Fuzzy brushes (was "Ready for 4.8.0-rc1?")

Steve Lime steve.lime at DNR.STATE.MN.US
Tue Jan 3 10:21:42 EST 2006


Try it now. I had a small problem with the trivial (1 pixel wide) case and antialiasing. My test cases run fine now. This should be enough to get single pixel aa lines:

STYLE
  COLOR r g b
  ANTIALIAS TRUE
END

Steve

>>> Sean Gillies <sgillies at FRII.COM> 01/02/06 11:35 PM >>>
Steve,

What about 1-pixel wide antialiases lines? I was trying that out last  
night, but didn't see any effect. Do we have to have width > 2 to get  
antialiasing?

Sean

On Jan 2, 2006, at 9:16 PM, Steve Lime wrote:

> Paul (et al.): I've played around with these a ton recently. I did  
> change =
> the brush creation algorithm to more closely approximate Photoshop  
> or Gimp =
> and the brushes look quite nice. The stair steps still persist at  
> some =
> angles. I'm convinced it is a problem in GD. Brushes w/alpha  
> transparency =
> seem to suffer from aggregation effects of repeated alpha blending.  
> For =
> example, you can create a  circular brush with alpha=3D64 (50%  
> transparent)=
>  and if you draw with it the resulting line is *much* darker than  
> you =
> would expect. This has an unfuzzing effect. As as result the  
> "jaggies" you =
> see in unantialiased lines persist. Off to poke around in GD now.
>
> A work in progress...
>
> Steve
>
>>>> Paul Spencer <pspencer at DMSOLUTIONS.CA> 12/22/05 6:54 AM >>>
> Steve,
>
> I have a question about fuzzy brushes.  Your test case looks really  
> =20
> good.  We tried this on our tiger map file in ka-Map and the  
> results =20
> are less impressive.  It seems to work well for lines that are  
> close =20
> to 45 degrees, but for lines that are closer to the vertical or =20
> horizontal, there is still a noticeable stairstep effect.  Did you =20
> try other angles on the line?  From what you said, my understanding  
> =20
> is that this could be affected by the default hardness that you  
> have =20
> chosen?
>
> Cheers
>
> Paul
>
> On 22-Dec-05, at 12:08 AM, Daniel Morissette wrote:
>
>> Our planned date for 4.8.0rc1 is today (Thursday Dec 22nd). Are we  
>> =20
>> good to go? Did you still have work to do on the fuzzy brushes Steve?
>>
>> Daniel
>> --=20
>> ------------------------------------------------------------
>>  Daniel Morissette               dmorissette at dmsolutions.ca
>>  DM Solutions Group              http://www.dmsolutions.ca/
>> ------------------------------------------------------------
>>
>
> +-----------------------------------------------------------------+
> |Paul Spencer                           pspencer at dmsolutions.ca   |
> +-----------------------------------------------------------------+
> |Applications & Software Development                              |
> |DM Solutions Group Inc                 http://www.dmsolutions.ca/|
> +-----------------------------------------------------------------+

---
Sean Gillies
sgillies at frii dot com
http://zcologia.com/news



More information about the mapserver-dev mailing list