If you’re looking for on GitHub, you may be confused—because the official tool is not open source and is actually sold on Steam. GitHub does host some third-party wrappers, older versions, or community tools related to it, but not the official release.
Be extremely cautious of any GitHub repository or website claiming to offer a "Free Download" or "Cracked" version of Lossless Scaling. These are often: lossless scaling download github