Comments

Author Comment Last activity Moderation
cfastie "It looks like the computed index will no longer be between -1 and +1 if you adjust the red value that way. Do you then have to rescale the index so..." | Read more » over 9 years ago
cfastie "Oh and the controller (SkyShield plus Nano) should have Velcro loops underneath to match hooks on the top of the frame. I think I included a second..." | Read more » over 9 years ago
cfastie "Excellent progress. Everything looks good. The Picavet shaft should be tight so it does not slip. Once it is in place, there is not much reason to ..." | Read more » over 9 years ago
cfastie "For an S100, the center of the tripod screw hole should be 5.3 cm from the close end of the camera tray (the end that attaches to the servo). That'..." | Read more » over 9 years ago
cfastie "Wow, USPS is fast. It looks like you already did a little assembly. How hard was it to screw on the orange leg brackets? And you added a camera! So..." | Read more » over 9 years ago
cfastie "Hi Tgran, I agree that we are probably reinventing the wheel. There seems to be a huge range of comfort with this type of simple electronics, So p..." | Read more » over 9 years ago
cfastie "That's pretty gutsy flying right there in the hood. Very impressive. The default mode (Mode 0) has eight pan positions. The A495 needs more than t..." | Read more » over 9 years ago
cfastie "Nice mosaics. Where are you flying from? The street? I don't see any park nearby. Which mode were you using? it looks like there might not be enou..." | Read more » over 9 years ago
cfastie "For a photos from a red-filtered camera like the bluish photo above, in the Photo Monitoring plugin select the red channel to represent red and the..." | Read more » over 9 years ago
cfastie "Nice mosaics. The color images seem to have a typical range of colors. These look like good results. Can you explain why you were expecting someth..." | Read more » over 9 years ago
cfastie "Oh, that's what's happening. I wondered how it worked at all in Chrome without Silverlight support. In all other browsers you see overlays of zooma..." | Read more » over 9 years ago
cfastie "RQ, The white balance looks good. I think those are the settings used by Public Lab. But experimenting with similar numbers could produce better r..." | Read more » over 9 years ago
cfastie "In a sense these sensors all have zero lag. As soon as the the materials that make up the sensor reach ambient temperature, the sensor will tell yo..." | Read more » over 9 years ago
cfastie "Yikes. You never did like Picavets did you? I can see that the relationship is not moving in a positive direction. One of you two needs to start sh..." | Read more » over 9 years ago
cfastie "I found that image in Googleland, I'm not sure where. Wikipedia has a complete article with lots of references: http://en.wikipedia.org/wiki/Sunlight " | Read more » over 9 years ago
cfastie "@fgiorlando, I assume the Hoya 25A filters are just as good as Wratten 25A filters for infrared photography. The Hoya glass filters would produce c..." | Read more » over 9 years ago
cfastie "There seems to be a lot of marketing hooey at the Agribotix site. They seem to be doing DIY uncalibrated infrared vegetation index work like a lot ..." | Read more » over 9 years ago
cfastie "The angle from which the photo is taken and the angle of the sun do influence the NDVI result. NDVI values are a function of how much red and NIR l..." | Read more » over 9 years ago
cfastie "Stretching the histograms of either the NIR or VIS (or both) channels used to make NDVI is a trick that can produce more meaningful NDVI. I don't k..." | Read more » over 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 » over 9 years ago
cfastie "Excellent @patcoyle. I'll ship it tomorrow. Do you know which camera you are likely to use on it? " | Read more » over 9 years ago
cfastie "A standard coefficient is a tough nut. The amount you would want to shift the NDVI values will differ a lot among photos. Exposure and color balanc..." | Read more » over 9 years ago
cfastie "Yes, I can't say much without seeing the originals. Someone familiar with what infragram.org does might be able to infer something. When I follow ..." | Read more » over 9 years ago
cfastie "That looks like a photo taken with a red filtered infrared camera. It is very hard to get meaningful NDVI results directly from this photo because ..." | Read more » over 9 years ago