##Infrared compositing## If you have [near-infrared imagery](/tool/near-infrared-camera) you can composite that imagery with the visible-light imagery to see how healthy the vegetation is. * [NDVI and NRG compositing](/wiki/ndvi) * [Video: Creating infrared composites of aerial wetlands imagery](https://www.youtube.com/watch?feature=player_embedded&v=pv6xB0y-rX4) - Learn to combine infrared and visible-light photographs (taken from balloon photography) to produce an "NRG" composite, where reddish color indicates photosynthesis. * [Video: Creating false-color NDVI with aerial wetlands imagery](https://www.youtube.com/watch?v=-nNnWEHNO_w) - Learn to use the open-source GIMP application to create a Normalized Differential Vegetation Index image from infrared and visible-light aerial photographs. Also explore false-color techniques for presenting the data. ##Contrast adjustments## Stretch the contrast and saturation of your images to see more detail, especially underwater. Read more here: * http://publiclaboratory.org/notes/warren/10-25-2011/using-colorcontrast-enhancement-see-water-aerial-photos ###Decorrelation stretching### _Nathan Craig writes:_ Decorrelation stretching may be a method to consider. Various flavors of the transformation are easily run using the DStretch Plugin for Image J. Several that seemed to represent variability relevant to the case study are included. I use DStretch to help bring out detail in rock art scenes that are highly eroded. However, the method has utility outside of rock art studies. It may be an additional approach to consider when trying to identify pollution or other contaminants. Here is information on DStretch http://www.dstretch.com/ Here is a paper that describes the transformation http://eospso.gsfc.nasa.gov/eos_homepage/for_scientists/atbd/docs/ASTER/atbd-ast-06.pdf [Browse more of these](https://www.flickr.com/photos/publiclaboratory/sets/72157627992773600/detail/) ##Classification## Using the ratios of Red, Green, and Blue (and possibly Near-infrared), spectral classification attempts to categorize regions of an image by land type. ###Read more on the [classification page »](/wiki/classification)### ### Image Analysis [activities:image-analysis]...
| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| utobolearning | "This is totally new topic for me. I am learning lot of things so this is also the New. utobo " | Read more » | about 4 years ago | |||
| warren | "Hi, you can use this simpler sequence for that: https://sequencer.publiclab.org/examples/#steps=ndvi,colormap This will just apply NDVI and the c..." | Read more » | almost 5 years ago | |||
| ThomasTaufan | "how to process single multispectral image with the modified webcam and red filter? Because when I saw your example, it is processing 2 images that ..." | Read more » | almost 5 years ago | |||
| cheneyshreve | ":smiley: " | Read more » | over 6 years ago | |||
| warren | "Just a note to self - as we plan out auto-registration features for this, could be good to look at #image-registration ! " | Read more » | over 6 years ago | |||
| warren | "Cool! We've tested blue filters with Raspberry Pi cameras, and it works well although the separate camera technique does result in cleaner separati..." | Read more » | over 6 years ago | |||
| xose | "During the leptos development we bought this board. We'are now playing with a point and shoot NDVI with raspi. I'll give the "IVMECH" board a chanc..." | Read more » | over 6 years ago | |||
| tech4gt | "This is so cool @warren " | Read more » | over 6 years ago | |||
| warren | "@imvec @xose too! " | Read more » | over 6 years ago | |||
| warren | "@tech4gt @ccpandhare check it out! :-) " | Read more » | over 6 years ago | |||
| liz | "true - images of melting ice was used by community members as "thermal clues" when searching for unknown/undocumented inflows into the canal. " | Read more » | over 9 years ago | |||
| warren | "There may have been confusion in part because some of the winter images GLAM took show trails where inflows melted ice, whether due to the flow of ..." | Read more » | over 9 years ago | |||
| gretchengehrke | "Ecta64, that's a good point. Liz confirmed that they never used thermal imaging system on the Gowanus, so it must have been a miscommunication abo..." | Read more » | over 9 years ago | |||
| gretchengehrke | "Hi Chris, Edan, whom I interviewed for this, was pretty adamant that the photos he saw and used were thermal images. I know specific kinds of came..." | Read more » | over 9 years ago | |||
| cfastie | "Gretchen, It's not just these particular photos, the Public Lab infrared cameras do not record thermal information. They are all near infrared came..." | Read more » | over 9 years ago | |||
| gretchengehrke | "Hi Chris, Thanks for the note! Good point -- I did not link to a thermal image there, nor use one for the lead image. I will sort through MapKnit..." | Read more » | over 9 years ago | |||
| cfastie | "Hi Gretchen, The Public Lab infrared images you refer to here are not thermal images. The near infrared photos don't have any information about tem..." | Read more » | over 9 years ago | |||
| liz | "new announcement: Landsat 8 data is available for anyone to use via Amazon S3. http://aws.amazon.com/public-data-sets/landsat/ " | Read more » | over 9 years ago | |||
| nicholas | "yahoo!!!!! I'm going to give this a go and will write a research note on the outcomes... " | Read more » | about 10 years ago | |||
| liz | "API for downloading LANDSAT from friends at Development Seed! http://www.developmentseed.org/blog/2014/08/29/landsat-util/ @nicholas @lprashad " | Read more » | about 10 years ago | |||
| davidmanthos | "I don't know enough about Google Earth Engine, but they are working on ways to make Landsat imagery, or at least 8-day composites, more accessible ..." | Read more » | over 10 years ago | |||
| liz | "also see @nedhorning 's online LANDSAT recipe demo: http://biodiversityinformatics.amnh.org/interactives/bandcombination.php " | Read more » | over 10 years ago | |||
| warren | "I was wondering if @davidmanthos knows a bit about how to access this in an easier way - David, is there a way to get a TMS or even WMS of the Land..." | Read more » | over 10 years ago | |||
| nicholas | "This is fantastic!!! Are there ways to automate downloads from the glovis website instead of going to the website each time? And it was mentioned..." | Read more » | over 10 years ago |