Screensavers are used to cover the desktop with some images or graphics while we are away from the system.
Here is how we can enable the screen saver from the command line. The screen saver from the command line will basically turn the screen blank and turn it on again only on detecting a user activity or when the command to turn off the screen saver is sent.
The first step to activate screensaver from the command line is the start the screensaver using the command
After the command has been executed we can activate the screensaver using the command
$ gnome-screensaver-command -a
As soon as the command is executed the screen turns blank and comes back to life on any press of key or mouse movement.
Note that after being activated it will prompt for the user password before displaying the desktop.
We can also simulate a user activity from command line by passing the option “-p” to the command gnome-screensaver-command, which is equivalent to poking the screensaver like a user.
Thus to make the screen blank for 5 minutes we do
$ gnome-screensaver;gnome-screensaver-command -a;sleep 5;gnome-screensaver-command -p
The above set of command will make the screen blank for 5 seconds and then reactivate the screen after 5 seconds.
To prevent from being prompted for password on activation of the screen, we can use the option -d instead of -p, which is to deactivate the screensaver.
We can create a script with the above commands, as required, and add it to the panel as a quick launcher, to give us the facility of quickly blanking the screen whenever required.
Using gimp we can create animated gif image with a blending effect, that is one image blends into another as shown below.
Here is how we can create the above animation in gimp.
First we need the images we need to use for the blend effect, in the above animation we have used the following three images created using gimp itself.
They can be created using the logo creation tool available under file->create->logos and the above effect is glossy.
Once the images are ready, open gimp.
choose a template size bigger than the biggest of the images to be used in animation and click on ok.
Drag and drop the images into gimp in the order in which the images have to appear in the animation.
For the above animation we will drop “linux.jpg” first, then “is.jpg” and then “”freedom.jpg”.
Now click on filter->animation->blend.
The following menu will appear.
The number of intermediate frames decide how slow the transition from one image to another should happen. In the above animation we have chosen the number to be 20 to make the transition happen slowly.
The blur option is to choose how much should the image blur before appearing and disappearing, the above animation has 0 blur. Click on “ok” and wait for gimp to do the magic. Once done we should see a new window as follows.
To preview the animation click on filter->animation->playback
Click on the play button to see the animation. If the animation is satidfactory close the preview and save the animation by clicking on
Enter the name and add the extension .gif example blend.gif
A menu as below will be shown, click on save as animation and click on export
In the next window we can choose the delay between individual frames, but in this case we can leave it as default and click on save and the animation should be ready.