move calibration readme to separate file

README.md

@@ -63,7 +63,7 @@ If you use this work in an academic context, please cite the following publicati
 8. Only a udev rule is needed to run the DVS driver. An installation script is provided in the package `libcaer_catkin`.  
   `$ roscd libcaer_catkin`  (need to source your setup.bash file first, or just do `$ cd libcaer_catkin`)  
   `$ sudo ./install.sh`
-  
+
 9. You can test the installation by running a provided launch file. It starts the driver (DVS or DAVIS) and the renderer (an image viewer).  
     1. First, build the renderer:  
         `$ catkin build dvs_renderer`  
@@ -84,81 +84,20 @@ If you use this work in an academic context, please cite the following publicati
     4. In another terminal, launch the DVS/DAVIS renderer:  
     `$ roslaunch dvs_renderer renderer_mono.launch`  
     You should see a movie with images like this:  
-    
+
         ![slider_depth_renderer](https://cloud.githubusercontent.com/assets/8024432/25312371/9afd4180-2817-11e7-9e33-cdaa8af1e6ed.png)
-    
+
 11. Optional: in the case of a **live stream** from the DAVIS (i.e., not a recorded file) you may adjust the DVS/DAVIS parameters to your needs using the dynamic reconfigure GUI. Run  
    `$ rosrun rqt_reconfigure rqt_reconfigure`  
    and a window will appear. Select the `davis_ros_driver` (on the left panel) and you should get the following GUI that allows you to modify the parameters of the sensor.
-   
+
    ![davis_ros_driver_rqt_reconfigure](https://cloud.githubusercontent.com/assets/8024432/25172274/c1267b8a-24f0-11e7-8130-af551a8a958d.png)
-   
+
    A guide on how to modify the parameters in the bottom half of the GUI (biases) can be found here: https://inilabs.com/support/hardware/biasing/
 
-# DVS Calibration
-The calibration of a DVS is a two-stage procedure.
-First, the focus must be adjusted.
-Then, the intrinsic camera parameters are estimated.
-
-## Focus Adjustment
-Adjust the focus of the DVS. One way of achieving this is using a special pattern, e.g. the [Back Focus Pattern](https://github.com/uzh-rpg/rpg_dvs_ros/blob/master/dvs_calibration/pdf/backfocus.pdf).
-
-## Instrisic Parameters
-To run the intrinsic camera calibration, we use a 5x5 LED board that is blinking at 500Hz.
-The calibration procedure is then started using  
-`$ roslaunch dvs_calibration dvs_intrinsic.launch`  
-You will see an RQT interface with all necessary information.
-Top left is the calibration GUI, which displays the amount of detected patterns.
-**Currently, pattern detection does not seem to work indoors. Try close to a window.**
-Collect at least 30 samples before starting the calibration.
-**This can take up to a few minutes** and freezes your RQT GUI.
-Once done, the calibration parameters are shown and can be saved.
-The camera parameters will be stored in `~/.ros/camera_info`.
-When you plug that DVS again, this calibration file will be loaded and published as `/dvs/camera_info`.
-
-The image viewers below show the following:
-
-1. Accumulated DVS renderings: you should see the blinking LEDs and the gradients in the scene
-2. Detected blinking: black regions mean more detections. Once the pattern is detected, the counter in the calibration GUI should increment. The detected pattern is also visualized for a short moment.
-3. Rectified DVS rendering: once the calibration is done, you can see how well it turned out. Check if straight lines are still straight, especially in the border of the image.
-
-
-# Stereo DVS Calibration
-
-## Setup
-Connect the two DVS from OUT (master) to IN (slave).
-GND must not be connected if both DVS are connected over USB to the same computer, to avoid ground loops.
-Time synchronization is performed automatically in the driver software.
-Since each DVS has a separate driver, the ROS messages might arrive at different times.
-However, the timestamps within the messages are synchronized.
-
-## Calibration
-1. Calibrate each DVS independently
-2. Use `$ roslaunch dvs_calibration dvs_stereo.launch`  
-3. Use the same checkerboard with blinking LEDs and make sure it is visible in both cameras. Collect at least 30 samples.
-4. Start the calibration and check the reprojection error. Then save it (this will extend your intrinsic camera info files with the stereo information).
-
-
-# Calibration Details and Parameters
-The calibration requires a board with a regular grid of blinking LEDs.
-In our case we have a 5x5 grid with a 0.05m distance between the LEDs.
-One of the rows can be turned off (to make a 5x4 grid) to avoid confusion in the stereo case.
-The following parameters can be tuned using ROS parameters:
-* `dots_w`, `dots_h` (default: 5) is the number of rows and columns in the grid of LEDs
-* `dot_distance` (default: 0.05) is the distance in **meters** between the LEDs
-
-If you have your own LED board with different LEDs or blinking frequencies, you might want to tweak these parameters as well:
-* `blinking_time_us` (default: 1000) is the blinking time in **micro**-seconds
-* `blinking_time_tolerance_us` (default: 500) is the tolerance in **micro**-seconds to still count the transition
-* `enough_transitions_threshold` (default: 200) is the minimum number of transitions before searching the LEDs
-* `minimum_transitions_threshold` (default: 10) is the minimum number of transitions required to be considered in the LED search
-* `minimum_led_mass` (default: 50) is the minimum "mass" of an LED blob, i.e., the sum of transitions in this blop
-* `pattern_search_timeout` (default: 2.0) is the timeout in **seconds** when the transition map is reset (it is also reset when the LED grid was found)
-
-
-# DAVIS Calibration
-We recommend to use the frames for intrinsic calibration for the DAVIS.
-More details can be found here for [monocular](http://wiki.ros.org/camera_calibration/Tutorials/MonocularCalibration) and [stereo](http://wiki.ros.org/camera_calibration/Tutorials/StereoCalibration).
+
+# Calibration
+For intrinsic or stereo calibration of the DVS and DAVIS, please have a look at the following [document](dvs_calibration/README.md).
 
 
 # Troubleshooting

dvs_calibration/README.md

@@ -0,0 +1,63 @@
+# DAVIS Calibration
+We recommend to use the frames for intrinsic calibration for the DAVIS.
+More details can be found here for [monocular](http://wiki.ros.org/camera_calibration/Tutorials/MonocularCalibration) and [stereo](http://wiki.ros.org/camera_calibration/Tutorials/StereoCalibration).
+
+# DVS Calibration
+The calibration of a DVS is a two-stage procedure.
+First, the focus must be adjusted.
+Then, the intrinsic camera parameters are estimated.
+
+## Focus Adjustment
+Adjust the focus of the DVS. One way of achieving this is using a special pattern, e.g. the [Back Focus Pattern](https://github.com/uzh-rpg/rpg_dvs_ros/blob/master/dvs_calibration/pdf/backfocus.pdf).
+
+## Intrinsic Parameters
+To run the intrinsic camera calibration, we use a 5x5 LED board that is blinking at 500Hz.
+The calibration procedure is then started using  
+`$ roslaunch dvs_calibration dvs_intrinsic.launch`  
+You will see an RQT interface with all necessary information.
+Top left is the calibration GUI, which displays the amount of detected patterns.
+**Currently, pattern detection does not seem to work indoors. Try close to a window.**
+Collect at least 30 samples before starting the calibration.
+**This can take up to a few minutes** and freezes your RQT GUI.
+Once done, the calibration parameters are shown and can be saved.
+The camera parameters will be stored in `~/.ros/camera_info`.
+When you plug that DVS again, this calibration file will be loaded and published as `/dvs/camera_info`.
+
+The image viewers below show the following:
+
+1. Accumulated DVS renderings: you should see the blinking LEDs and the gradients in the scene
+2. Detected blinking: black regions mean more detections. Once the pattern is detected, the counter in the calibration GUI should increment. The detected pattern is also visualized for a short moment.
+3. Rectified DVS rendering: once the calibration is done, you can see how well it turned out. Check if straight lines are still straight, especially in the border of the image.
+
+
+# Stereo DVS Calibration
+
+## Setup
+Connect the two DVS from OUT (master) to IN (slave).
+GND must not be connected if both DVS are connected over USB to the same computer, to avoid ground loops.
+Time synchronization is performed automatically in the driver software.
+Since each DVS has a separate driver, the ROS messages might arrive at different times.
+However, the timestamps within the messages are synchronized.
+
+## Calibration
+1. Calibrate each DVS independently
+2. Use `$ roslaunch dvs_calibration dvs_stereo.launch`  
+3. Use the same checkerboard with blinking LEDs and make sure it is visible in both cameras. Collect at least 30 samples.
+4. Start the calibration and check the reprojection error. Then save it (this will extend your intrinsic camera info files with the stereo information).
+
+
+# Calibration Details and Parameters
+The calibration requires a board with a regular grid of blinking LEDs.
+In our case we have a 5x5 grid with a 0.05m distance between the LEDs.
+One of the rows can be turned off (to make a 5x4 grid) to avoid confusion in the stereo case.
+The following parameters can be tuned using ROS parameters:
+* `dots_w`, `dots_h` (default: 5) is the number of rows and columns in the grid of LEDs
+* `dot_distance` (default: 0.05) is the distance in **meters** between the LEDs
+
+If you have your own LED board with different LEDs or blinking frequencies, you might want to tweak these parameters as well:
+* `blinking_time_us` (default: 1000) is the blinking time in **micro**-seconds
+* `blinking_time_tolerance_us` (default: 500) is the tolerance in **micro**-seconds to still count the transition
+* `enough_transitions_threshold` (default: 200) is the minimum number of transitions before searching the LEDs
+* `minimum_transitions_threshold` (default: 10) is the minimum number of transitions required to be considered in the LED search
+* `minimum_led_mass` (default: 50) is the minimum "mass" of an LED blob, i.e., the sum of transitions in this blop
+* `pattern_search_timeout` (default: 2.0) is the timeout in **seconds** when the transition map is reset (it is also reset when the LED grid was found)