Figure 1. The first appearance of picture element, in a news item in Wireless World and Radio Review, about a demonstration by Ives at Bell Labs of a 50-by-50-element television system.
A few RCA researchers, notably Albert Rose and Otto Schade, continued to use picture element to examine the theory of imaging, but with differing interpretations. Rose wrote in 1946, “A picture element is here taken to be an element of area of arbitrary size, not necessarily the smallest resolvable area.” Schade wrote in 1948, “The smallest detail…which can be resolved by an imaging process…will be defined as a ‘picture element’.” This dual meaning, between an arbitrary element and a resolution element, persists even today with pixel.