Today I went to Akihabara to buy a printer. Last time I bought one was a long long time ago. I was in Italy and my father bought it for me. In fact, I must have been 16 or so ! It was a Commodore 803, or something like that.
Now, I need to renew my passport, and I really hate the idea of taking one of those lame instant photo-booth pictures. So… yesterday I spent quite a bit of time trying to take a decent shot of my face, and today, I bought a printer.
Anyhow, since there doesn’t seem any decent PDA out there (to me a PDA should be more like a notebook and less like a fat media-center), I think that a printer will be useful for those times in which I want to print some PDF at home, or even a quick map to carry around when going someplace.
Tomorrow I’d like to go to the Italian embassy to renew the passport, but the embassy’s site appears to be down.. so, I have no idea of where this damned embassy is located.
Why is the site down anyway ? Someone must be on strike. In Italy there is always some strike going on. But in this case we are talking about technology (the web.. woohooo !!), so it’s obvious that there is also some other incompetence involved. After all, last time I saw the site, it surely didn’t seem like something very refined (to put it mildly).
About coding.. I’ve been trying to push forward the latest version of RemoteDest, actually now called DSharingu (like the Japanese flavored name ? 8). It’s a complete rewrite. It has come slowly, but it includes a lot of recent stuff that I’ve been doing left and right.. some application-building base code.
My main push in all this is the fact that I want to remotely admin the PCs of my family in Rome, but the provider they use, blocks all ports in input (again, great country and all). That rules out VNC, because it’s based on a server & client architecture by which who shares the PC needs to be able to accept incoming calls on a certain port. In my case, I’m making it possible for my parents to call me and share the display of their PC at the same time.
Another thing that pushes me is, of course, pride ! I’ve been working around this stuff before VNC came out (I think)… I do have something in my hands, it would be lame if I had to give up to some other software.
Speaking of VNC. I did a quick research, and it seems that its compression scheme is not very sophisticated. Apparently it now uses the ZLib and one can choose the compression level based on the ZLib compression level. If VNC’s compression scheme setting relies on the parameter of ZLib, then it means that it’s not that sophisticated.
For example, JPEG images also have a last step of entropy compression. JPEG uses Huffman encoding there, but that really is last step, while the bulk of the compression is somewhere else (transformation to frequency domain and quantization).
I think that there is a lot of room to improve image compression of a GUI display. Many clever things could be done.. and also one should normally deal with lossy compression, because speed is really the main factor when it comes to administer a remote computer.
Currently I’m applying transforming RGB to a luminance + chrominance system, that I simply call YC. It’s simpler than YCrCb, definitely similar to HSL which I’ve been playing with in the past.
One problem with working with RGB with modern displays, is that things such as CoolType and ClearType, juggle around with R, G and B a lot, making it hard to compress them individually.
For the time being I’m posting a screen-shot, although tonight I already successfully set-up a simple installation process using NSIS (great stuff).
And.. 5AM… maybe better go on with a morning of errands and go to sleep in the afternoon !
Posted by Davide Pasca in Image-processing, Programming, Diary