adding noise to video

[naeem561]

how can i add Gaussian noise(mean=0 variance=20) to a video file in yuv format.
can i do it with matlab or do i have to use some other technique.
please help me out.

[Shevach]

I use 'randn' function of Matlab to add Gaussian noise to yuv-file.
For each pixel (regardless luma or chroma) a value is generated by 'randn'.
Then the produced value is scaled by 255 and added to the pixel's magnitude. Finally the new pixel value is clipped to the range [0..255].

[RunningSkittle]

everything you will *ever* need:

http://forum.doom9.org/forumdisplay.php?f=33
http://forum.doom9.org/forumdisplay.php?f=69

if you search you will find several plugins that do Gaussian noise.

here is *one*:
http://kvcd.net/sansgrip/avisynth/
http://kvcd.net/sansgrip/avisynth/Noise_Generators-readme.html

[naeem561]

I use 'randn' function of Matlab to add Gaussian noise to yuv-file.
For each pixel (regardless luma or chroma) a value is generated by 'randn'.
Then the produced value is scaled by 255 and added to the pixel's magnitude. Finally the new pixel value is clipped to the range [0..255].

could u please send me the matlab code for it if u have it,i just can't work it out.
i really appreciate your help.:thanks: