This book starts with an introduction to quantitative texture analysis (QTA), which adopts conventions (active rotations, definition of Euler angles, Wigner D-functions) that conform to those of the present-day mathematics and physics literature. Basic concepts (e.g., orientation; orientation distribution function (ODF), orientation density function, and their relationship) are made precise through their mathematical definition. Parts II and III delve deeper into the mathematical foundations of QTA, where the important role played by group representations is emphasized. Part II includes one chapter on generalized QTA based on the orthogonal group, and Part III one on tensorial Fourier expansion of the ODF and tensorial texture coefficients.  This work will appeal to students and practitioners who appreciate a precise presentation of QTA through a unifying mathematical language, and to researchers who are interested in applications of group representations to texture analysis. Previously published in the Journal of Elasticity, Volume 149, issues 1-2, April, 2022