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Re: how 2 compress Fat Bitmap

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W dniu wtorek, 28 marca 2017 03:06:23 UTC+2 użytkownik JJ napisał:
> On Mon, 27 Mar 2017 09:13:28 -0700 (PDT), fir wrote: 
> > i get a little big tired when coding roguelike and maybe i could rest
> > coding a side problem 
> > 
> > in my roguelike i use now 24bpp bitmap to store a tile map, it is
> > 2000x2000 pixels (as pixel is something like 'big meter' in game world
> > (something like 1.5 m x 1.5 m) this would be like a 3 km x 3 km square of
> > land 
> > 
> > you could check it packed in 
> > 
> > minddetonator.htw.pl/platform12.zip minddetonator.htw.pl/platform14.zip 
> > 
> > it is 12 MB bmp file and loading it makes 1 second delay at game startup
> > (on my hdd, on some more new hdd could be faster) 
> > 
> > but obviously it could be packed, as i use only come sobset of colors on
> > this map (it would be at most like few thousands of colors/tile types,
> > now i use less than 30) so it may be well packed (it also shopuld be
> > simple to pack as i need only pack raw rectangle of pixels, not other
> > form of data, bitmap header i may skip at all) 
> > 
> > even compressing each pixel into index form - thus reducing 24 bit of
> > color into loke 6-12 bit of index would spare to half or 1/4 of oryginal
> > size.. yet more elaborate ways of compresing (exploring the fact that
> > there are regular patterns of colors not chaotic pixels) could be used
> > (zip packs this 12 MB to 80 kB rar packs 12 MB to 60kB) 
> > 
> > the question is - what algorithm to use to pack it - it could be
> > reasonably simple to write but also maybe something more effective then
> > if i would just turn colors to palette entries? 
> > 
> > what do you think?
> 
> Are you sure that 1 second delay is spent entirely on reading the bitmap
> image? Try using PNG or TIF, instead of BMP. If there's no significant
> difference, it would mean that the image is just too large for the computer
> you use to test your program. e.g. slow CPU or RAM.

im sure

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how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-27 09:13 -0700
  Re: how 2 compress Fat Bitmap JJ <jj4public@vfemail.net> - 2017-03-28 08:06 +0700
    Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-28 00:43 -0700
      Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-28 01:02 -0700
  Re: how 2 compress Fat Bitmap Ed Prochak <edprochak@gmail.com> - 2017-03-28 10:26 -0700
    Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-28 12:19 -0700
      Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-28 12:25 -0700
        Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-28 12:33 -0700
        Re: how 2 compress Fat Bitmap Ed Prochak <edprochak@gmail.com> - 2017-03-30 13:40 -0700
          Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-30 13:50 -0700
            Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-30 13:54 -0700
              Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-30 15:10 -0700
            Re: how 2 compress Fat Bitmap Ed Prochak <edprochak@gmail.com> - 2017-04-03 07:11 -0700
              Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-04-03 08:20 -0700
    Re: how 2 compress Fat Bitmap Robert Wessel <robertwessel2@yahoo.com> - 2017-03-28 16:40 -0500
      Re: how 2 compress Fat Bitmap fir <profesor.fir@gmail.com> - 2017-03-28 15:19 -0700

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