Game CG included inside the game “夏有天狼 (Sirius Summer)”, nearly all images were originally in 1280×720 size, which is quite small.
The latest Real-ESRGAN image restoration model was used to upscale (4.0x, as the training model was designed for) and restore (denoise, restore details) the images.
It took Real-ESRGAN around 2 hours to crunch down all 250 images on my machine (Small input, shorter time).
All uploaded pics were compressed with PNG compression level 9.
Mega Link: {Torrent available, cloud drive full, link discontinued.}
Feel free to re-upload the whole archive elsewhere then share the link, since I'm not sure how long it would stay up in my cloud drive.
Pictures in the archive were compressed using WebP in lossless mode for maximum disk space utilization (nearly 40% reduction compare to PNG with no information loss).
You can use many free image converters to convert them into any file types you like with no quality degradation, I personally like to use XnConvert.
You can also look at them as is, using image viewers like ImageGlass and XnView.