KLCalVid: A tool for calibration device position determination using CCD
cameras
KLCalVid is a tool to superimpose a 3D model of KamLAND and
±5-cm octahedron "target" onto a live video picture. It's like
a computer-aided graticule. This tool is intended to be used with the
inner detector CCD
cameras to measure and monitor calibration source position; it
might also help in quantifying any optical distortions caused by
turbulence. A formal KamLAND Note
describes the theory and operational requirements in detail. I've got
it working under Windows 98 on my home PC (which has a cheap video
grabber) and in my office and at the mine (using a high-quality video
digitizer bought for this project). If you have a Windows machine
with a Video-for-Windows-compatible camera or video capture device
(anything that works with Microsoft NetMeeting should work), then
please consider downloading the executable file below and let me know
if it works on your system.
I've also made a "simulator" which works under X-windows, just to test
how easy it is to align images and model. The simulator superimposes
the model on a saved bitmap if you add "-image (filename)" to the
command line. (Use "xpm" link below to download some saved images
from the real experiment.) You can try out the simulator if you like.
(It's fun!) You can download the source below.
For a quick tour of the simulator, start it using "klcvsim_x -image
M13-3-6.xpm". Press "h" for help. Hit the spacebar to turn the lines
into dots. To align the model with with the image, hit "4" (to get
the 13-3-6 camera view), zoom in a bit (using the 'e' key), and pan
right and up a bit ('i','k'), and then fine-tune the tilt, zoom, etc.
The Windows version also has Save and Load Bitmap commands, and
can be used as a simulator by turning off the video and loading a
saved bitmap.
The KamLAND Note also includes sample images from the simulator, so
you don't have to get the simulator if you don't want to.
The note
"Calibration device position determination using existing CCD cameras"
(PDF, 748 kB)
The software
Screen shots
Screen shot of KLCalVid application running with live video
capture under Windows in the author's
office.
Screen shot of KLCalVid application with model aligned to
image from KamLAND fixed camera F44-28. Model in "dots mode" to
enhance visibility of image. Only the LEDs on the frame opposite the
camera are visible in this image. Image was saved Nov 23, 2001, using the
same digitizer card to be used in the final installation.
Ten frame exposure of image with changing features.
Note green color of moving hand against darker background:
KLCalVid saves the maximum brightness in the green channel, the
minimum brightness in the blue channel, and the average brightness in
the red channel. This is intended to help in identifying changing
features, such as a flashing beacon.
Miscellaneous things
This page maintained by
G. Horton-Smith.
Last update January 22, 2002.
Please contact me if you have any questions.
