IS AN ARTIST'S fame likely to survive him? Or her? For innoI vative titans like Picasso, the answer is inevitably yes; for the rest, probably no, the art museums and the law of supply and demand being the ultimate arbiters.

But opportunities for posthumous fame do present themselves--sometimes through the dogged efforts of friends, sometimes as the result of new market demands. Revivals in each category are currently under way locally: Victor Hammer (1882-1967) at the Athenaeum in Alexandria and Ruth Anderson (1891-1957) at the Dent Collection in Northwest Washington. Both artists deserve the fresh exposure they have been given. Neither deserves oblivion.

Born a century ago in Vienna and classically trained at the Academy there, Victor Hammer is the most extraordinary of the two. Painter, sculptor, draftsman and printmaker, he had a considerable reputation as a portraitist and printer of fine editions when he came to teach at Wells College in the wake of Nazi rejection of his work in 1939. By the time of his death in 1967, he had reestablished himself and his press at Transylvania University in Lexington, Ky., and his mezzotints and books (for which he designed and cut his own uncial fonts) were widely collected. Several examples purchased by Lessing Rosenwald have since entered the collections of the Library of Congress and the National Gallery of Art. It was Hammer's book-collecting friends--notably Herbert Sanborn, retired exhibits officer at the Library of Congress--who insisted this centennial show take place.

But it is Hammer's splendid portraits of the rich European and American intelligentsia that come as such a stunning surprise. A large portrait of Edgar Kaufmann (the Pittsburgh businessman who commissioned Frank Lloyd Wright to build "Falling Water") is typical: Rendered in meticulous detail in the difficult medium of egg tempera, it has a crispness and clarity of line, a timeless quality that harks back to the look and mood of early Florentine portraits.

Yet there is also a psychological penetration that is riveting, both here and in other images, such as that of Mrs. Coleman Johnston (1952), who wears a necklace of braided gold, built up in gesso and covered with gold leaf. Decisively un-modern, these works--though exhibited at the Carnegie Museum in Pittsburgh and the Corcoran here--must have seemed old-fashioned when they were made. Yet today--timeless, classic, remote from the vagaries of everyday life--these works are exceptionally fresh. The best of them, in fact, are among the finest 20th-century painted portraits this viewer has seen.

Hammer also painted religious allegories, but the examples on view--some of them unfinished--do not represent the artist's highest achievement. Lovers of graphic arts will find satisfaction in several fine portraits in mezzotint as well as 22 books designed and printed by Hammer. A master calligrapher, Hammer often painted lettering into his portraits, adding to their classic appearance. At 3 Sunday, at the Athenaeum, John Michael, owner of the Acorn Press, Rockville, will give a public talk on Hammer. This exhibition--Hammer's first since his 1965 retrospective at the North Carolina Museum of Art--continues through June 11. It is open Tuesday through Saturday, 1 to 5, at 201 Prince St. in Alexandria.

When the proprietors of the Dent Collection first called the Pennsylvania Academy to check out some recently acquired paintings by alumna Ruth Anderson (b. Carlisle, Pa., 1891), they were told there were none. A mere four months later, with the help of the Academy and judiciously placed ads, proprietors Joyce and Henry Farr have managed to produce the largest Anderson show since the artist's death in 1957. The 59 loosely brushed portraits and impressionistic scenes of Wall Street, Beacon Hill, Gloucester and points in Europe take an important step toward explaining Anderson's seemingly happy life in art.

Her portraits of rosy-cheeked children of the well-to-do first attracted the public to her work, and this show affirms that the best of them remain her strongest work. Trained under impressionist William Merritt Chase, Anderson also bears the strong influences of her classmates, "Ashcan School" painters-to-be Robert Henri, John Sloan and William Glackens. Anderson had her first solo at the Baltimore Museum of Art at age 25, and showed in several Corcoran Biennials, as well as at Vose Gallery in Boston. The show continues through June, and is open Tuesday through Saturday, 1 to 5, at 5232 44th St. NW.