Measurement Frei0r plugins
Plugins for various measurements on video
Included are the following plugins:
Pr0be Measure channel values, with statistics
Pr0file a 2D video oscilloscope with readouts
Written by Marko Cebokli, jun 2010, and released under GNU GPL
RELEASE NOTES
** jun 2010
Version 0.1
"pre-alpha" (throw it out and see what happens... :-)
INTRODUCTION
I am an old engineer, who is not happy unless surrounded by ...scopes,
...meters, ...lyzers and stuff. So I had to do this, really.
I suspect these plugins won't be of much use for the general public
(well, the geeky types might like them anyway ;-).
They are intended mainly for developers and testers.
NOTE1: The "test_pat_*" plugins can provide well defined signals for
stimulus/response measurements.
NOTE2: for best results, watch the output on 1:1 pixel scale display.
****** DESCRIPTIONS OF EACH PLUGIN FOLLOW ******
PR0BE
Uses a variable sized probe, that can be moved across the image to
sample values of the color channels. Comes with a magnifier for pixel
accurate work, and does statistics over the probe area. It is useful
mainly for checking color and levels.
parameters:
Measurement select the set of channels to measure
X X position of probe
Y Y position of probe
X size X size of probe
Y size Y size of probe
256 scale Show values as 0-255 instead of 0.0-1.0
Show alpha Show the values of the alpha channel too
Big window Display a bigger info window
The available channel sets are RGB, two flavors of Y'PrPb, HSV and HSL.
HSV and HSL are strange nonlinear combinations, not very scientific, so
the statistics are not displayed for them.
Avg is the average value within the probe rectangle. RMS is the "AC"
component. For example, it can be used to measure noise, when the probe
is placed over an otherwise uniform area.
PR0FILE
A classic scope can show you a line waveform, and maybe a vertical
profile too. This one can show profiles at any angle anywhere in the
image, so I call it a "2D scope". It has two markers with delta and a
profile statistics display. It has a zillion parameters, but if you've
been to a lab lately, you probably noticed that any self respecting
'scope' is replete with buttons and knobs :-)
The main purpose of "pr0file" is to measure spatial impulse and step
responses, chroma delays, noise, etc.
parameters:
X X position of center of profile
Y Y position of center of profile
Tilt The angle of the profile
Length The length of the profile
Channel The color channel to display numnerically
Marker 1 Position of first marker along the profile
Marker 1 Position of second marker along the profile
R trace Turn on trace of R channel
G trace Turn on trace of G channel
B trace Turn on trace of B channel
Y trace Turn on trace of Y channel
Pr trace Turn on trace of Pr channel
Pb trace Turn on trace of Pb channel
Alpha trace Turn on trace of alpha channel
Display average Turn on numeric display of profile average
Display RMS Turn on numeric display of profile RMS (AC value)
Display minimum Turn on numeric display of profile minimum
Display maximum Turn on numeric display of profile maximum
256 scale Show values as 0-255 instead of 0.0-1.0
Color Select rec 601 or rec 709 for Y'PrPb calculation
Crosshair color Select one of 8 colors for the profile marker, to make
it stand out from different image contents.
The markers are switched on by pulling them from the leftmost position,
and turned off by slamming them all the way left. When a marker is
activated, a numeric display of its value is automatically turned on.
When both markers are active, a difference display appears.