reading pixel value

Hi everyone
I am using an exemple of segmentation that need a seed point
and I want to manually enter the value,is it possible to read pixel value from an image directly using 3D slicer

These examples should help:

If you have a segmentation method then you can create a plugin for conveniently accessing it from the Segment Editor. See examples here. Most effects use painted seed as input, but some just take a user click, while others markup points.