[Tilesathome] Empty land tiles

[Frederik Ramm]

Hi,

>  1) Does the t at h client make sure that we really don't upload empty  
> land or sea tiles? I know it checks for black tiles already. Should  
> it for blue/land tiles as well?

It does check for empty tiles but the check is very simple - every  
one of the 256x256 pixels must have exactly one colour. If someone's  
inkscape for some reason outputs a slightly different colour, or if  
there's a near invisible shadow of something in the top-left corner  
or whatever, then empty tile detection doesn't work.

> 2) How can I best identify and delete those tiles? This one is 164  
> bytes large. Is that the smallest size for a 1-color png? should  
> searching for those be sufficient? Or do I need some Image::gd  
> tricks to make sure they have the correct color?

If you ask me: Just identify all level-12 tilesets that have at least  
one tile less than 500 bytes, and then put them all in the render  
queue. (Assuming that the existing tile will be deleted if someone  
uploads an empty tile for it of course. ... or does that require  
RenderFullTileset at the clients then?)

> I am currently counting the number of 164 byte tiles files, but  
> that can take some days :-)

Using mysql or find?

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00.09' E008°23.33'