calibration

R: make pls calibration models from n number of subset and use them to predict different test sets

由 流过昼夜 提交于 2019-12-11 12:44:51
问题 I am trying to apply a function I wrote that uses the 'pls' package to make a model and then use it to predict several test set(in this case 9), returning the R2,RMSEP and prediction bias of each test set for n number of subset selected from the data frame. the function is cpo<-function(data,newdata1,newdata2,newdata3,newdata4,newdata5,newdata6,newdata7,newdata8,newdata9){ data.pls<-plsr(protein~.,8,data=data,validation="LOO")#making a pls model newdata1.pred<-predict(data.pls,8,newdata

Inbuilt sensor calibration functionality in Android

由 亡梦爱人 提交于 2019-12-11 06:32:09
问题 I am working on an application which utilizes accelerometer and magnetometer data and their fused data to function. Now there's an inherent need when it comes to magnetometer to re-calibrate it regularly. The sensor gets uncalibrated due to a phenomena called hard iron effect. My application requires very accurate sensor data (which the hardware is capable of delivering but noise and uncalibrated values create a roadblock). I also know that there are inbuilt calibration functions running in

How to use opencv.omnidir module for dewarping fisheye images

由 空扰寡人 提交于 2019-12-11 02:48:11
问题 I am trying to use omnidirectional module for dewarping fisheye images in Python . I am trying to adapt this C++ tutorial in Python but running into issues. Here is my code: import numpy as np import cv2 import glob nx = 9 ny = 6 # termination criteria criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001) chessboard_model = np.zeros((1, nx*ny, 3), np.float32) chessboard_model[0, :, :2] = np.mgrid[0:nx, 0:ny].T.reshape(-1, 2) # prepare object points, like (0,0,0), (1,0,0),

Calculate Intrinsics for a Thermal Camera?

由 ∥☆過路亽．° 提交于 2019-12-10 13:27:02
问题 I"m using a Thermal camera for a project and I'm a little stumped so as to how to think about calculating intrinsics for it. The usual camera's would determine different points on a chessboard or something similar, but the thermal camera won't really be able to differentiate between those points. Does anyone have any insight on what the intrinsics for thermal cameras would really look like? Cheers! EDIT - In addition to the great suggestions I currently have, I'm also considering using

Accelerometer & Calibration - iPhone SDK

由 谁都会走 提交于 2019-12-09 19:00:42
问题 I need to use the functionality of an accelerometer in my iphone game. I just have to move an image by tilting the device. However most videos on youtube just show the tilt feature that is somehow inverted and forget to include the calibration. I want the user to calibrate their device to whatever position they're in. Does anyone know how I should get started on this? Your help is greatly appreciated, Kevin 回答1: I made an app like this once. I'll post it here, but it's for iOS 4... http:/

How can I display a 5mm grid at the proper scale in a web browser?

由 China☆狼群 提交于 2019-12-07 03:21:05
问题 I'm creating a web application for displaying ECGs, which are conventionally drawn at fixed scales (10 mm/mV and 25 mm/s) on a 5mm square grid. It's important to use the correct size, because readers compare what they see on-screen with other ECGs that may exist only on paper. The most recommended solution is to use CSS to style a div such that it has absolute dimensions of (say) 1" by 1", and to use JavaScript to obtain its height and width (see, for example, How to detect the screen DPI

Use calibration matrix to know CCD sensor size

由 生来就可爱ヽ(ⅴ＜●) 提交于 2019-12-06 04:26:47
问题 How can we know the camera sensor size from the calibration matrix? I already have the calibration matrix. But the focal length is in pixels form. 回答1: The "focal length" in the calibration matrix is not actually expressed in pixels. It is in fact a ratio that relates the sensor size in the real world to the size of a pixel in the image. It relates the focal length of the lens to distances in the image using a scaling factor in each dimension. More details in this article. 回答2: As Zaphod says

Use calibration matrix to know CCD sensor size

由 為{幸葍}努か 提交于 2019-12-04 09:56:03
How can we know the camera sensor size from the calibration matrix? I already have the calibration matrix. But the focal length is in pixels form. The "focal length" in the calibration matrix is not actually expressed in pixels. It is in fact a ratio that relates the sensor size in the real world to the size of a pixel in the image. It relates the focal length of the lens to distances in the image using a scaling factor in each dimension. More details in this article . As Zaphod says, you can get a decent approximation combining the calibration matrix with a known focal length for the lens in

Color consistency between Photoshop, iPhone Simulator, and iPhone

由 陌路散爱 提交于 2019-12-03 21:38:52
I've been working a lot with Photoshop .psd files recently and have been bouncing back and forth a lot to ensure colors look just right on the iPhone. Can anyone offer some tips on calibrating macbook/apple cinema displays in regards to keeping color consistency between Photoshop, the iPhone simulator, and physical iPhones? Have a look on LiveView created by Nicholas Zambetti . You need to install it on your iPad/iPhone/iPod Touch and on your Mac. when synced (Mac and device) you can have a preview of the selected area of your screen (Mac), on your device. Hope this will help you out! Cheers,

Fisheye/Wide-Angle lens Calibration in OpenCV

由 ▼魔方 西西 提交于 2019-12-03 12:18:27
问题 I know the default OpenCV Calibration systems model a Pinhole camera, but I'm working with a system using extremely wide FOV lens (187-degrees). If there any existing way to do this in OpenCV, or to work with just wide lenses? Or will I have to rewrite all the calibration/undistort for my system? 回答1: Seems there's no good OpenCV way to do this. I wound up using OCamLib to do the actual calibration, then writing my own "undistortPoints" function (using Scaramuzza's algorithms) to undistort 2D
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