Thursday, December 20, 2012

Vectorizing scans

I am always unhappy about the way my scanned handwritten documents look. Pencil looks especially bad. I have earlier used the fantastic inkscape to trace bitmaps and create vectorized versions of my scans, with success. But the process is somewhat cumbersome, and I tend to forget how to do it between the times I need it.

The result is worth it, though. Black is real black, and since it produces vector graphics the edges are not pixelated, even if you zoom in.

Original scan, grey and pixelated.

After the vectorizing, black and white, and no visible pixelation (you may distinguish pixels here, since I converted the image from pdf to png).

Here comes a way to do it in one command from a terminal.

Wednesday, August 8, 2012

Mounting an exFAT disk in Ubuntu

I recently had trouble mounting an external drive in Ubuntu 11.04.

I take system disc images with dd, from Ubuntu booted with a live CD. One of the steps of the process is to mount the drive where the backup file is to be stored. To do that I need to know the format of the drive.

My problem was that fdisk -l told me that the destination drive was HPFS/NTFS, which was wrong. Connecting the drive to a Windows machine made it clear that it was formatted as exFAT.

Ubuntu does not support the exFAT format in its current distribution (at least not in 11.04), which explains why fdisk gave the wrong information.

If you have trouble connecting an external drive to your Ubuntu install, and fdisk tells you it is NTFS, read on...

Sunday, June 3, 2012

Making system backup smaller

While taking a snapshot of my system disk, I discovered that the image file produced by dd had grown way too large. This post explains what happened and how to solve it.

Sunday, February 19, 2012

Data backup with rsync

After years of backing up personal data on an external disk and keeping the disk in a cupboard, I finally got to implement something a bit more safe.

Off site copy

Having your backup disk at home protects you against data loss in case of disk failure. Should your house burn down, your backup disk would not help much.
If burglars pay you a visit and take your computer, they may just as well take all your electronic equipment as well, including your backup copy.

Friday, November 18, 2011

Disk backup with dd

This post describes how to create an image of a whole disk with dd. I use this to backup my Mac OS X system disk before a major change, for example upgrading from Snow Leopard to Lion. Since I see such operations as risky (not running on Apple hardware), I want to be able to go back to a working state easily.

This process is not limited to Mac OS X, you can follow this guide to create a disk image of whatever disk you want: your windows OS disk, your data, anything.

Here are the steps I am going to go through in this post:
  • start up in linux,
  • find the device name of the disk to backup,
  • find the mounted name of the disk where to save the backup,
  • run the dd command with the appropriate attributes,
  • test that the backup worked.

Tuesday, November 8, 2011

Installing Mac OS X

Installing OS X on a non-apple hardware is easier than it sounds, as long as the hardware is compatible.

Method at tonymacx86

Tonymacx86 provides a standard method for installing Mac OS X on a Sandy Bridge system. This method worked fine for basic funtionality, and only a few more tweaks were needed for sound and network to work.
What you need besides the computer is:
  •  a blank CD, for iBoot and Multibeast
  •  an OS disk purchased from Apple

The method makes it very important not to restart after updating to 10.6.8. That is precisely where my computer crashed, so I had no choice but to restart anyway. That did not seem to cause any problem, though.

From the Multibeast installer, you are presented with two options: EasyBeast and UserDSDT.

Sunday, October 30, 2011

My hackintosh build

I finally decided that Apple was missing to my culture and that it needed to be fixed.

What is a hackintosh?

In short, a hackintosh is a regular PC on which you install Mac OS X. The challenge is that not all hardware is supported, so there is some research to do ahead. You do not want to pay for a fancy graphics card that doesn't work with the OS.


The "it just works" concept did not appeal to me very much. The main idea was to learn, and there is no better way for that than doing it yourself. (To be honest, the price of Apple's hardware helped me make that decision as well.)

Add that I enjoy doing the research and learning about all the new hardware finesses since the last time I built a computer (2005), plus that I appreciate to tackle a challenge.

My old computer was getting crippled and too loud to my taste. These are just further excuses for having fun building a new computer.

As for many decisions people make, I think that my guts just decided to do it, then found or invented seemingly rational reasons.