This book constitutes the thoroughly refereed post-proceedings of the 4th International Workshop on Graphics Recognition, GREC 2001, held in Kingston, Ontario, Canada, in September 2001 with the sponsorship of IAPR. The 32 revised full papers presented went through two rounds of reviewing and improvement. The papers are organized in topical sections on technical drawings and forms; validation and user interfaces; symbol segmentation and recognition; perceptual organization; map recognition; graphics recognition technology; vectorization and early processing; mathematical notation; charts; and music notation; and arc segmentation contest.