sudo apt-get install imagemagick

I’ve listed a couple of image manipulations that I often use:

1. Batch Image Resize

Suppose you want to batch resize pictures in a specific folder, you could use:

mogrify  -resize 800×600 *.jpg

Note: If  you wanted to get all the details of the operations, use

mogrify -debug all -resize 800×600 *.jpg

2. Change the Image Format

You can also change the format of images quickly using mogrify. The following line of code allows you to convert jpg files into png:

mogrify -format png *.jpg

3. Rotate Images

Mogrify permits you to batch rotate pictures easily. Try the following code to rotate a picture called mypic.jpg by 90° clockwise:

mogrify -rotate 90 mypic.jpg

Final Words…

You should note that mogrify will overwrite all your files. If you want to keep your original files, there are two ways of proceeding.

The first way is to copy the files into another folder before processing them. You can do it on the terminal itself:

cd /home/rikesh/Documents/pics
mkdir new
cp /home/rikesh/Documents/pics/* /home/rikesh/Documents/pics/new
cd new

The above lines of codes allowed me to create a new folder called new and to copy all contents of the pics folder to the new folder. This way, I’ll keep the original pictures.

The second way is to use convert instead of mogrify. Both of them can be used in almost the same way. The main difference between convert and mogrify is that the former creates a new copy of the image.

Do note that sometimes, your camera may give you file extensions like JPG instead of jpg. In this case, you should modify the above codes and use JPG instead of jpg.

Mogrify is very a very powerful tool, and you can have a look at its manual page to get more ideas about how you’ll use it. And don’t forget to share with us :)

Most of the examples in this article will deal about your Facebook account, but the same principle should be applied everywhere.

Why do people want your accounts?

Spammers and scammers are consistently looking for new means to “promote” their stuff. They generally deploy massive phishing schemes to get the maximum number of victims.

However, sometimes, it could be your jealous boyfriend/girlfriend or ex who wants to spy on you. It could be a person who doesn’t like you. Or, just anyone else! Better be on your guards.

Phishing, sniffing and keylogging

You often hear people say that their accounts have been hacked, haven’t you? Should you blame Facebook, Twitter, Gmail, Hotmail or Yahoo for that? Does it mean that these companies should improve their security? Although they sometimes get attacked by hackers, these companies know their business and it’s very hard for someone to intrude their systems.

So, whenever your friend says that his account has been hacked, this is what it means: Either someone has phished him and he fell into the trap, or somebody sniffed his password, or somebody is keylogging him.

What is phishing?

Basically, phishing is taking the victim to a fake web page so that he puts his username and password there. The username and password are stored in a file – which the culprit will then acquire afterwards – and the page gets forward to the real web page. It is, however, possible to differentiate between a spoofed website and a legitimate one.

Do a proper login. Never click strange links from emails. If you want to login to Facebook, always go to the home page via your browser. Use secure login (eg. https://www.twitter.com) where available.

What is Sniffing

Sniffing occurs on wired LANs and wireless LANs (a.k.a wifi). Anyone connected to the network can ‘sniff’ the packets moving in the network.

What is Keylogging

A keylogger is a malicious software that tracks each key you press on your keyboard. Some keyloggers can even take screen shots of your computer at regular intervals. These logs are either stored on the disk itself or mailed to the culprit. Generally, an up-to-date antivirus will detect it.

Don’t expose your real life publicly

Know what privacy settings available. The contents of your profile should only be visible to your “friends” – when I say “friends”, I mean people you know in real life. Don’t add too personal details like your address, phone number, birthday, and so on.

But why not the birthday?

You must be thinking that it isn’t cool to hide your birthday, and that your dear friends must know about that. I agree, but unfortunately, everybody won’t use your birth date to send you birthday wishes. Even if your birthday is available to your friends only, that could be bad. Remember, not all your friends are friends. Somebody could have added you from a fake profile just to get your birthday and then use it to access your account.

Let me explain:

1. Facebook currently has a little security option – if someone not from your location signs in your account, that person must enter your birth date before getting access to your profile.
2. Have you ever lost your email password? Either you genuinely lost the password or your account has been compromised somehow. When this awkward situation occurs, you have to fill a form to get your account back. One of the info you have to add is your birth date. Where’s the problem in that?  Sometimes, somebody with malicious intents may deliberately try to revert your account. He’ll get stuck if he doesn’t know your exact birthday.
3. Let’s get creative. You don’t like a friend called Mr X and you know that Mr X doesn’t know much about computers. You somehow managed to add him on a social network (maybe via a fake profile) and get to know his birthday.  On the birth date of Mr X, you send him a spoofed email with a keylogger attached to it. In the mail, you write that someone just sent Mr X a Happy Birthday greeting, which can be viewed after downloading the attachment. So, Mr X sees the mail, gets happy about someone wishing him, opens the mail, and runs the attachment which installs a keylogger on his machine. Not knowing much about online security, Mr X didn’t update his antivirus and the latter failed to detect the keylogger. So, now you can monitor his activities. Now, just imagine that you could have been Mr X.

Has your account been compromised?

If you see that you are now friends with people you don’t know on Facebook, or your friends tell you they are getting weird emails from you, it is highly probable that someone else has your password. There is a simple solution for that: Just change your passwords regularly.

Use Strong passwords!

Always use strong passwords for your accounts. A strong password is one that has a mix of numbers, small caps letters, capital letters, punctuation and symbols. Do not use your birthday, name of your relatives, your phone number and other easy-to-guess passwords. By the way, the most common password people use is 123456, and you should avoid that!

Always use such passwords since they take more time to crack. Let us see how to make a strong password. Assume you are using a simple password: ‘ilovepasswords’.

You could add some numbers: ‘ilov3password5’. You can still recognise the password as 3 looks like an inverted E and 5 looks like an S. Just don’t replace every S with 5, you’re becoming predicatable.

Now add some capital letters: ‘ILov3Password5’. That’s simple.

Add some symbols: ‘–ILov3pa$$word5__’. Now, the password just got longer, which means it’s more secure.

If you feel that the previous method is a bit complicated try this one:

Start with the password: ‘ilovepasswords’

Now, look at your keyboard. Retype the password, but one key to the left. In other words, ‘i’ translates to ‘o’, ‘l’ to ‘;’, ‘v’ to ‘b’, etc..

The new password gets: ‘o;pbr[sddeptfd’. Instantly, you made an easy to remember password look difficult to guess.

In Brief: Tips for a more secure online life

1. Don’t expose your personal life.
2. Beware of shared computers as they may have a keylogger installed.
3. Use strong passwords.
4. Always check the URL before logging in a website.
5. Keep your computer clean of virus, adware, malware, etc…
6. Use up-to-date software.

This is only some examples of what can happen to you and how you can prevent such things from happening. You should always be cautious.

Did you ever encounter such problems? What happened and what how did you manage to solve it? Do you have more tips to add? Share it with us!