gain-correction
gain-correction


Author Comment Last activity Moderation
warren "Some serious progress has been made on this, for running SpectralWorkbench on the Raspberry Pi and connecting to it's camera: https://github.com/pu..." | Read more » over 3 years ago
raj "raspberry pi camera: spectral response curves for more details go through my website you can get all details http://zipansion.com/1TSg4 " | Read more » almost 4 years ago
stoft "Ah, good. Glad you could view the additional data and figured it out. " | Read more » over 4 years ago
Tehnicni "How a stupid mistake. I checked linearity of all 3 cameras at three points, thinking that it have an exponential dependency, which is not true, the..." | Read more » over 4 years ago
stoft "Yes, clearly all but the last image shows compression in the Green (and Red though less). Because the process of spectral data from a webcam does n..." | Read more » over 4 years ago
Tehnicni "I also tried the third webcam, cheap Chinese. White Balance: R and G at max, B in the middle. Gama 2, Exposuer manually Measured at different..." | Read more » over 4 years ago
stoft "The camera's I've used seem different in this effect but you might try to hunt down the technical data sheets from the Mfg -- sometimes they have a..." | Read more » over 4 years ago
Tehnicni "I'm using wery old cheap webcam with all controll on manual and get same result with Logitech C525 also in manual mode. I checked lineariti on all ..." | Read more » over 4 years ago
stoft "@Tehnicni, I'd agree that any detector-specific non-linearity is likely very small compared with the effect you've presented. I'd guess the more li..." | Read more » over 4 years ago
Tehnicni "Question for @stoft. According to my measurements, the CMOS sensor has some sort of blooming effect before saturation. I tested my webcam with whit..." | Read more » over 4 years ago
warren "Just wanted also to link to @stoft's input on this question in this comment: As to the RPi camera, it seems to have two "difficulties" which need ..." | Read more » over 5 years ago
warren "Oh great; @khufkens also shared that on this site! https://publiclab.org/notes/khufkens/11-02-2015/ov5647-raspberry-pi-camera-spectral-response-qua..." | Read more » over 5 years ago
warren "I found that V4L2 driver apparently makes it possible to use the raspberry pi camera in Firefox with webrtc, the API Spectral Workbench uses: https..." | Read more » over 5 years ago
Siphirobe "I was wondering the same thing, just with the PiNoIR camera since I am more interested in remote sensing of vegetation. " | Read more » over 5 years ago
stef "@warren After sleeping it over, realized that due to the no IR filter of the raspberry the bandwidth response will be different from the published..." | Read more » over 5 years ago
stef "@warren Here is a link http://www.khufkens.com/projects/ov5647-spectral-response/ and here is a zip file khufkens-pi-camera-response-curves-3342e..." | Read more » over 5 years ago
warren "That's a great thing to point out -- do you per chance have a link to the spectral bandwidth of the sensors? Thanks! " | Read more » over 5 years ago
stef "The BIG advantage of the Raspberry Pi is the use of the Sony IMX298 sensor whose spectral bandwidth is known and is 16 megapixel sensor. Much like ..." | Read more » over 5 years ago
stoft "Great! Yes, little glitches do creep in but yes, this Solux corrected plot has a much better shape. I'm guessing the slight curve variation between..." | Read more » over 6 years ago
warren "OK, a bunch of solved problems! figured out the height difference -- needs to be resolved, but I believe due to a bug, we were multiplying each p..." | Read more » over 6 years ago
stoft "Jeff, thanks for pointing this out. I admit I do find the SWB terminology a bit overloaded and the user interface 'unexpected' as I'm not used to i..." | Read more » over 6 years ago
warren "Hi, Dave - i noticed that https://spectralworkbench.org/spectrums/71409 has a linearCalibration operation - I think by mistake, as it's not a CFL. ..." | Read more » over 6 years ago
warren "Also, regarding the unit precision, I've opened an issue at https://github.com/publiclab/spectral-workbench/issues/335 and would love your input on..." | Read more » over 6 years ago
stoft "Understood; though independent checks and tests are still the best method to find hidden anomalies and overlooked issues. When you fix the glitch, ..." | Read more » over 6 years ago