[Officeshots] Pixelwise comparison of pdf files

[Thomas Zander]

On Thursday 16 June 2011 07.08.19 Milos Sramek wrote:
> This way, one can see exactly where are the differences. One can also
> see that some application render the text really poorly.
> 
> Currently I use this tool to prepare a study, which I would like to sent
> to Slovak government as an argument that ODF is the right standard to
> use. I have, however some problems with the officeshots service:

Hey Milos,

I like the idea, at first I was a bit sceptical but the PDF you showed made me 
a believer :)

In comparing output of different pieces of software I often notice that the 
person doing the proof reading gets blind to certain problems.  For instance a 
bug that a certain margin is missing or simply that a bullet it converted into 
a circle.
Because the eye is not that sensitive to subtle problems of this kind I would 
very much like to see this technology used as a helper for detecting such 
problems.

In practice this would mean that the tool has to have a mode where its much 
less sensitive to one or two pixels difference. So that subtle differencs in the 
way that the text is rendered are ignored.
On the other hand it could be much more sensitive to changes that indicate 
whole characters offset.   Essentially;  the more connected pixels are 
different, the stronger the indication of a structural problem.
And such a problem would be very valuable to find since the human eye quickly 
misses those details..

-- 
Thomas Zander