lfp-viewer

lfp-viewer decodes Lytro LFP files in JavaScript, suitable for use in a web browser.

This project is not affiliated with Lytro, or any of the current holders of Lytro assets.

Lytro? LFP File?

Lytro was a company that made weird "light-field" cameras for consumer use. Their big thing is that they don't capture a single image plane, but also some information about the directionality of light to allow some refocusing based solely on captured data. How much refocusing? See https://bkerley.github.io/lfp-viewer/ (scroll down)

As far as I know, they released an original rectangular prism-shaped camera, a much larger "Illum" one shaped like a more traditional camera, started work on a bigger camera, and then shut down forever.

My Illum shoots two kinds of file by default:

• a .LFR file that's over 50mb and presumably contains the raw sensor data, intended for further processing or archiving

• a .LFP file that's under 1mb and contains ten JPEGs and some other metadata, which was seemingly intended for sharing

This project decodes the .LFP files, because it's easy :P

Just Looking

Check out https://bkerley.github.io/lfp-viewer/ , or index.html in this directory.

I want this on my own web page

Download the lfp-viewer.js file from https://bkerley.github.io/lfp-viewer/ and put it in a script tag; at the very bottom of the page works fine.

Right now it looks for any instances of HTML elements like <lfp-debug src="demo/demo.LFP"></lfp-debug>, replaces them with a <lfp-debug-info> element full of info, including image blobs waaaayyyy at the bottom.

I want to hack on this

Cool!

This project uses TypeScript, which means you're gonna have to deal with getting these installed:

1. node and npm (pretty sure i just did brew install npm)
2. dependencies (npm install from the project root)

Once you've got that up and running, I tend to keep npx run dev-server going while I'm typing, and just mash reload in the web browser to see changes.

Things I'd like to do

• actually successfully decode images from a file
• make a lfp-viewer tag that doesn't do all the debug info
• write a script to animate lfp-viewer stuff?
• Dockerfile for dev work

References and Resources

I found these references useful. Their authors aren't affiliated with this project.

Lytro Meltdown by Jan Kučera was a great read to help me get this project going. The "File Format" page especially!

lfptools by Syoyo Fujita was really useful to help me understand this was a possible and easy thing to do. Running a simple C program and watching JPEGs fall out was awesome.

Reverse Engineering the Lytro LFP File Format by Nirav Patel is inspiring too, and may be useful for a future phase of this project???

Contact

Bryce Kerley

Email: mailto:bkerley@brycekerley.net

Mastodon: https://m.bonzoesc.net/@bonzoesc