pmeerw's blog http://pmeerw.dyndns.org/blog total garbage comes to mind en Copyright 2007-2009 Peter Meerwald 60 Sun, 01 Nov 2009 20:26 GMT pmeerw@pmeerw.net PyBlosxom http://pyblosxom.sourceforge.net/ 1.4.3 01/10/2008 Watermark detection in images - captured with mobile phone camera! academic/mobilecam-wm http://pmeerw.dyndns.org/blog/academic/mobilecam-wm.html Experimental setup:
  • A watermark is embedded in a 480x272 color image (at approx. 43 dB PSNR) with no preceptual distortion.
  • The image is displayed with 2x scale-up factor on a TFT display.
  • The screen is photographed with two cameras: a Canon IXUS70 (roughly 7.1 MP) and a Nokia 6300i (2 MP) mobile phone.
  • The target images are manually registered (cropped, rotated, scaled) without holding on to accurate affine distortion compensation. No 'trapeze adjustment' has been performed (don't know how to do that with Gimp :-).
  • Presence of the watermark can be easily detected in the registered image while guaranteeing a low probability of false-positive detection (Pfp = 1e-6).

Here are the test images (click on the thumbnails for full-size images):

Canon IXUS70 Nokia 6300i
Captured
3072x2304		 Registered
480x272		 Captured
1600x1200		 Registered
480x272

IMG_3725.JPG
rIMG_3725.png
Image0007.jpg
rImage0007.png

IMG_3727.JPG
rIMG_3727.png
Image0008.jpg
rImage0008.png

IMG_3728.JPG
rIMG_3728.png
Image0009.jpg
rImage0009.png

]]> /academic Sun, 01 Nov 2009 20:26 GMT Where was I? Where did I take that picture? holux_m241 http://pmeerw.dyndns.org/blog/holux_m241.html Got a Holux M-241 GPS logger. Now the software stack is missing, or isn't it?

]]> Mon, 19 Oct 2009 11:46 GMT FPGA experiments? projects/nexys2 http://pmeerw.dyndns.org/blog/projects/nexys2.html Got nexys2 FPGA board from Digilent (under their academic program). Let's see if I get it to work (with Linux)...

]]> /projects Mon, 19 Oct 2009 11:31 GMT Twitter-enhanced blog projects/blog/twitterenh http://pmeerw.dyndns.org/blog/projects/blog/twitterenh.html My blog is now twitter-enhanced and shows my latest five tweets.

Thanks to Devon Meunier for pybltwitter.py!

]]> /projects/blog Sun, 18 Oct 2009 12:08 GMT Must-read watermarking blog academic/wmblog http://pmeerw.dyndns.org/blog/academic/wmblog.html ... The Watermasked Cucumbers and their watermarking blog!

I wonder who is blogging there :) well, not too much

]]> /academic Mon, 12 Oct 2009 14:24 GMT