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2017-12-22 05:07:09 -0600 commented question Camera calibration

I have a dataset of around 250 images, from different angles. I used the default calibrate function from opencv and cali

2017-12-21 04:51:09 -0600 asked a question Camera calibration

Camera calibration Hi, I'm using the default camera calibration from opencv to calibrate a Raspberry pi camera. I ran t

2017-11-15 01:52:38 -0600 commented answer Marker pose calculation with solvepnp

@Tetragramm you're been really helpfully! But one last question, does the order of the points need to be same always? Fo

2017-11-14 05:00:20 -0600 commented question HoughLinesP not able to detect lines

@ziri that's what I'm trying now. Do you know a way to detect if a boundingrect has boundingrects inside?

2017-11-14 02:54:48 -0600 commented question HoughLinesP not able to detect lines

I edited the post

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2017-11-14 02:54:12 -0600 edited question HoughLinesP not able to detect lines

HoughLinesP not able to detect lines Hi, I have been struggling with detecting straight lines with HoughLines() after I

2017-11-13 11:15:28 -0600 asked a question HoughLinesP not able to detect lines

HoughLinesP not able to detect lines Hi, I have been struggling with detecting straight lines with HoughLines() after I

2017-11-13 06:18:28 -0600 commented answer Marker pose calculation with solvepnp

So if I'm correct for the objectPoints I have to create an array of the different points of interests. And for example i

2017-11-13 06:17:38 -0600 commented answer Marker pose calculation with solvepnp

So if I'm correct for the objectPoints I have to create an array of the different points of interests. And for example i

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2017-11-12 17:13:49 -0600 asked a question Marker pose calculation with solvepnp

Marker pose calculation with solvepnp Hi, I'm trying to get my rectangular marker pose via the solvepnp() function. It

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2017-11-12 12:57:14 -0600 commented question Detecting marker

Thank you, I will look into that! I already use them and i know how awesome they are, but some people say I have to thin

2017-11-12 11:52:21 -0600 asked a question Detecting marker

Detecting marker Hi, What is the best way to detect a self-made marker? The marker will be an black rectangle stroke wi

2017-11-12 11:25:09 -0600 marked best answer Kalman filter matrices

Hi,

I'm working with a kalman filter but I can't figure out or can't find documentation about the different matrices. I'm wondering what the values of the next matrices must be:

setIdentity(KF.measurementMatrix);
setIdentity(KF.processNoiseCov, Scalar::all(1e-5));
setIdentity(KF.measurementNoiseCov, Scalar::all(1e-1));
setIdentity(KF.errorCovPost, Scalar::all(1));

Thanks!

2017-11-06 10:14:40 -0600 asked a question Kalman filter matrices

Kalman filter matrices Hi, I'm working with a kalman filter but I can't figure out or can't find documentation about th

2017-10-26 15:40:56 -0600 commented question Aruco marker coordinates on frame

I want to print the 4 points

2017-10-26 08:53:25 -0600 asked a question Aruco marker coordinates on frame

Aruco marker coordinates on frame Hi, I'm searching for an easy way to get the coordinates of the detected aruco marker

2017-10-09 06:53:31 -0600 received badge  Supporter (source)
2017-10-09 06:53:30 -0600 marked best answer OpenCV camera calibration error: OpenCV Error: Unknown error code -49 (Input file is empty) in cvOpenFileStorage

I'm trying to calibrate my PICamera with the camera_calibration.cpp sample. I have taken 6 images from the sample chessboard. cmake and make work, but after running camera_calibration got the following error:

./camera_calibration default.xml
This is a camera calibration sample.
Usage: calibration configurationFile
Near the sample file you'll find the configuration file, which has detailed help of how to edit it.  It may be any OpenCV supported file format XML/YAML.
OpenCV Error: Unknown error code -49 (Input file is empty) in cvOpenFileStorage, file /tmp/binarydeb/ros-kinetic-opencv3-3.2.0/modules/core/src/persistence.cpp, line 4422
terminate called after throwing an instance of 'cv::Exception'
  what():  /tmp/binarydeb/ros-kinetic-opencv3-3.2.0/modules/core/src/persistence.cpp:4422: error: (-49) Input file is empty in function cvOpenFileStorage

Aborted (core dumped)

Google doesn't want to give me an answer this time, hope someone else does. I used this http://docs.opencv.org/2.4/doc/tutorials/calib3d/camera_calibration/camera_calibration.html guide.

I have all the files, images,... in 1 folder. default.xml

<?xml version="1.0"?>
<opencv_storage>
<Settings>
  <!-- Number of inner corners per a item row and column. (square, circle) -->
  <BoardSize_Width> 9</BoardSize_Width>
  <BoardSize_Height>6</BoardSize_Height>

  <!-- The size of a square in some user defined metric system (pixel, millimeter)-->
  <Square_Size>27</Square_Size>

  <!-- The type of input used for camera calibration. One of: CHESSBOARD CIRCLES_GRID ASYMMETRIC_CIRCLES_GRID -->
  <Calibrate_Pattern>"CHESSBOARD"</Calibrate_Pattern>

  <!-- The input to use for calibration.
        To use an input camera -> give the ID of the camera, like "1"
        To use an input video  -> give the path of the input video, like "/tmp/x.avi"
        To use an image list   -> give the path to the XML or YAML file containing the list of the images, like "/tmp/circles_list.xml"
        -->
  <Input>"VID5.xml"</Input>
  <!--  If true (non-zero) we flip the input images around the horizontal axis.-->
  <Input_FlipAroundHorizontalAxis>0</Input_FlipAroundHorizontalAxis>

  <!-- Time delay between frames in case of camera. -->
  <Input_Delay>100</Input_Delay>

  <!-- How many frames to use, for calibration. -->
  <Calibrate_NrOfFrameToUse>26</Calibrate_NrOfFrameToUse>
  <!-- Consider only fy as a free parameter, the ratio fx/fy stays the same as in the input cameraMatrix.
       Use or not setting. 0 - False Non-Zero - True-->
  <Calibrate_FixAspectRatio> 1 </Calibrate_FixAspectRatio>
  <!-- If true (non-zero) tangential distortion coefficients  are set to zeros and stay zero.-->
  <Calibrate_AssumeZeroTangentialDistortion>1</Calibrate_AssumeZeroTangentialDistortion>
  <!-- If true (non-zero) the principal point is not changed during the global optimization.-->
  <Calibrate_FixPrincipalPointAtTheCenter> 1 </Calibrate_FixPrincipalPointAtTheCenter>

  <!-- The name of the output log file. -->
  <Write_outputFileName>"out_camera_data.xml"</Write_outputFileName>
  <!-- If true (non-zero) we write to the output file the feature points.-->
  <Write_DetectedFeaturePoints>1</Write_DetectedFeaturePoints>
  <!-- If true (non-zero) we write to the output file the extrinsic camera parameters.-->
  <Write_extrinsicParameters>1</Write_extrinsicParameters>
  <!-- If true (non-zero) we show after calibration the undistorted images.-->
  <Show_UndistortedImage>1</Show_UndistortedImage>

</Settings>
</opencv_storage>

VID5.xml

<opencv_storage>
<style type="text/css" id="night-mode-pro-style"/>
<link type="text/css" rel="stylesheet" id="night-mode-pro-link"/>
<images>
57.jpg ...
(more)
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2017-10-09 06:53:18 -0600 commented answer OpenCV camera calibration error: OpenCV Error: Unknown error code -49 (Input file is empty) in cvOpenFileStorage

I have no idea where it came from :) But removing both lines, inserting <?xml version="1.0"?> and using the full p

2017-10-09 04:45:02 -0600 asked a question OpenCV camera calibration error: OpenCV Error: Unknown error code -49 (Input file is empty) in cvOpenFileStorage

OpenCV camera calibration error: OpenCV Error: Unknown error code -49 (Input file is empty) in cvOpenFileStorage I'm try