Is there a dif filter that will dump to a file?

[FredThompson]

I've seen difference filters that will report which difference characteristics to the display.

Not quite what I'm looking for. I'd like to scan an entire stream and know where there are major differences. In this case, the entire stream is assumed to be a static image.

Many possible uses: tape integrity test, surveillance camera footage, analysis of time-lapse or high-speed footage, probably other uses as well.

Does such a filter exist?

[Guest]

Two of my filters may be of interest to you.

1. Multidecimate() (pass=1) generates a file called mfile.txt that contains difference metrics for each frame compared to its predecessor. The difference metric is frame-global. Get it here:

http://shelob.mordor.net/dgraft/misc/multidecimate103.zip

2. Dup() with copy=false and debug=true will send difference metrics to the DebugView utility, which has log file capability that will allow collection of the metrics into a file. The difference metric is the biggest difference of 32x32 windows on the frame. Get it here:

http://shelob.mordor.net/dgraft/dup/dup220b1.zip

[FredThompson]

Yeah, I was looking at your Dup filter again last night but missed how to send the status to a file. Will it dump for every frame or is this a function of the threshold parameter?

[Guest]

Every frame's metric is sent to the DebugView utility.

[FredThompson]

Ick, well, I'll give it a shot.

An hour will be over 113,000 metrics.

[Guest]

So your log will be a couple of meg. So what?

Even a Basic (pun intended) programmer could write a postprocessor to return only the entries exceeding a desired threshold. :)

[FredThompson]

Ouch.

Yeah, actually I realized that after a while. My first thought was to load the log into Word. Don't think that'd work too well.

Yeah, a simple line-oriented scan would be easy...

[WarpEnterprises]

MS Access works well, too for those things and you can combine it with VBA functions...

[Guest]

You could write a PERL script in, oh, 5 minutes.

[WarpEnterprises]

Now I am curious:
What's PERL?
Do you have some links at hand and on what platform does it run?

[Richard Berg]

Everything, basically. http://www.google.com/search?cat=&q=perl

[FredThompson]

There's also Python or if you REALLY wanted to get exotic, Squeek.

(Sniff...sniff...smells like Slashdot...)

[Guest]

Originally posted by WarpEnterprises
Now I am curious:
What's PERL?
Do you have some links at hand and on what platform does it run? PERL = Pattern Extraction and Reporting Language

I use the free PERL from ActiveState:

http://www.activestate.com/Products/ActivePerl/

It is available for Windows, Solaris, and Linux.