Hi Paul,
The differences among the image types in the RGB image pipeline typically involve various processing stages, including compression and filtering. The artifacts you're observing could indeed be applied during the "Image Post-Processing" module.
To mitigate these issues and achieve the desired image quality, you can experiment with manipulating the filters in the ISP or Image Post Processing module. Adjusting settings such as sharpness, luma denoise, and chroma denoise might help preserve fine-scale details for that check Image quality comparison — DepthAI Hardware Documentation 1.0.0 documentation (luxonis.com) and every third-party application such as https://jpegcompressor.com/. They maintain the quality as well as sharpness, luma denoise, and chroma denoise.