[mkgmap-dev] [PATCH v1] Optimize filters for shapes

Fri Jan 18 20:22:20 GMT 2013

Hi WanMil,

WanMil wrote
> Reducing the img file size is a nice subeffect. As long as I don't know 
> for sure that spikes are not an error I would avoid to leave them in the 
> img.

I've analysed the filters a bit more. It seems that it is better to 
let DouglasPeuckerFilter "see" the data that RoundCoordsFilter
produces (including spikes)
Ive coded a new filter that can be used to filter spikes and 
and points on straight lines, see attached patch.
It reduces img size a little bit, but also increases run time a little bit.
It is able to find obsolete points on diagonal lines, maybe that is
not really needed because I only see them on vertical and horizontal lines.

Gerd 

filter_shapes_v1.patch
<http://gis.19327.n5.nabble.com/file/n5745401/filter_shapes_v1.patch>  

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