r1015 / display

Lightweight browser-based display server

display: a browser-based graphics server

Originally forked from gfx.js.

The initial goal was to remain compatible with the torch/python API of gfx.js, but remove the term.js/tty.js/pty.js stuff which is served just fine by ssh.

Compared to gfx.js:

• no terminal windows (no term.js)
• dygraphs instead of nvd3 (have built in zoom and are perfect for time-series plots)
• plots resize when windows are resized
• images support zoom and pan
• image lists are rendered as one image to speed up loading
• windows remember their positions
• implementation not relying on the filesystem, supports remote clients (sources)

Installation and usage

Install for Torch via:

luarocks install https://raw.githubusercontent.com/szym/display/master/display-scm-0.rockspec

Install for Python (numpy required) via:

python setup.py install [--user]

Launch the server:

th -ldisplay.start [port [hostname]]

Note, there is no authentication so don't use "as is" for sensitive data. By default, the server listens on localhost. Pass 0.0.0.0 to allow external connections on any interface.

See example.lua or example.py for sample usage.

disp = require 'display'
disp.image(image.lena())
disp.plot(torch.cat(torch.linspace(0, 10, 10), torch.randn(10), 2))

Supported commands

Common parameters:

• win: identifier of the window to be reused (pick a random one if you want a new window)
• title: title for the window title bar

image creates a zoomable <img> element

• src: URL for the <img> element
• width: initial width in pixels
• labels: array of 3-element arrays [ x, y, text ], where x, y are the coordinates (0, 0) is top-left, (1, 1) is bottom-right; text is the label content

plot creates a Dygraph, all Dygraph options are supported

• file: see Dygraph data formats for supported formats
• labels: list of strings, first element is the X label

text sends raw HTML

Technical overview

The server is a trivial message forwarder:

POST /events -> EventSource('/events')

The Lua client sends JSON commands directly to the server. The browser script interprets these commands, e.g.

{ command: 'image', src: 'data:image/png;base64,....', title: 'lena' }