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Multispectral imaging

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4,569 views | Last edited by warren about 3 years ago | #13341


The Public Lab near infrared imaging project is an open source community effort to modify consumer cameras to capture near infrared imagery for a range of purposes, including plant health. All open or accessible near infrared imaging hardware and software efforts are welcome here!

Join in by:

  • Reading about goals and asking great questions
  • Converting a camera using one of our starter kits
  • Trying (and critiquing) our community-made how-to guides
  • Posting your own how-to guides and mods
  • Building on others’ work; hack and remix the kits to refine and expand them
  • (proposed?) Submit your improvements for inclusion in an upcoming starter kit release or add-on
  • (proposed?) Serve on a Research Review Group for a 3 month period

Activities

This is a list of community-generated guides for specific applications using your near-infrared imaging setup (either a camera you converted yourself with a filter pack, a ready-made near-infrared camera, or double camera setup). Some may be more reproduced -- or reproducible -- than others. Try them out to build your skills, and help improve them by leaving comments. Together, we can repeat and refine the activities into experiments.

Purpose Category Status Author Time Difficulty Replications Goal
White-balance your camera; watch video category status @cfastie X m X 0 replications Try It X replications
Classroom activity to understand, capture, and analyze near-infrared images category status @mathew & Amanda Fisher 2.5 h X X replications Try It X replications
Compare cultivation methods in your garden category status @liz X m X 1 replications Try It X replications
Observing leaf pigments 1 category status @cfastie X m X 0 replications Try It X replications
Observing leaf pigments 2 category status @cfastie X m X X replications Try It X replications
Observing leaf pigments 3 category status @cfastie X m X X replications Try It X replications
Observing root pigments category status @cfastie X m X X replications Try It X replications
Observing fruit pigments (lycopene) category status @cfastie X m X X replications Try It X replications
Observing insect pigments (hornworms) category status @cfastie X m X X replications Try It X replications
Observing crop health 1 category status @cfastie X m X X replications Try It X replications
Observing crop health 2 category status @cfastie X m X X replications Try It X replications
Observing atmospheric refraction category status @cfastie X m X X replications Try It X replications
Observing atmospheric scattering category status @cfastie X m X X replications Try It X replications
Observing NIR absorption by water category status @cfastie X m X X replications Try It X replications
Comparing NIR absorption by beverages 1 category status @cfastie X m X X replications Try It X replications
Comparing NIR absorption by beverages 2 category status @cfastie X m X X replications Try It X replications
Comparing filters category status @cfastie X m X X replications Try It X replications

Add your guide here Request a guide

Guides should include a materials list and a step-by-step construction guide with photo documentation. See an example.


Hardware Mods

Have you added to your starter kit, improved it, or redesigned it? Show others how to take it to the next level by posting a build guide here:

Title | Author | Time | Difficulty | Status (?) | Goal ----------|----------|----------|----------|----------|----------|

Add your hardware modification here Request a hardware modification

Mods should include a parts list and a step-by-step construction guide with photo documentation. See an example.


Builds

There’s a lot going on in open source near-infrared imaging -- if you’ve developed another open source design you’d like to show others how to construct, post it here!

  • Rasberry Pi NoIR
  • X
  • XX

Choosing a tool / Starter Kits

The question to start with is whether you can capture all the channels you need for your research question with a single converted camera or whether you should use a dual camera rig with one converted camera and one unconverted. That choice plays out in terms of what filter (blue or red) to use for converting your camera.

Public Lab’s Kits initiative offers several starter kits, one with the basic components and instructions for converting your own digital camera to capture near-infrared imagery and a second option -- a readymade lightweight near-infrared camera. The point of the kits is to lower the barrier to capturing your own near-infrared imagery.

  • The Infragram filter pack is our least expensive way to get started with near-infrared imaging, but it does require an afternoon and some technical work to perform the camera conversion yourself. ... etc etc etc

Visit the Infragram DIY filter pack

  • The Infragram point and shoot is a Mobius camera that we worked with a factory to modify. ... etc etc etc

Visit the Infragram Point&Shoot page


Processing near-infrared imagery

Once you take a multispectral photograph with a modified camera, you must post-process it, compositing the infrared and visible data to generate a new image which (if it works) displays healthy, photosynthetically active areas as bright regions. In-depth articles on the technique by Chris Fastie can be found here:


Software

How to process your images: we're working on an easy process to generate composite, infrared + visible images that will reveal new details of plant health and photosynthesis. There are several approaches:


Comparison to standard tools

Infrared imagery for agricultural and ecological assessment is usually captured from satellites and planes, and the information is used mainly by large farms, vineyards, and academic research projects. For example, see this illustrated PDF, page 210 from a commercial imagery provider who has been studying the usefulness of infrared imagery and has quotes from farmers who make use of it. There are public sources of infrared photography for the US available through the Department of Agriculture -- NAIP and Vegscape -- but this imagery is not collected when, as often, or at useable scale for individuals who are managing small plots.


Frequently Asked Questions

Ask a question about multispectral-imaging

Title Author Updated Likes Comments
How to design a camera for calculating ENDVI. @nickyshen0306 2 months ago 5
Infragram Point and shoot photos: white balance not working @Muneeswaran 11 months ago 0
Is it possible to calculate average NDVI in a picture using infragram's sand box? @Hala73 over 1 year ago 6
Problem with filter for Raspberry Pi NoIR Camera @sjmanosalvas over 1 year ago 1
Spectral Range of Lens? @RexToother over 1 year ago 3
600 year old cedar tree - Infragram @Randall over 1 year ago 8
Visible Atmospherically Resistant Index (VARI) @rway almost 2 years ago 0
Can we use a color calibration reference card to calculate absolute values for DIY NDVI? @warren about 2 years ago 1
"Test images" for multispectral image processing @warren over 2 years ago 6
Can I use any red filter for capturing NIR light? @sujayj over 2 years ago 2
I would like to know why near infared imaging works, and what it does. @kiramac almost 3 years ago 1
Video Infragram @jfd almost 3 years ago 5
Identify Plastic Material Using Infrared Imaging @shaikhgous almost 3 years ago 1
Question infragram kit @marfisistemidroni about 3 years ago 5
What is the ideal white balance for the Infragam Point and Shoot? @abdul about 3 years ago 1
Can anyone help me troubleshoot my NDVI imagery? @abdul about 3 years ago 6
How to process images using a mobius with an IR lens? @miguel_rosas about 3 years ago 1
MobiusActionCam vs S100 @ashwinvasudevan about 3 years ago 5
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