Complex sentence: Lenna or Lena is the name given to a 512 × 512 pixel standard test image which has been in use since 1973, and was originally cropped from the centerfold of November 1972 issue of "Playboy" magazine.
Split into simpler sentences: Lenna or Lena is the name given to a standard test image which has been in use since 1973. It comprises 512 × 512 pixels, and was originally cropped from the centerfold of November 1972 issue of "Playboy" magazine.