Calibrate the HoTDeC Vision system

From HotDec

1 General Procedure
2 Problems & Solutions
- 2.1 Unable to open device
- 2.2 The RGB picture is not correct

General Procedure

If you have not yet installed the Vision Client see HoTDeC Vision Client.

In the working directory 'hotdec/vision_client' there is a program 'calibrate'. This program handles the calibration process. It will give you various prompts and save images to the 'hotdec/vision_client/IMAGES' folder for your evaluation.

Run the following commands:

cd hotdec/vision_client
gthumb IMAGES & ./calibrate

Usual values:

Exposure 410
Sharpness 70
Saturation 255
Gamma 1
Shutter 2
Gain 87
Iris 4

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Problems & Solutions

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Unable to open device

Problem: You get the following message:

(dc1394_capture.c) unable to open video1394 device /dev/video1394/0
dc1394_capture.c: No such file or directory

This means you did not do the /dev fixup in the installation process. See HoTDeC Vision Client.

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The RGB picture is not correct

If the full-color photo does not seem correct (too dark, blue tint, etc.) then you need to manually change the 'client#_cam_params.h' file. To find the correct settings for this file, view the output in coriander and change settings until the picture is correct. Its not as important to have a natural-looking picture as it is to have a contrast between the red, green and blue colors of the hovercraft and the white-yellow color of the floor.

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Install Coriander

To install coriander, add the 'universe' repository to the apt system (vim /etc/apt/sources.list for details) and install via 'apt-get update && apt-get coriander'.

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Use Coriander

Run coriander. Select the camera to adjust under 'Camera Select'. The top selection is camera 0. Click the 'Services' tab. Click the 'Recieve' and 'Display' buttons. Click the 'Features tab'. Adjust the sliders until the picture comes in correctly. Copy these values to the 'client#_cam_params.h' file.

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