My Personal Technology View

Digital TV is lower quality ?!

We have a normal TV. Slightly old fashioned these days, it uses a glass tube CRT to display the image (i.e. it is not a flatscreen TV). The designers of the TV made a very nice rounded plastic covering, which means you can not use any "set top" addons, i.e. I can't place anything on the TV without it sliding off.

I fixed that by making a nice light weight wooden frame that has 4 legs of different length and skew feet, the end result being a flat horisontal surface on top of the TV, where the Video, DVD, and "Digital Tuner" can be piled, with just a hint of doublesided tape on the feet to avoid it slipping. OK, back to the subject in hand:

The "Digital Tuner" or the DTT unit, converts digital TV signals now being broadcast in my area (Denmark) for a few channels to an analog signal on the SCART kabel for the TV.

Again - technological life has take a step backwards. I now have one more remote, which I use to turn the Digital unit on/off and choose between the 3 channels it delivers. If I use the TV remote to switch channel, nothing happens as the digital SCART signal overrides. Well, it is a passing stage, as the next TV will have this stuff built in.

But - and the reason for this entry - is I am appalled at the digital quality! The good point is that the digital signal is crisp. No "shadows" or echos due to a bounced analog signal. But someone, somewhere was bit skimpy on the number of bits they allocated for the colours. There is lots of "colour banding" The digital coding (compression) is very evident is the dark scenes, night time. You can see a number of squares dancing around in the near-black areas, the squares having one of two different shades of black. The other place where this is visible, is where the picture used is "quiet", it more or less static, and has large areas of similar color (a blue sky f.eks.) You can then see that the digital picture has to choose between two shades of blue, and the boundary becomes evident.

I am quit relaxed about the problem of the digital channel as the signal gets very weak - picture freezes, or portions of t go "Pixelated", as the equivalent analog signal would show a "snowy" picture where the actual signal would be sensed rather than shown. But I am p***** off at the loss of colour quality due to high compression.

Well, I did buy the cheapest decoder I could find, just to taste the new technology, so I will go around an enquire if a more expensive unit does a better decode job, or if these limitaitions are inherit in the supplied signal. If so, I am disappointed. The digital system gets us more channels in the same bandwidth ... by giving us lesser quality (and I am not taking about content here, just the picture quality, dont get me started). OK, ok, I realize that if you want more channels, something has to give, but this is too much.

posted by Msquare @ 3:42 AM