JMF: controlling webcam color settings from java

[Roland Poellinger]

hello!

right now i am working on a webcam realtime image processor - that is motion
detection, color recognition, blob tracking etc.

i am working with JMF and a logitech usb cam (the one from the LEGO robotics
system). for the image analysis i would need a stable picture from the
webcam as to the white balance and the automatic gain. the problem: the
camera automatically adjusts itself to new light conditions etc., so that it
is not possible to compare two pictures because of the changing colors!

i happened to find a different program (commercial, windows executable),
that is able to control every single feature of the webcam including
automatic on/off, manual whitebalance, manual gain, etc. - i figured this
has to be possible in java, too.

anyone who knows about a similar project or how to use the JMF or even a JNI
(windows) to control the camera from java??

greetings and thanks in advance -
roland

 

[bauscharln]

problem: the camera automatically adjusts itself to new light conditions
etc., so that it is not possible to compare two pictures because of the
changing colors!
...
this has to be possible in java, too.

Hello Roland,
I'm also playing around with my webcam(also logitech), and image
processing. I just switched from C# to JMF.
In C# i had to use vfw. I didn't adjust the settings programmatically
but with the messages WM_CAP_DLG_VIDEODISPLAY or WM_CAP_DLG_VIDEOSOURCE
I could invoke a Settings-Window, set the parameters manually, and
deactivate the auto-adjust function...

However, I hope you find a more elegant way to achive this. If so, I
would be very interested in the solution.

cheers,
martin

 

[Roland Poellinger]

hello martin!

i have been searching for an appropriate way of addressing the video input
settings all day long...
the commands you used sound like VB or something... i found a description of
them in the windows
development knowledge base at
http://msdn.microsoft.com/library/d...s/multimed/htm/_win32_multimedia_messages.asp
do you think it might be possible to invoke these methods like jni calls? or
even through an exec method on Runtime object? see:
http://mindprod.com/jgloss/exec.html and http://mindprod.com/jgloss/jni.html
..

because it would indeed be the easiest if not elegant (since not platform
independent) solution for this problem... considering it like a printing
dialog...

but anyways - thanks for answering my question - there does not seem to be
very much information about this in the web...!!

greetings - roland