the letter of the image corresponds in short to the first degree of intelligibility (below which the reader would perceive only lines, forms, and colours), but this intelligibility remains virtual by reason of its very poverty, for everyone from a real society always disposes of a knowledge superior to the merely anthropological and perceives more than just the letter.
"Everyone" and "always" are two dangerous words, as most logicians can tell you. One exception disproves the premise, and a diproved premise weakens the argument. The word "real" reveals a bias--what does Barthes mean by a "real" society? It seems, at any rate, a thinly disguised ethnocentric snobbery. "A knowledge superior to the merely anthropological"--why is anthropological knowledge "merely" anthropogical? What, then, is superior to it? and why? I'm not being defensive--I honestly don't know. "Since it is both evictive and sufficient, it will be understood that . . ." "Sufficient"? Sufficient for what? "Evictive"? Does he mean "evocative"? Frankly, I'm not sure anything WILL be understood.
Buy this book for a sleeping pill, a gag gift, or an insufferable class. Otherwise, don't worry about getting literate--in this case, it's overrated. His theories could be expressed in a much simpler way. And then, once you understand them, you find that the ones that do hold up are unquantifiable and inapplicable.