unicap-imaging.org blog - Guides

Basic Image Manipulation with UCIL Part 2

nospam@example.com (Arne Caspari) — Fri, 23 May 2008 19:01:12 +0200

In the first post in this series, I created an example that draws a
crosshair on the video image and a frame counter.

In this post, I will extend the example to write the video stream to
an OGG/THEORA video file.

Continue reading "Basic Image Manipulation with UCIL Part 2"

Updating UCView and Unicap on the ASUS EeePC

nospam@example.com (Arne Caspari) — Wed, 21 May 2008 21:30:08 +0200

I already wrote earlier that the ASUS EeePC comes with unicap and UCView pre-installed. Unfortunately it comes with rather old versions of the software and updates are not yet available via the software update of the EeePC. Also there are no development packages available from the Xandros repositories, so I decided to add EeePC packages for unicap and ucview to the unicap-imaging.org repositories.

Here are the steps necessary to use the unicap-imaging.org repositories on your EeePC and to update to the latest unicap and ucview versions. To follow these instructions, you need to open a terminal window and enter the commands there. Press {Ctrl}+{Alt}+t to open a terminal window.

At first, download the unicap-imaging.org public key from here and import it to the key ring used for package signing:



wget http://www.unicap-imaging.org/downloads/public.key

sudo apt-key add public.key

rm public.key

Next, you need to add the unicap repository to the /etc/apt/sources.list file. To do this, open the file with a text editor:

sudo kate /etc/apt/sources.list

Add the following line to the file:

deb http://unicap-imaging.org/packages/ eeepc main

Then you may save the file and close the editor. Back on the command line, you can update the package info on the eeepc:

sudo apt-get update

Finally, update to the latest versions of unicap and ucview:

sudo apt-get install libunicap-2 libunicapgtk-2 libucil-2 ucview ucview-asus-icons

Now you can enjoy features like uncompressed AVIs and time-lapse recording

Basic Image Manipulation with UCIL Part 1

nospam@example.com (Arne Caspari) — Thu, 08 May 2008 15:03:48 +0200

One part of the unicap toolkit is the UCIL library which contains basic image manipulation functions. Currently it provides drawing functions to draw overlay grahics and text onto the video images, convert between color formats of an image buffer and to write the video stream to a file.

The use of UCIL is quite simple but there might be some caveats. I will try to give a short introduction on UCIL in this series of blog posts.

For this post I modified the callback example which uses GTK+ to display the video image. You can download the whole example here. This example will draw a crosshair and a frame number counter on the video images. In the following posts, I will extend the example to also put a PNG icon on the video image and to store the video to a file.

Continue reading "Basic Image Manipulation with UCIL Part 1"

Installing USB Cameras

nospam@example.com (Arne Caspari) — Wed, 30 Apr 2008 14:47:00 +0200

The Imaging Source AU/BU cameras are a popular series of USB Video Class compliant cameras for industrial and ( more and more ) astronomy vision. If you are wondering about my preference for The Imaging Source cameras, the reason is simply that I am the lead developer of the camera firmware of these cameras.

Before you can use all the features of the USB cameras on Linux, you have to master some hurdles but the installation should be quite easy with the following instructions:

1. Step: Firmware Update

The first hurdle is caused by an issue with the firmware version loaded in most of the USB cameras currently present 'in the field'. This issue prevents the driver from discovering the Shutter control of the camera so that the camera will only work in automatic exposure mode. There is a newer version of the firmware which fixes this issue. You may find the new version and an installer for Linux here.

2.Step: Driver Update

The cameras conform to the USB Video Class ( UVC ) specification which is very well supported by Laurent Pincharts excellent uvcvideo driver.

Most distributions already come with binary packages for the uvcvideo driver for easy installation. But since there have been some fixes to the uvcvideo driver just recently, I recommend to install a never driver from source. The following instructions are made for Ubuntu Linux but the steps are very similar for other distributions. If you do the installation on a different Linux distribution, please post the steps in the comment section if they are different to the ones explained here.

We start with installing a build environment for the driver. On Ubuntu, this can be done with the following command:

sudo apt-get install build-essential linux-headers-generic subversion

Then create some directory where you build the source and get the driver from the linux-uvc website:



mkdir build

cd build

svn checkout svn://svn.berlios.de/linux-uvc/linux-uvc/trunk

The next step is specific to Ubuntu: Since Ubuntu comes with its own (old) uvcvideo driver, you need to make sure that the installation of the driver overwrites the Ubuntu driver. To achieve this, edit the file trunk/Makefile and change the line:
INSTALL_MOD_DIR := usb/media
to:
INSTALL_MOD_DIR := kernel/ubuntu/media/usbvideo

Now you can build and install the driver:



cd trunk

make

sudo make install

Please note that you need to perform the sudo make install step again after each kernel update since the Ubuntu updates will overwrite the freshly installed driver.

Now unload the old driver and load the new one:



sudo rmmod uvcvideo

sudo modprobe uvcvideo

Step 3: Configuring the driver

With the very recent revisions of the driver, root privileges are required to configure the driver to use proprietary extensions to the UVC protocol. The Imaging Source cameras use protocol extensions for a better control of the auto exposure and for functionality like Trigger and Strobe which is not covered by the UVC specification.

The preferred way of the uvcvideo driver to configure the driver is to use a tool called uvcdynctrl which is provided by Logitech.

uvcdynctrl reads a .xml file with a description of the protocol extensions and configures the driver. Since uvcdynctrl is not quite easy to compile and install, I wrote a small python script which you can use alternatively to just set up the driver. You can find the script HERE. You might still want to look at uvcdynctrl since it also contains instructions for a set up with udev, so that the driver is configured automatically when a camera gets connected. I plan to add udev support to uvcctl later.

To configure the driver with the uvcctls script under an Ubuntu system, just download the script and the xml file and enter the following command before you start your application:

sudo uvcctls tisUVC.xml

Finally: Run your application

If you run a unicap application now, all extended features of the The Imaging Source cameras should work. If you use the camera with UCView now, you should see ( depending on your model ), the following features:

A Shutter property allowing you to set an absolute time in 'seconds'

Separate controls for Auto Gain and Auto Shutter

The colour camera should provide three video formats: YUV 4:2:2, Greyscale and RGB Bayer ( the monochrome camera should only provide Greyscale ).

If you have a BU camera, you should now have Trigger functionality