Real-ESRGAN ONNX model assets v1

Reproducible Real-ESRGAN ONNX model assets for Omadesign issue #145.

This is a model-only distribution, not an Omadesign application release. It is excluded from latest and has no application/update archives.

All four models derive from xinntao/Real-ESRGAN official weights (BSD-3-Clause, Copyright (c) 2021 Xintao Wang). BasicSR conversion architecture utilities are Apache-2.0. Full license texts are attached. No Upscayl code or weights are included.

The attached manifest pins original sources, weights, conversion settings, ONNX sizes and SHA-256. Conversion script: https://github.com/michaelmonetized/omadesign/blob/1a232d10/scripts/convert-upscale-models.py

CPU-compatible fp32, ONNX opset 17, NCHW, dynamic spatial dimensions, batch 1. Native x2 requires even input dimensions; Omadesign pads and crops its tiles. The General x4v3 model is embedded in the app; other downloads are optional and verified before installation and every load.