<p>White oak (<i>Quercus alba</i> L.) and red oak (<i>Quercus rubra</i> L.) are widely used in high-value wood products, yet their tissue-level differences in dimensional stability remain inadequately quantified. In this specific case, digital image correlation was employed to quantitatively characterized the swelling and shrinking behavior of earlywood and latewood in both species. Full-field strain distributions were computed within successive growth rings, revealing that latewood exhibited greater radial strain than earlywood. Wood rays showed distinctive tangential swelling reaching up to 9.2%. Density was generally the dominant factor governing hygro-deformation; however, in earlywood of white oak, the presence of tyloses increased the apparent density, leading to an overestimation of the density effect on swelling and shrinking. The deformation exhibited pronounced transverse anisotropy in earlywood, whereas latewood exhibited nearly isotropic behavior. A linear relationship between hygro-deformation and moisture content was observed, with no evident swelling hysteresis. The tissue-specific swelling and shrinking coefficients were derived, with radial values of 0.13% in white oak earlywood and 0.09% in red oak earlywood. These findings provide tissue-level insights into how tyloses influence hygro-deformation and have practical implications for applications such as cooperage and furniture production, where precise dimensional stability is critical.</p>