Re: [Gimp-print-devel] HP replies!

[Chema C. <ch...@ce...>]

Dave Hill wrote:
> 
> Interesting. the PCL driver already uses mode 2 (TIFF). I have
> tried mode 9 (CRDR) and it makes it better. I used
> the compression driver written by Martin Lottermoser (sp?) for
> the "hpdj" driver.

If I remember correctly, you are not using Delta Row compression.
I might be completly mistaken !

Delta row (#3) is the best compression in average :

here is a comparison :
   for the testprint3 page.  B&W 300 dpi's
   (NOTE that testprint3 has a pretty big coverage )
   with no compression          :	     1,076,096
   with compression method 2    :	       336,874
   with compression method 3    :		67,290
   with compression method 2&3  :		56,413
   with method 1&2&3 and fixed delta row bug:	53,814
   with blank rows sent as such :		48,379

and there are other speed otimizations, like if you have
test for delta row and the size is 0, look no more and
stuff like that.

Also for color I do delta row with the last row in the same
plane and then test for the row in the previous plane ( for
plane > 1 ) and test for the best size. This is a HUGE diference
when printing in black ( or grays ) objects in color mode.

> 
> I think the trick is to try all the compression schemes and
> dynamically switch to the one giving the shortest output buffer!

Yep. 



> Dave
> 
> --
> Dave Hill, Kempston, Bedford UK         da...@mi...
>                                 davehill at users.sourceforge.net
> Sicth munce ago, I cutn't evun spel enjuneer, and now I are one!