ETC2 is a widely-used texture compression format in Android devices and applications, so efficient ETC2 encoding can reduce application development time. We present QuickETC2-HQ, a set of improved ETC2 encoding techniques for real-time, high-quality texture compression. Our modifications to the luma-based approximations used in etcpak 1.0, the state-of-the-art encoder which integrated the QuickETC2 method, allow the execution of additional compression modes and more accurate error comparisons. As a result, the image quality of QuickETC2-HQ is improved compared to that of etcpak 1.0 and is comparable to that of the reference encoder, ETCPACK 2.74, with the fast mode. In terms of performance, QuickETC2-HQ is orders of magnitude faster than ETCPACK, making it practical for real-time application execution and offline production builds of applications. Display omitted •A set of improved ETC2 encoding techniques for real-time, high-quality texture compression.•Solving several quality issues appeared in real-time ETC2 encoding (e.g., block artifacts, blurring, posterization, etc.).•Orders of magnitude faster than the reference ETCPACK encoder.