Mapping the Repeat function to F4 key in OOCalc

People migrating to OOCalc after years of experince in MS Excel will notice that pressing the F4 key doesn’t give the desired it won’t repeat the previous action. Even though Ctrl+Shift+Y will do the job, they badly want the functionality to be remapped to the F4 key. Here’s how you do it.

Go to Tools->Customize and select Keyboard Shortcuts. Select the entry corresponding to the F4 key and make the necessary changes to the Category and Function entries as shown in the Figure. Now click on the Modify button and finally click OK. That’s it.

In older versions of OOCalc, (see fig above) the Keys field will be blank when you select the Edit category and the Repeat fucntion. But as soon as you click the Modify button, the Keys field will be filled with the entry F4. The rest is the same.

August 31, 2008. Tags: , , , , . howto, OOCalc. Leave a comment.

Installing OCRopus on Debian/Ubuntu

Make sure that you have the following packages installed.

#apt-get install subversion build-essential ftjam jam libpng12-dev libjpeg62-dev aspell libjpeg62 libtiff4-dev

All these packages are available in the standard repositories, and can be installed with apt-get

Download tesseract by using the following command

$svn co tesseract-ocr

Next install tesseract by issuing the following commands

$cd tesseract-ocr


$sudo make install

Next download and extract the OCRopus package and issue the following commands from the extracted folder



$jam install

Testing OCRopus

If you have been able to get along this far, you will find a directory named ocrocmd with a file with the same name inside the directory that you are currently in. cd into ocrocmd and issue the command

$./ocrocmd test.png > out.html

August 26, 2008. Tags: . howto. 6 comments.

Bulk Resizing images using bash

Say, you have hundreds of multimegapixel images in your big_pics directory, and you want to create thumbnails of all of them and store it in the small_pics dir. Just a single command.

metapixel-prepare -r big_pics small_pics –width=48 –height=48

Make sure that the metapixel package is installed for this command to run. You can install it using the command:

apt-get install metapixel

Metapixel is actually a tool for generating photomosaics. Details can be found here.

December 11, 2007. Tags: , , , , , . howto. Leave a comment.

Creating Screencasts in Debian

Istanbul and Xvidcap are the best options for creating screencasts in Debian. They’re free and are available in Debian’s free repositories. Istanbul gives an ogg file as the output, whereas xvidcap comes up with an mpeg file. An interesting cast of Istanbul screencasting itself is available here.

Another option is Wink. You can install wink in debian using apt-get install (sadly, your non-free repository section has to be enabled for this). This guide should help you to create the first cast. Even though creating a screencast using wink is a smooth sail, you should try to avoid it for two reasons:

  1. Wink is non-free
  2. The output generated is an swf file, which forces your browser to install non-free plugins.

A more challenging way of creating screencasts is described here. The instructions are quite easy to follow, but some of you might get an error message while trying to convert the .miff files to .m2v.

mpeg2encode: command not found

If you get the above error message,

  1. Download this package from
  2. Untar it, cd into the directory and make.
  3. You will find two directories mpeg2dec and mpeg2enc inside the src directory. If the make process is successful, an executable will be created in each of them, namely mpeg2decode and mpeg2encode resp. Copy these executables to /usr/local/bin and repeat the convert process. You should be able to get through this time.

recordMyDesktop, is another tool for the same purpose. An ogg file, containing the screencast will be created in your home folder once the recording is stopped.

December 7, 2007. Tags: , , . howto. 3 comments.