Near-Infrared Camera
near-infrared-camera

_The Infragram Kickstarter video, a great introduction to the project._ ###Introduction Vineyards, large farms, and NASA all use **near-infrared photography** for assessing plant health, usually by mounting expensive sensors on airplanes and satellites. At Public Lab, **we've developed a Do-It-Yourself way to take these kinds of photos**, enabling us to monitor our environment through quantifiable data. Our technique uses a modified digital camera to capture near-infrared and blue light in the same image, but in different color channels. We then [post-process the image](#How+to+process+your+images:) (using [Infragram.org](http://infragram.org)) to attempt to infer how much it is photosynthesizing. This allows us to better understand and quantify how much of the available light plants are metabolizing into sugar via photosynthesis. > You can do this yourself (as with all Public Lab tools) but there is also an [Infragram DIY Filter Pack](http://store.publiclab.org/products/infragram-diy-filter-pack) available in the Public Lab Store. We [ran a Kickstarter](http://kickstarter.com/projects/publiclab/infragram-the-infrared-photography-project/) for a version of this camera we call the **Infragram**. [Read more about it here »](/wiki/infragram) Here's the video from the Kickstarter, which offers a nice visual explanation of the technique: ###What is it good for? Multispectral or infrared/visible photography has seen a variety of applications in the decades [since it was developed](#Background:+satellite+infrared+imaging). We have focused on the following uses: - Take pictures to examine plant health in backyard gardens, farms, parks, and nearby wetlands - Monitor your household plants - Teach students about plant growth and photosynthesis - Create exciting science fair projects - Generate verifiable, open environmental data - Check progress of environmental restoration projects - Document unhealthy areas of your local ecology (for instance, algal blooms) Notable uses include [this photograph of an unidentified plume of material in the Gowanus Canal](/notes/liz/8-3-2011/infrared-balloon-image-reveals-gowanus-plume) (and [writeup by TechPresident](http://techpresident.com/blog-entry/how-diy-science-solving-ecological-mysteries-new-york-city)) and a variety of projects at a small farm in New Hampshire [at the annual iFarm event](/tag/ifarm). The [Louisiana Universities Marine Consortium](http://lumcon.edu) has also [collaborated with Public Lab contributors to measure wetlands loss](/notes/shannon/5-29-2011/plots-and-lumcon-collaboration) following the Deepwater Horizon oil disaster. **Here's an example** of what one of our "Infragram" cameras sees (left) and the post-processing analysis which shows photosynthetic activity, or plant health (right). This picture was taken from a commercial airplane flight: [![infragram](https://i.publiclab.org/system/images/photos/000/000/424/medium/aerial-split.jpg)](https://i.publiclab.org/system/images/photos/000/000/424/original/aerial-split.jpg) ###How does it work? **Camera modification:** We've worked on several different techniques, from [dual camera systems](/wiki/dual-camera-kit-guide) to the current, single-camera technique. This involves removing the infrared-blocking filter from [almost any digital camera](/tag/infragram-conversion), and adding a [specific blue filter](/wiki/infragram#Filters). ![swap.png](https://i.publiclab.org/system/images/photos/000/000/376/medium/swap.png) This filters out the red light, and **measures infrared light in its place** using a piece of carefully chosen "NGB" or "infrablue" filter. Read more about [the development of this technique here](http://publiclab.org/notes/cfastie/04-20-2013/superblue). You can also learn more about how digital camera image sensors detect colors [at this great tutorial by Bigshot](http://www.bigshotcamera.com/learn/image-sensor/index). **Post-processing:** Once you take a multispectral photograph with a modified camera, you must [post-process it](#How+to+process+your+images:), compositing the infrared and visible data to generate a new image which (if it works) displays healthy, photosynthetically active areas as bright regions. An in-depth article on the technique by Chris Fastie (albeit using red instead of blue for visible light) [can be found here](/wiki/ndvi-plots-ir-camera-kit). **History of the project:** While we used to use a two-camera system, [research by Chris Fastie](/notes/cfastie/04-20-2013/superblue) and [other Public Lab contributors](/tag/near-infrared-camera) have led to the use of a **single camera which can image in both infrared and visible light simultaneously**. The Infrablue filter is just a piece of carefully chosen theater gel which was examined using [a DIY spectrometer](/wiki/spectrometer). You can use this filter to turn most webcams or cheap point-and-shoots into an infrared/visible camera. ###Background: satellite infrared imaging The study of Earth's environment from space got its start in 1972 when the first Landsat satellite was launched. The multispectral scanner it carried, like the scanners on all subsequent Landsat satellites, recorded images with both visible and near infrared light. Remote sensing "scientists" quickly learned that by combining visible and infrared data, they could reveal critical information about the health of vegetation. For example, the normalized difference vegetation index (NDVI) highlights the difference between the red and infrared wavelengths that are reflected from vegetation. Because red light is used by plants for photosynthesis but infrared light is not, NDVI allows "scientists" to estimate the amount of healthy foliage in every satellite image. Thousands of "scientists", including landscape ecologists, global change biologists, and habitat specialists have relied on these valuable satellite-based NDVI images for decades. There are public sources of infrared photography for the US available through the Department of Agriculture -- [NAIP](http://datagateway.nrcs.usda.gov/) and [Vegscape](http://nassgeodata.gmu.edu/VegScape/) -- but this imagery is not collected when, as often, or at useable scale for individuals who are managing small plots. ![ndvi-vis-comparison.jpg](/system/images/photos/000/001/289/medium/ndvi-vis-comparison.jpg) Caption: Normal color photo (top) and normalized difference vegetation index (NDVI) image. NDVI image was derived from two color channels in a single photo taken with a camera modified with a special infrared filter. Note that tree trunks, brown grass, and rocks have very low NDVI values because they are not photosynthetic. Healthy plants typically have NDVI values between 0.1 and 0.9. Images by Chris Fastie. Visit the [gallery of high-res images by Chris Fastie](https://plus.google.com/photos/116103622078305917397/albums/5878196749239180465/5878198341400814034) **** ## Frequently Asked Questions Ask a question about infrared imaging [notes:question:infragram] **** ## How to process your images (this section is moved to and updated at http://publiclab.org/wiki/near-infrared-imaging) 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: * The **easiest way** is to process your images online at the free, open source [Infragram.org](http://infragram.org) * [Ned Horning's](/profile/nedhorning) [PhotoMonitoring plugin](/wiki/photo-monitoring-plugin) * Manual processing * [in Photoshop](/notes/warren/10-25-2011/video-tutorial-creating-infrared-composites-aerial-wetlands-imagery) * [or GIMP](/notes/warren/10-27-2011/video-tutorial-creating-false-color-ndvi-aerial-wetlands-imagery) * Using MapKnitter.org (deprecated) * Command-line processing of single images and rendering of movies using a Python script. Source code is [here](https://github.com/Pioneer-Valley-Open-Science/infrapix) **Note:** Older versions of this page have been kept at the following wiki page: http://publiclab.org/wiki/near-infrared-camera-history...


Author Comment Last activity Moderation
Gianni_Gadaleta "Good evening @AFairbairn , I read with great interest your post because even I and my group are having the same difficulties to develop good NDVI i..." | Read more » over 8 years ago
Caca_nkg "Hi guys... Any success with the Phantom??? " | Read more » over 8 years ago
cfastie "I like #4 too. I don't have a good answer for the type of glue. Something thick and quick drying. It does not have to be sticky, it just has to for..." | Read more » over 8 years ago
talha "Thank you very much for your quick and informative answer, Mr. Chris. Among those choices, which one do you suggest? To me, #4 looks ideal (light c..." | Read more » over 8 years ago
cfastie "The new filter can be put several different places: stick it on the front of the lens. Build a frame to hold it in front of the lens: https://pub..." | Read more » over 8 years ago
talha "I'm getting crazy, there is massive amount of talk about mobius conversions but there is no single guidance for converting the mobius for ndvi. I'v..." | Read more » over 8 years ago
Matthew318 "Using a heat gun allowed a clean removal of the filter, much easier than smashing. Would recommend just getting a $20 heat gun from home depot. " | Read more » over 8 years ago
Claytonb "@AFairbairn - I spent quite some time searching for reliable and cheap target material for calibrations. I spoke with someone who scanned Rustoleum..." | Read more » over 8 years ago
cfastie "Yes I have seen Valspar in the US for many years, and Rustoleum is a big brand here. Maybe there is some international brand of art supplies that m..." | Read more » over 8 years ago
AFairbairn "Good points. I am checking if my University has a spectrometer, I do not think my department does, however our geology people may have one. Waiting..." | Read more » over 8 years ago
cfastie "Any place that sells paint has paint color chips, but these are too small to be useful as targets. But fancy paint stores have huge color samples. ..." | Read more » over 8 years ago
cfastie "That's a really relevant article. They scale the graphs relative to a standard, so 100% is actually 20% reflectance. That means 25% reflectance of ..." | Read more » over 8 years ago
AFairbairn "Chris, You are probably correct about the foil being a poor material because of how shiny it is, had not really considered that. I came across thi..." | Read more » over 8 years ago
cfastie "ISO 100, 1/320 shutter speed That is much better than I thought would be possible. I don't know how those skinny little bands provide enough light..." | Read more » over 8 years ago
AFairbairn "Jut did a really crude test, the image displays as it should, green in the cracks, green algae or whatever it is on the fence. The small panel in f..." | Read more » over 8 years ago
AFairbairn "Chris, Thank you again for all the great information. I would assume the filter you found on PeauProductions website is the one in the lens I purch..." | Read more » over 8 years ago
cfastie "Ned listed some resources of spectral reflectance data of common things in this note: https://publiclab.org/notes/nedhorning/11-01-2013/why-a-red-f..." | Read more » over 8 years ago
cfastie "PeauProductions has this filter here: This must be a dichroic filter. The narrow bands could produce good results. We don't know how much cross ..." | Read more » over 8 years ago
AFairbairn "Chris, Thank you for your comments. I realize I should have provided a bit more information. Unfortunately a multispectral imager was not in my bu..." | Read more » over 8 years ago
cfastie "It would be good to know something about the camera and filter you are using. Do you have a spectral curve for the filter? How is the camera white ..." | Read more » over 8 years ago
DFlores6073 "I use Fiji with the photomonitoring plugin...I would like to create a legend with the values, what would be AWSOME is to have the values on the ima..." | Read more » almost 9 years ago
jtuhtan "Hi David, The code I used was MATLAB, overlaying an image of the Fastie colormap onto the NDVI image. What software are you working with? " | Read more » almost 9 years ago
DFlores6073 "Jeff (Jtuhtan) could you please direct me to the right place so I can create a legend with values on my NDVI photos... Thank You David " | Read more » almost 9 years ago
nedhorning "A good way to get feedback about processing your infrared photos is to post the question with a sample image to the Public Labs Infrared Google Gro..." | Read more » almost 9 years ago