AI-Lossless-Zoomer is an open-source .NET tool that utilizes the Real-ESRGAN model provided by Tencent ARC Lab, with a focus on high-quality lossless zooming for portrait and anime images. Key features of the project include support for multi-threaded processing, batch image handling, and robust compatibility with various image formats. This innovative tool is released under the GPL-3.0 license, ensuring its availability for developer modifications and enhancements. With AI-Lossless-Zoomer, users can enjoy precise zooming capabilities while preserving original image details.