TV ScreenTest Patterns

[ukb007]

Hi folks.

Can you tell me where I can download those Test Patterns - the ones that show you by means of colored squares and circles whether your TV's vertical and horizontal aspects are correct and whether there are any distortions or not ?

Thanks.

[bilu]

Make one yourself :)

http://www.avisynth.org/index.php?page=ColorBars


Bilu

[ukb007]

Thanks, Mr Bilu. I've visited the link. Proved to me conclusively that I am just collecting pebbles by the seashore of knowledge. I can't say that the colorbars page provided a lot of illumination. Sorry. But maybe you can be more specific as to how I can make a tesat pattern myself. A few more lines, please?

I understand that I am in the midst of real pros in these fora, but that's how one learns. Thanks.

[bilu]

I don't know if you know Avisynth already, so here it goes:

Avisynth is a frameserver. You can create a text file with a script in the Avisynth language, requesting external filters when necessary, and rename it to filename.avs . Then calling this file through a media player or encoding application would make Avisynth "render" the script file in the form of a fake AVI. It's still filename.avs ,but to the player it has an internal structure of an AVI.

In this example you just need to install Avisynth, create a script called something.avs, insert into the script the line

ColorBars(640,480)

and serve it to your encoding application. And voilá! :)


Bilu

[r6d2]

Those B&W squares and circles to test AR and brightness/contrast would be a nice to have too, and I have not found an AviSynth function to do that. Any ideas?

[bilu]

Only found this

http://www.avisynth.org/index.php?page=LayerLoop

But it's better if a moderator moves this thread to Avisynth Usage.


Bilu

[Wilbert]

Plotting squares and circles is possible in AviSynth:

http://forum.doom9.org/showthread.php?s=&threadid=44894

[r6d2]

Thanks, but I did not mean literally circles and squares, sorry for not being precise enough.

I meant the "standard" B&W chart display used in TV stations to test the broadcast and tune the TVs. With it (IIRC) you can measure overscan, contrast, brightness, even pitch I guess.

Anybody remembers it? Is is 30 or more years old...

[bilu]

But you can already use circles on top of the color bars and make the standard screen yourself, as Wilbert said.

Bilu

[Richard Berg]

I know the chart you're talking about. There are circles in the center to test geometry, and graduated black bars on the horizontal and vertical edges to test frequency response. Unfortunately describing that diagram mathematically (or more to the point, programmatically) would be a nightmare, so my suggestion would be to find a .gif or .png of it and load via ImageReader. In fact, if you can find a link, I'd love to have a copy.

[r6d2]

Originally posted by Richard Berg
In fact, if you can find a link, I'd love to have a copy.
That makes two of us :). I've searched a lot without luck (difficult to state a search, though).

Rest assured that if I find it I'll post it. I still hope some people here have a clue on where to find it though.

[Tri]

Here are some:

http://www.gpsa.co.za/sa/jokes/nuwe_toets.jpg
http://www.meldrum.co.uk/mhp/testcard/around_world.html

Edit:
And some more:

http://www.069tv.de/images/testbild2.jpg
http://www.tv-testbild.com/Monatsbilder/022002_studio_lu.jpg
http://www.tv-testbild.com/Monatsbilder/07_tab.jpg
http://www.tv-testbild.com/072002/bayern.jpg
http://www.tv-testbild.com/Monatsbilder/mb05.jpg

Google finds a lot of them on www.tv-testbild.com

[BruceL]

Check out "TestBeeld" by Peter den Bak.
It's a pretty cool freeware program that allows you to change and adjust test patterns. You can find it at the web address below.

http://home.worldonline.nl/~peterdb/testcard/