02-01-2010
9 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Ok, I'm confused.
Can someone answer these (stupid) questions please for me?
1. What is the difference between unix and linux?
2. Is FreeBSD a unix distribution?
3. If not, then what is Unix? I actually gone to Unix.com because I thought this is it's official website where I could download... (1 Reply)
Discussion started by: RellioN
1 Replies
2. UNIX for Dummies Questions & Answers
OK, I've used various versions of UNIX(Solaris, HPUX, etc..) over the years. Now the organization I work for is leaning towards more Linux based systems(Redhat, Suse, etc..)
I do see differences in in comands and how to accomplish basic adminstration, but nothing mind blowing.
So, what is it... (5 Replies)
Discussion started by: pbonilla
5 Replies
3. UNIX for Dummies Questions & Answers
What is the difference bettween linux and unix?
Sorry but I am really new to this! :confused:
Also are they BOTH free :-D (1 Reply)
Discussion started by: jamesthemagicia
1 Replies
4. UNIX for Dummies Questions & Answers
Hello all
the su with -l option is running normal with linux but when i try to run it on unix AIX 5.2.7 it's not working with -l option
any help (6 Replies)
Discussion started by: islam.said
6 Replies
5. UNIX for Dummies Questions & Answers
I'm having a problem regarding the encoding of my files in Linux and AIX.
I have a file which can be viewed both in Linux and AIX (via NetApp mount). When I checked the encoding, they have difference.
In Linux, the file is encoded as ISO-8859 text. (checked by using "file" command).... (1 Reply)
Discussion started by: Jin_
1 Replies
6. UNIX for Dummies Questions & Answers
Hi I am new to linux
I have dout waht is the difference between UNIX and LINUX
Is there any soft for insatallation for UNIX OS
Thanks (0 Replies)
Discussion started by: sanjaya
0 Replies
7. UNIX for Dummies Questions & Answers
hi experts please tell me the real difference between unix and linux at kernel structure (1 Reply)
Discussion started by: linurag
1 Replies
8. Red Hat
Hi All,
The scripts developed in AIX can be executed in Red Hat Linux too? Because, we are migrating OS from AIX to LINUX.
Will there be any differences in commands?
Thanks in advance!!!
Regards,
U (2 Replies)
Discussion started by: unme
2 Replies
9. UNIX for Dummies Questions & Answers
Moving from AIX 6.1 to RHEL 6.6, I have noticed a few command differences.
One that has been causing issue is a simple echo command when I have to use it this way -> "echo -e"
On the AIX it outputs to "-e" but since RHEL has "-e" as an option for echo and hence it outputs to blank here.
All... (3 Replies)
Discussion started by: aster007
3 Replies
LEARN ABOUT REDHAT
pnmpsnr
pnmpsnr(1) General Commands Manual pnmpsnr(1)
NAME
pnmpsnr - compute the difference between two images (the PSNR)
SYNOPSIS
pnmpsnr [pnmfile1] [pnmfile2]
DESCRIPTION
Reads two PBM, PGM, or PPM files, or PAM equivalents, as input. Prints the peak signal-to-noise ratio (PSNR) difference between the two
images. This metric is typically used in image compression papers to rate the distortion between original and decoded image.
If the inputs are PBM or PGM, pnmpsnr prints the PSNR of the luminance only. Otherwise, it prints the separate PSNRs of the luminance, and
chrominance (Cb and Cr) components of the colors.
The PSNR of a given component is the ratio of the mean square difference of the component for the two images to the maximum mean square
difference that can exist betwee any two images. It is expressed as a decibel value.
The mean square difference of a component for two images is the mean square difference of the component value, comparing each pixel with
the pixel in the same position of the other image. For the purposes of this computation, components are normalized to the scale [0..1].
The maximum mean square difference is identically 1.
So the higher the PSNR, the closer the images are. A luminance PSNR of 20 means the mean square difference of the luminances of the pixels
is 100 times less than the maximum possible difference, i.e. 0.01.
SEE ALSO
pnm(5)
04 March 2001 pnmpsnr(1)