Colormaps are used to show details in monochrome (greyscale) images, by showing pixel intensity values using a wide range of colors instead of just from black => white. This makes finer details easier to see, although it may make it harder for colorblind viewers to read depending on the colors chosen. See https://publiclab.org/ndvi-gradients for a collection of common and useful colormaps by @cfastie. Some colormaps are not linear, meaning they use a set of color changes in one region of the scale to emphasize features with approximately that brightness. Colormaps are also known as "lookup tables" or LUTs, and the process overall is sometimes known as "false color" (alongside other color compositing techniques). Learn more in these posts: [notes:grid:colormap]...
| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| warren | "I believe that if Cindy had pressed Fastie colormap instead of step 3, she would have gotten the same result as Chris's first image -- perhaps a sl..." | Read more » | almost 9 years ago | |||
| cfastie | "I can't help much with the infragram.org process. It seems to be pretty easy to produce an image that doesn't have any obvious relationship to the ..." | Read more » | almost 9 years ago | |||
| warren | "So I wonder if we should not show the colorize button until you press "run"? Is there any situation where you'd want to colorize before pressing ru..." | Read more » | almost 9 years ago | |||
| warren | "Hi, Cindy - let me try to follow your steps and note what I think you've done in each one. Note that if you think one step is really not intuitive,..." | Read more » | almost 9 years ago | |||
| mathew | "I was having trouble getting the white balance settings to load. figured it out from a manual editing page on RC groups: http://www.rcgroups.com/fo..." | Read more » | about 10 years ago | |||
| cfastie | "Thanks, download works! Mathew, The white balance settings for both of your Mobius shots at infragram.org are 288, 256, 432. That suggests the came..." | Read more » | about 10 years ago | |||
| warren | "Added! " | Read more » | about 10 years ago | |||
| warren | "Ah, good call. There are a zillion features we need to add to Infragram, but I think i can add that one reasonably fast. Let me try. " | Read more » | about 10 years ago | |||
| cfastie | "I couldn't find a way to download Mathew's original Infragram from Infragram.org. Is there a way? All I could get was the result image. " | Read more » | about 10 years ago | |||
| mathew | "sure image is here. " | Read more » | about 10 years ago | |||
| warren | "Yeah that doesn't look like it's working at all -- can you link to your Infragrammar.org image so I can try to debug? " | Read more » | about 10 years ago | |||
| mathew | "This formula doesn't produce anything like NDVI for me. I always get an image that looks the same as unprocessed, with some artifacting. " | Read more » | about 10 years ago | |||
| warren | "As i pointed out in the comments here yesterday, this HSV approach is pretty interesting and conceptually fun, but not ideal for real work with LUT..." | Read more » | about 10 years ago | |||
| mathew | "This isn't working for me either. I get a red or blue image, but not a NDVI-style color map. " | Read more » | about 10 years ago | |||
| cfastie | "The infrablue photos from the camera for this scene is here: http://publiclab.org/notes/warren/05-27-2013/infragram-test-photos-from-a-plane-window " | Read more » | over 10 years ago | |||
| bc512 | "I would love to see the raw image of this if possible? what setup are you using etc? thank you " | Read more » | over 10 years ago | |||
| warren | "Is this when you press the "run" button? Can you post which version of Chrome and which OS, and which expression you were using in Infragrammar? Ho..." | Read more » | over 10 years ago | |||
| bc512 | "Unfotunately this isnt working for me, it just fails and the chrome page does the "oh snap" thing :( " | Read more » | over 10 years ago | |||
| cfastie | "Those are nice sharp airplane window shots. I made NBG false color infrared from them and added them to the Infrafilters posts: http://publiclab.or..." | Read more » | almost 11 years ago | |||
| gonzoearth | "these are great! " | Read more » | almost 11 years ago |