1080p 'dot by dot' mode - what on earth else?
Here is a quote describing a feature on a television (a Pioneer Kuro 1080p model to be specific).
"Other attractions include a 'dot by dot' mode that removes overscanning for perfect transposition of Blu-ray and HD DVD material to the TV's 1920 x 1080 panel"
Could someone from the What Hi-fi review team please explain to me why a tv would need to have this 'dot by dot' mode on its list of features? I mean, surely this is the obvious way that a tv should work; a signal that exactly matches the screen's resolution is correctly mapped onto the screen, with each pixel from the source being mapped to it's corresponding pixel on screen - hence the 'dot by dot' (pixel by pixel) tag.
And what is this 'overscanning' that is mentioned? Does this mean that normally (on a 1080p tv without a 'dot by dot' mode) the 1080p signal is downscaled then upscaled again a few times just for the sake of it? What else could it mean?
Can someone from the team put my mind to rest, and explain this to me, as would be much appreciated.
Many TVs have picture processing modes designed to "improve" picture quality in various ways (better handling of fast motion, dark scenes etc.).
The "dot by dot" or "1:1 pixel mapping" modes will bypass these picture processing modes giving a picture which is closest to the source.
It's like the video equivalent of the "anologue direct" mode found on some amplifiers which avoid using unneccesary digital processing on non-digital signals.