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Tuesday, November 24, 2009

Changing Screen Resolution in Ubuntu under VirtualBox

Tuesday, November 24, 2009 Posted by Ismail Habib , , , 29 comments
This problem has caused me a relatively severe headache today. I'm doing a project which require me to use a Linux OS. Since I don't have Linux in my office PC, I decided to install one (Ubuntu 9.10) in a VirtualBox instead of creating a double booting configuration. The installation procedure was easy and painless, but then the problem is coming. The installed Ubuntu does not have any option to increase the screen resolution other than 800x600 and 640x480.

I tried to install the suitable driver with no result except destroying my X Window which forces me to reinstall the Ubuntu again (thank God I use virtual machine...). Then I started looking around for a solution and several forums and websites point me to this:

  • Choose Devices -> Install Guest Additions... on the VirtualBox menu
  • It will mount a CD which will appear on the Desktop
  • Go to your terminal (Applications -> Accessories -> Terminal)
  • Go to the CD directory by typing "cd /media/cdrom0" (without the quotes)
  • Type "sudo sh ./VBoxLinuxAdditions-x86.run", again, without the quotes. At the first try I couldn't find this file instead just a directory "OS2". If you experience the same thing, this is probably because you set your VirtualBox OS type as "Ubuntu" instead of "Linux 2.6". In this case, shut down your VirtualBox, change the OS type and redo the whole stuffs from the beginning
  • Restart your VirtualBox


Now, this has successfully gave me another resolution, which is 1024x768. Not bad, but I'm rather greedy and I want something more! (Hey, my PC could do better!). Continue with this:
  • Go to the terminal again
  • Edit the xorg.conf by typing "sudo gedit /etc/X11/xorg.conf" (yes, no quotes)
  • If you can find some already existing screen resolution, then you can add more, otherwise you can include something like this:
Section "Screen"
        Identifier "Screen0"
        Device     "Videocard0"
        DefaultDepth     24
        Subsection "Display"
                Viewport   0 0
                Depth     24
                Modes     "1280x1024" "1024×768"
        EndSubSection
EndSection

  • Be really careful when you're doing this. It is always nice to make a backup beforehand
  • Restart your VirtualBox and enjoy the new screen resolution


Reference:
1. http://www.mikesouthby.co.uk/2009/11/virtualboxubuntu-9-10-changing-screen-resolution/
2. http://www.mjmwired.net/linux/2009/09/15/default-xorg-resolution/

Saturday, November 14, 2009

Improving a Scanned Hand-Drawing

Saturday, November 14, 2009 Posted by Ismail Habib , 34 comments
I did a lot of digital drawing and painting as a hobby. One of the most common problem I faced is the lack of quality of the scanned lines from the scanned drawing. Thus, an improvement on the scanned drawing is required before doing anything else. Before we start, I should warn you that this is the way that I found works, doesn't mean that there is not other way to do it. I'm using Photoshop and Corel Draw to do this, but I suppose any other application with similar features should work fine.

I prefer to trace a scanned hand-drawing before doing anything else. Tracing is nice because with tracing I can have an output in form of vector. Thus, further improvement could be made easily. However, tracing a scanned hand-drawing often caused many detail loss. Increasing trace resolution wouldn't help since the output will not posses simple, clear, and solid lines.

To overcome this situation, I propose to do a preprocessing for the scanned hand-drawing. I'm using a self hand-drawing with a manga-ish style. Forgive the quality, I'm only an amateur :)



Once you scan your hand-drawing, we need to adjust the color intensity. I'm using "Level" feature of Photoshop and adjust accordingly.



The next step is to apply a filter called "Photocopy" from Photoshop. I choose this because it will make the lines bolder and flatten (is this even the correct word?) the color.



The resulting image is good enough for tracing. I import the image and do the tracing with Corel Draw.



The result is clean and artistic. You can always make further adjustment easily since it is in form of vector.