Check out these awesome comparison pictures between the DVD and new Blu Ray release of Giant Robo. They were shared by hissatsu over on Mania.com. His comments from the post...
This is the 4th time I've bought GR (Original LD release, Giant Robo Giga Premium R2 DVD Box, MB R1 DVD release, this BD box). I know the price on the BD box was higher than usual, but try paying more than 10000 yen per LD volume (for some of the volumes). Even with a weaker yen back then, it was pretty damn expensive.
I no longer have the R2 Box to compare to, so the MB R1 release will have to suffice. Though I remember thinking years ago that it wasn't bad. I know bit rate is actually high pretty high (reaching near max for DVD often). Still looks like garbage compared to the BD though. Way too much ringing and the color timing and contrast on the BD is far better.
It appears grain removal was done, though light grain remains, and 90's 35mm film stocks were generally pretty fine-grained to begin with. I can't see any evidence of detail loss, and being a 4K telecine, I'd expect more detail, and it's certainly there. You can often see brush strokes within areas of solid color.
The BD image is slightly wider than 4:3; active image area is 1478x1080 (and screenshots are cropped to that width), so BD screenshots show slightly more image on the left and right edges than the DVD. DVD screenshots bicubic resized to 1440x1080
For the most part they look fantastic. If only I had $375 I was eagar to part with...