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|WATERCHESTNUTS||3 months ago by warren||44||11,766||85|
|Infragram||3 months ago by warren||93||71,884||11|
|Infragram convertible cameras||4 months ago by jenjimah||85||52,403||5|
|White balance for NDVI cameras||about 1 year ago by cfastie||10||9,980||2|
|NDVI from the PLOTS near infrared camera||over 1 year ago by cfastie||35||38,469||2|
|Infragram Sandbox||almost 2 years ago by liz||6||16,436||2|
|Public Lab Lesson 3: Photography in a New Light||about 2 years ago by gretchengehrke||15||6,705||5|
|Idea:80%COMPLETED-SAP project (Smart Agriculture Payload)||about 2 years ago by Mohamed||3||4,443||1|
|Infragram FAQ||about 2 years ago by ShintoSunrise||33||12,730||2|
|Interpreting infrared images||over 2 years ago by aguchosolano||4||4,486||0|
|Photo Monitoring Plugin||almost 3 years ago by cfastie||12||20,234||7|
|Infragram Webapp Dev||almost 3 years ago by NickJemis||35||9,303||1|
|ndvi-gradients||almost 3 years ago by cfastie||5||8,097||3|
|LEAFFEST 2013||almost 3 years ago by cfastie||59||11,475||2|
|Infragram Media||about 3 years ago by warren||51||20,182||3|
|Camera Selection||over 3 years ago by hagitkeysar||18||18,565||12|
|Dual Camera Kit Guide||over 3 years ago by cfastie||24||17,724||0|
|Dual Camera Kit Software||over 3 years ago by cfastie||24||11,021||0|
|GoPro||about 4 years ago by gonzoearth||10||13,734||5|
|Near Infrared Camera history||about 4 years ago by warren||3||10,048||0|
|iFarm 2013||about 4 years ago by cfastie||23||8,508||1|
|Near infrared imaging||over 4 years ago by liz||11||10,509||1|
|LeafKam||over 4 years ago by cfastie||13||3,819||1|
|IRCam||over 4 years ago by warren||17||8,091||2|
|T-bracket Dual Camera Rig||almost 5 years ago by mathew||11||8,635||0|
|Canon A495 Tips||almost 5 years ago by cfastie||14||9,534||12|
|GMF 2 infrared camera feature||about 5 years ago by mathew||13||8,542||0|
|Dual camera kit electronics||about 5 years ago by mathew||22||8,511||2|
|NIR proof of concept: Trout Lily||over 5 years ago by cfastie||1||5,572||0|
|Infrared Vegetation Analysis Activity||over 6 years ago by warren||5||9,377||0|
The Infragram Kickstarter video, a great introduction to the project.
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 (using 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 available in the Public Lab Store.
Multispectral or infrared/visible photography has seen a variety of applications in the decades since it was developed. We have focused on the following uses:
Notable uses include this photograph of an unidentified plume of material in the Gowanus Canal (and writeup by TechPresident) and a variety of projects at a small farm in New Hampshire at the annual iFarm event. The Louisiana Universities Marine Consortium has also collaborated with Public Lab contributors to measure wetlands loss 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:
Camera modification: We've worked on several different techniques, from dual camera systems to the current, single-camera technique. This involves removing the infrared-blocking filter from almost any digital camera, and adding a specific blue filter.
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. You can also learn more about how digital camera image sensors detect colors at this great tutorial by Bigshot.
Post-processing: 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. An in-depth article on the technique by Chris Fastie (albeit using red instead of blue for visible light) can be found here.
History of the project: While we used to use a two-camera system, research by Chris Fastie and other Public Lab contributors 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. You can use this filter to turn most webcams or cheap point-and-shoots into an infrared/visible camera.
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 and Vegscape -- but this imagery is not collected when, as often, or at useable scale for individuals who are managing small plots.
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
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(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:
Note: Older versions of this page have been kept at the following wiki page: http://publiclab.org/wiki/near-infrared-camera-history