Kdenlive/Manual/Effects/Misc/pr0be
Pr0be
This is a measuremet tool, not an effect. It can show color values of single pixels or statistics of small rectangular areas. It is also useful as a pixel-peeping "loupe".
It can display the following values:
- RGB
- YCC in either rec 601 or rec 709 standards
- HSV
- HSL
The position and size of the measured area is set by the X, Y, Xsize and Ysize parameters. A small crosshair marker is shown in the image, where the measurement is being made.
If "256 scale" is is checked, values are displayed as 0...255 integers, otherwise they are displayed as 0...1 floating point numbers.
If "Show alpha" is checked, alpha channel value are displayed too.
If "Big window" is checked, a bigger area around the center pixel is displayed in the "loupe".
Pr0be can also be used to measure image noise. Just place the meaurement rectangle on an uniform part of the image that contains no image detail, and read the RMS value.
NOTE: the values are displayed with a rather small font, so they might not be readable, if the image is not displayed at a big enough scale (1:1 pixel is optimal)