Yama no Susume series has outstanding sakuga, and is loved by many of our group members. Unfortunately the Blu-ray quality is not very good, and rather messy in terms of production. The whole series appeared to have 720p native resolution, and were upscaled using two different low quality algorithms, such that some of the shots have relatively coarse and weak aliasing, and seem blurry overall; while other shots have fuzzy edges, together with fairly strong ringing, makes the picture very sharp overall.
To make matters worse, these two kinds of visually distinct shots are intermingled in most of the episodes in S1 and S3. Moreover, there are many obvious banded scenes in S1 and S3, especially in S1. On top of all this, the bonus content also has various common issues found in interlaced videos.
We tried to fix these problems accordingly, first analyzed and determined upscaling algorithms for each single shots across all episodes, trimmed as necessary, de-scaled correspondingly back to 720p, and upscaled everything with high quality algorithm, followed up with other AA and de-ringing filters to clean up the residual aliasing and ringing, to make the visual appearance consistent throughout the whole series. We also used strong smoothing kernel to clean up the stubborn banding found in S1 and S3.