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Multispectral imaging

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. [activities:multispectral-imaging] 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: [upgrades:multispectral-imaging] Add your hardware modification here Request a hardware modification _Upgrades 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](/wiki/infragram-point-shoot)** **** ## 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: * The **easiest way** is to process your images online at the free, open source []( * [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) * Command-line processing of single images and rendering of movies using a Python script: Source code is [here]( and here: [here]( * For those who use the webcam and have a Python interpreter, there are some image processing codes available at [Python Webcam Codes](/wiki/python-webcam-codes) * Using (deprecated) **** ## 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 Get notified of new questions and help out [notes:question:multispectral-imaging] ...

Author Comment Last activity Moderation
warren "Hi, Ned - do you think you could post the original images from which you generated your NDVI? Thanks! " | Read more » over 6 years ago
jfd "Nice! Thank you Warren, ok I will check it out. Yes, I will develop on Github... I will have some time in next 2 weeks, once I get a prototype goin..." | Read more » almost 7 years ago
warren "Are you developing on GitHub, and might I follow your progress there? " | Read more » almost 7 years ago
warren "Well, basically we just take the incoming image pixel by pixel, and for each of the input pixels, we plug their color values into the "infragrammar..." | Read more » almost 7 years ago
jfd "Hi Warren, Thank you for your email; I see this is a greenfield area. I'd like to get this implementation to run as fast as possible. If you could..." | Read more » almost 7 years ago
warren "Hi, this is a good question, but I wanted to suggest possibly adapting the WebGL implementation which is awfully fast:" | Read more » almost 7 years ago
suman "i want to buy DYI plant health analyzer filter......i tried to buy from public labs but it's already out of stock. How can i possibly buy it for in..." | Read more » almost 7 years ago
azaelb "Thanks warren, I got these cameras from Amazon, vendor digital_family, product ASIN B01FLVPZNY. It is now under $60. On pictures I just had some pi..." | Read more » almost 7 years ago
warren "Also do you have any pics you took with the camera to share? Raw and NDVI for comparison? Thank you!!! " | Read more » almost 7 years ago
warren "Wow, amazing -- do you have a link to where you can buy this camera, and any data on how much it weighs? It could be a great alternative for people..." | Read more » almost 7 years ago
nedhorning "Hi kaushalsingh – The three target reflectance values you note seem like a good choice to me. At this point I do not have study material in additi..." | Read more » almost 7 years ago
kaushalsingh "@nedhorning You got it right Ned. I am trying to calibrate the image using a reference target before you calculate NDVI. Suppose, I have 3 target ..." | Read more » almost 7 years ago
nedhorning "Hi kaushalsingh – Ait seems as if you are trying to calibrate the image using a reference target before you calculate NDVI? If that assumption is a..." | Read more » almost 7 years ago
kaushalsingh "@nedhorning Hello Ned, I have calculated ndvi using following code in matlab, using single camera without white balancing: red_orig = imread('IM..." | Read more » almost 7 years ago
cfastie "Mario, After the internal filter has been removed, a new filter can be used either inside the camera or in front of the lens. It's hard to keep the..." | Read more » almost 7 years ago
marfisistemidroni "Where can I send pictures? " | Read more » almost 7 years ago
marfisistemidroni "Hi Chris, thanks for the reply. The kit "DIY Plant Analysis Filter Kit" consists of a red and a blue gelatin. Yes, I want to change the Phantom cam..." | Read more » almost 7 years ago
cfastie "I need some help with your questions. What is the name of the product you bought from Public Lab? Do you want to modify the camera on your DJI Pha..." | Read more » almost 7 years ago
Claytonb "@Thorsten I have not tried using a chart like the color checker though I have used materials(plastic, felt, paper) in the shade of red on the chart..." | Read more » almost 7 years ago
Thorsten "@Claytonb great work as usual! Two questions: Have you tried some reddish colors of calibration targets such as the ColorChecker? http://xriteph..." | Read more » almost 7 years ago
warren "Wow, this is super impressive!!! " | Read more » about 7 years ago
cfastie "This is a great discovery. It will be good to learn how this color works with a red filter like Wratten 25. I will keep my eye out for Boom Chicka ..." | Read more » about 7 years ago
nedhorning "The image for this note with the blue color was probably a JPEG image white balanced using red paper. The raw image will have much higher values in..." | Read more » about 8 years ago
agustin_castellano "Thanks Ned. I have a red filter (600nm) and the filter color is red and the pictures that i take with this filter are red why you have a similar fi..." | Read more » about 8 years ago