Google Tasks: what it can and cannot do

As you can see on this page, Tasks are accessible from Gmail, from Calendar and from Mobile, through a web browser.

For what I use it for...

Let's begin with the useful parts:

• it is possible to turn an e-mail into a task
• it is possible to drag and drop due tasks in the calendar
• it is possible to make separate lists for separate fields of tasks

Now, there...

• it is not possible to set due date for e-mail tasks with one click.
• for me the best would be if whatever e-mail I turn into a task would turn due for today, because than I can drag and drop it in the calendar.
• it is not possible to archive task items, it is only possible to delete them.
• for this reason my tasks list is hundreds of items long.
• it is not possible to multiple select tasks to move them around in your list or add due date to them
• it is not possible to view different task lists simultaneously in calendar
• therefor I do not use different lists

If you happen to know a solution to the functions I miss, please leave a comment to this post and tell me about it!

DJVU extract images

A useful link:
http://askubuntu.com/questions/46233/converting-djvu-to-pdf

Another useful link: http://unix.stackexchange.com/questions/20592/extract-several-pages-from-a-djvu-file
http://kheyali.blogspot.hu/2011/08/in-order-to-convert-djvu-file-into.html

And another: http://en.wikisource.org/wiki/Help:DjVu_files#DjVu_to_Images


Extract images from DJVU:
DDJVU
The easiest way to do this is probably by extracting to multipage tiff
Than split tiff file with tiffsplit: http://manpages.ubuntu.com/manpages/hardy/man1/tiffsplit.1.html
Than convert to anything useful.
Except that did not work for the file I had...

Okay, so the second way is the script way. Copy the script, paste it to an empty text file. Give it the extension .sh and give it permission to execute as program. Put it in a directory with all the djvu-s you want to extract and run in terminal.

#!/bin/bash
#Ubuntu 10.04 Lucid Lynx

#Put this script file in a directory with all the djvu-s you want to extract and run it in terminal.
#All the DJVU-s in this folder will be extracted to PNM-s.

### Select files to process
#defining the filelist
filelist=(`find -iname '*.djvu' | sort`)
#counting the files in the filelist
element_count=${#filelist[*]}
echo "alltogether $element_count djvu will be processed"

#process only 1 file at a time:
counter=1
echo "processing file:"
for i in "${filelist[@]}"
do
echo -ne "$element_count/$counter"\\r

#Get the number of pages from input file
pagecount=`djvused -e n $i`
#Set a filelist for the pages
 for (( filelist=1; filelist<=$pagecount; filelist+=1 ))
 do
 #Extract with DDJVU
 ddjvu -format=pnm -page=$filelist $i file_$counter.page_$filelist.pnm
 #Or use DjvuPs to extract PS from DJVU the same way:
 #djvups -page=$filelist $i file_$counter.page_$filelist.ps
 done
let "counter = $counter + 1"
done

echo DONE.

Modify PDF pages as images, than reintegrate

what just has happened?!

I successfully reintegrated a modified PDF in the original file!

wow! that is definitely a level up in image-pdf editing for me.

pdftk input.pdf cat 2 output page2.pdf

pdfinfo page2.pdf 
Page size:      595 x 842 pts (A4)

pdfimages page2.pdf img

identify -verbose img-000.pbm
Geometry: 2496x3440+0+0
  Resolution: 72x72
  Page geometry: 2496x3440+0+0

  Modified the image through Gimp. Open, Edit, Save -> Export -> click Ok whenever needed.

convert img-000.pbm -resample 300x300 -resize 2496x3440 img2.ps

identify -verbose img2.ps
  Geometry: 599x826+0+0
  Resolution: 72x72
  Page geometry: 599x826+0+0

ps2pdf12 -sPAPERSIZE=a4 -dFIXEDRESOLUTION img2.ps page2_v2.pdf

pdfinfo page2test4pdf.pdf 
  Page size:      595 x 842 pts (A4)

pdftk A=input.pdf B=page2_V2.pdf cat A1 B A3-end output output.pdf

Crate a link file pointing to web URL

1. Create an empty text file.

2. Copy the following content in it:

[Desktop Entry]
Encoding=UTF-8
Name=Link to Ask Ubuntu
Type=Link
URL=http://www.askubuntu.com/
Icon=text-html

Edit Name and URL to desired name and url.

3. Save file

4. Close file

5. Rename file to have the extension ".desktop"

Done.

Creating searchable PDFs on Ubuntu 2nd try

Need be:

• image layer over text layer
• good character encoding for Hungarian ű and ő chars
• good placement of words and lines
• fair enough good recognition
• handling more column layout

1st try was Tesseract output hocr embedded with hocr2pdf in a pnm file.

• image layer over text layer - YES
• good character encoding for Hungarian ű and ő chars - NO
• good placement of words and lines - NO
• fair enough good recognition - YES
• handling more column layout - NO

the strangest is, that hOCR editor does not handle well the tesseract output hocr. actually it does not handle it at all, showing html tags and everything where the editable text shoud be...

2nd try is: OCRopus 

I had no success installing and using orcopus.

• "recognize" does not handle languages, and/or I could not find a Hungarian data file for it.
  it works like: ocroscript recognize input.pnm > output.html
• rec-tess-complete should recognize through tesseract, and import language files with the --tesslanguage=hun option, but instead I got this error:
  Unable to load unicharset file /usr/share/tesseract-ocr/tessdata/hun.unicharset
• so I unpacked the hun.traineddata like this:
  combine_tessdata -u hun.traineddata hun.
• and put the files to /usr/share/tesseract-ocr/tessdata/
• however I got this error:
  Error: Illegal malloc request size!
  Fatal error: No error trap defined!
  Signal_termination_handler called with signal 2001
• than I tried with --tesslanguage=eng and it gave me:
  ocroscript: /usr/share/ocropus/scripts//rec-tess-complete.lua:52: attempt to call global 'hardcoded_version_string' (a nil value)
• so I searched and found a patch, and installed it like this:
  patch /usr/share/ocropus/scripts/rec-tess-complete.lua rec-tess-complete3_r1308.patch
• and now it gives me (with "eng")
  ocroscript: /usr/share/ocropus/scripts//rec-tess-complete.lua:61: Leptonica is disabled, please compile with it or don't use it!

I already have the newest tesseract on board, but I failed to manage a newest ocropus installation. it had too many unknown aspects with python and all...

results with ocropus 0.3.1-2 recognize and merged with hocr2pdf:

• image layer over text layer - YES
• good character encoding for Hungarian ű and ő chars - NO
• good placement of words and lines - NO (makes large characters, I cannot even tell which line it should be)
• fair enough good recognition - NO (because of english training data)
• handling more column layout - DON'T KNOW (text was too big, it was impossible to tell)

maybe the big text was because of the dpi of the image... I should check on this to at least be able to qualify the layout option... nope, it did not help... at all.

...to be continued with:

3rd try is: Cuneiform

4th try: Adobe Acrobat XI on Windows

Creating searchable PDFs on Ubuntu 1st try

Process is the following:

1. have a good resolution image in leptonica allowed format to use with tesseract: JPEG, PNG, TIFF, BMP, PNM ,GIF and WEBP.
2. produce hocr output like
   tesseract image.pbm textfile -l hun hocr
3. merge image and hocr to searchable pdf in hocr2pdf: image layer on top of text layer like
   hocr2pdf -i input.pbm -o output.pdf < textfile.html

First impressions:

• character encoding after hocr2pdf is off
  setting character encoding in html file header to ISO-8859-2 or Windows-1250 does not help.
  "ő" turns "Q" and "ű" turns "q" :-(
• 2 columns was not recognized automatically in tesseract
  psm option does not solve this
  this is probably impossible in the current version.
  have to try out another way to produce hocr with an ocr software that handles layout.
• font sizes are chaotic
  I think this probably depends on the bbox size and therefor on the ocr software.
• output file size is 159kb from a 818kb pbm, which is way too big.
  this cannot be helped if the pdf is not generated with my own methods...
  

Anyhow, this looks like a disaster :-( character encoding has to work.

Istalling Tesseract

Thanks to THIS post I was able to install tesseract 3 on 10.04 Ubuntu. This is how:

Install Tesseract
Get the required packages available in the repositories:

sudo apt-get install libpng12-dev
sudo apt-get install libjpeg62-dev
sudo apt-get install libtiff4-dev
("sudo apt-get install zlibg-dev" is suggested in the Tesseract readme but isn't available. I found I didn't need this.)

I picked this up from a comment made, you need to be able to compile and make the software. Ubuntu needs some packages to help do this. For many of you these may already be present and installed but it doesn't hurt..

sudo apt-get install gcc
sudo apt-get install g++
sudo apt-get install automake


Download this program which can't be gained with apt-get:
http://www.leptonica.org/download.html version 1.70
unpack, navigate to the folder in terminal, and run:

./configure
make
sudo make install
sudo ldconfig


Now we can actually get and install Tesseract!

download tesseract: https://code.google.com/p/tesseract-ocr/downloads/list version 3.02.02
unpack, navigate to the folder in terminal, and run:

./configure
make
sudo make install
sudo ldconfig   (<-- important="" is="" p="" this="" very="">

Now for whatever reason the training data isn't installed with this.

download whatever language you need and unzip to /usr/local/share/tessdata folder (requires root permissions)
also download osd traineddata from for example here

try with:
sudo nautilus