a strip of wood, metal, or stone forming the bottom of a doorway and crossed in entering a house or room.

So that's why I am happy to look at scientology girl, but will never dare cross the threshold and enter the building.

the magnitude or intensity that must be exceeded for a certain reaction, phenomenon, result, or condition to occur or be manifested.

Each text line is partitioned into blocks, and those of which contain a certain threshold percentage of text pixels are identified as valid.