Skip to main content

Saving the trees - PDF signatures

How to stick a signature graphic into a PDF file, without having to print it first:

A word of warning first

Don't stick your signature into a MS Word document, since anyone with 2 brain cells can alter it.

Also don't use your usual signature - Make a special scrawl for office use.

Print the file to PDF with Foxit Reader

If the file isn't in PDF format already, open your MS Office document with MS Word on Windows.
Print to a file and select PDF format.

If you cannot print to a PDF, install Foxit Reader: https://www.foxitsoftware.com/products/pdf-reader/

Make a signature graphic with transparent background using Gimp

Make a signature graphic with transparent background:
Take a pen, scrawl on a piece of paper.
Scan it.

Use a real computer - Linux, BSD or Mac:
apt install gimp xournal pdfshuffler

Open the scan file with Gimp
Crop it
Select the white background with the eye dropper
Click Layer, Transparency, Colour to Alpha
Click File, Export, signature.jpg

Annotate the PDF file with Xournal

Open the PDF file with xournal
Click Tools, Image and select the signature.jpg file
Click where you want the signature.
Resize it with the mouse
Click File, Export to PDF and select the original PDF file
Overwrite it.


With xournal, you can annotate a PDF file very nicely.  It is worth learning how to use it.


Comments

Popular posts from this blog

Parasitic Quadrifilar Helical Antenna

This article was reprinted in OSCAR News, March 2018:  http://www.amsat-uk.org If you want to receive Satellite Weather Pictures , then you need a decent antenna, otherwise you will receive more noise than picture. For polar orbit satellites, one needs an antenna with a mushroom shaped radiation pattern .  It needs to have strong gain towards the horizon where the satellites are distant, less gain upwards where they are close and as little as possible downwards, which would be wasted and a source of noise.  Most satellites are spin stabilized and therefore the antenna also needs circular polarization, otherwise the received signal will flutter as the antennas rotate through nulls. The helical antenna, first proposed by Kraus in 1948, is the natural solution to circular polarized satellite communications.  It is a simple twisted wire - there seems to be nothing to it.  Various papers have been published on helix antennas, so the operation is pretty well understood. Therefore,

Weather Satellite Turnstile Antennas for the 2 meter Band

NEC2, 2 m band, 146 MHz, Yagi Turnstile Simulation and Build This article describes a Turnstile Antenna for the 2 meter band, 146 MHz amateur satcom, 137 MHz NOAA and Russian Meteor weather satellites.  Weather satellite reception is described here .  A quadrifilar helical antenna is described here .   Engineering, is the art of making what you need,  from what you can get. Radiation Pattern of the Three Element Yagi-Uda Antenna Once one combine and cross two Yagis, the pattern becomes distinctly twisted. The right hand polarization actually becomes visible in the radiation pattern plot, which I found really cool. Radiation Pattern of Six Element Turnstile Antenna Only a true RF Geek can appreciate the twisted invisible inner beauty of a herring bone antenna... Six Element Turnstile Antenna Essentially, it is three crosses on a stick.  The driven elements are broken in the middle at the drive points.  The other elements can go straight throug

To C or not to C, That is the Question

As most would know, the Kernighan and Ritchie C Programming Language is an improved version of B, which is a simplified version of BCPL, which is derived from ALGOL, which is the Ur computer language that started the whole madness, when Adam needed an operating system for his Abacus, to count Eve's apples in the garden of Eden in Iraq.  The result is that C is my favourite, most hated computer language , which I use for everything. At university, I learned FORTRAN with punch cards on a Sperry-Univac, in order to run SPICE, to simulate an operational amplifier.  Computers rapidly lost their glamour after that era! Nobody taught me C.  I bought the book and figured it out myself. Over time, I wrote a couple of assemblers, a linker-locator, various low level debuggers and schedulers and I even fixed a bug in a C compiler - not because I wanted to, but because I had to, to get the job done!   Much of my software work was down in the weeds with DSP and radio modems ( Synchronization,