[wikireader] Images on the WR not so imposible :P [was [wikireader]Error on parsing the spanish wikipedia]

David Garabana Barro david at garabana.com
Tue Nov 3 12:53:53 CET 2009

On Tuesday 03 November 2009 12:15:11 David Reyes Samblas Martinez wrote:
> Regarding compression, I believe lzma is already builded in the
> wikireader application and it compress the images  a 50%. enough for
> start I guess. but I have to recongnize than the image on png looks
> really good do maybe it worth the meaning to implemente it on the
> device if it's not much resource hungr

Both png and pbm are 1 bit images without lossy compression.
You can obtain exactly the same final image quality on both formats, but png 
will have smaller disk size.
Final result only depends on RGB->1 bit indexed conversion method used.

AFAIK png decompression is not resource hungry. Compression *IS*.

PS For minimal png archive size, you *MUST* convert image to 1 bit indexed 
palette before saving it. 
If you use "greyscale", RBG or more than 1 bit palette, png will waste space 
saving palette or RBG/greyscale info.

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