. Here are the libraries Pixpipe uses and includes at build time:

• Pako, for high speed file compression/decompression in JS.
• FileSaver.js, to easily trigger file downloading to the user side
• expr-eval, to evaluate math expression and create quick filter prototype
• js-md5, to generate a unique checksum for each loaded files
• geotiff to decode Tiff and BigTiff images
• delaunay Delaunay triangulation
• jpeg-js a pure JS jpeg decoder
• UPNG.js a pure JS png decoder
• gl-matrix a great linear algebra lib. Its name comes from that it's compatible with WebGL vector/Matrix format (column major typed arrays)
• joi-browser a Javascript object schema validation lib that is easy to use
• ndarray multidim numerical arrays, used for some computations only (FFT), but not as a native data storage in Pixpipe
• nifti-reader-js an efficient NIfTI file parser

In order to make Pixpipejs the way it is, we have developped a few modules that are integrated at bundling time but that can also be used as stand-alone, without Pixpipe. They are all hosted on the Pixpipe Github organization:

• codecutils provides some static functions to encode or decode data, especially extract numerical array from ArrayBuffer without constraint, convert to unicode strings, etc.
• pixbincodec to read and write into the native Pixpipe format: PixBin files. Although this lib create or reads from ArrayBuffer, the exampled provided show how to read from or write to disk depending if you are using JS in a browser of in Node.
• mniobjparser to parse the 3D mesh/surface files output of CIVET, called MNI OBJ
• qeegmodfile a EEG file parser for the MOD format used in the Canada-China-Cuba consortium
• edfdecoder a EDF (European Data Format) file parser, especially used in EEG

Sample data

HERE is the repo where some sample data are stored (mainly to avoid this repos to be too fat).