Anti Alias Problem

[Umberto Nicoletti]

On 6/14/06, Thomas Hammerlund <tom at maplink.jp> wrote:
> Thank you for your reply Steve.
>
> I'm running mapserver 4.8.3 and outputting jpegs via the gdal/jpeg driver.
> I'm using the gdal driver because the gd/jpeg driver output progressive
> encoded jpegs(which i couldn't use).
>
> Example layer:
> LAYER
>   NAME l_koku_u
>   STATUS ON
>   TILEINDEX "ixs/shb/50000/l_koku_u_ix"
>   TILEITEM "location"
>   TYPE LINE
>   CLASSITEM Code
> CLASS
>  MAXSCALE 337000
>  MINSCALE 85001
>  Name style1
>  EXPRESSION 'l_bbbcd'
>     STYLE
>       COLOR 240 184 53
>       WIDTH 1
>            #ANTIALIAS TRUE
>     END
>   END
> END
>
> I'm creating my image using perl mapscript.  my mistake, the problem is not
> with the fonts but with the lines.  when I turn style antialiasing on for my
> line layers perl throws an internal server error with no error message from
> mapserver (or perl).
>
> The outputformat in my mapfile looks like this:
>
> OUTPUTFORMAT
> NAME jpeg
> DRIVER "GDAL/JPEG"
> MIMETYPE "image/jpeg"
>  IMAGEMODE RGB
> FORMATOPTION "QUALITY=100"
>  EXTENSION "jpg"
> END
>
> Which antialias patch are you referring to?
>

This one (against gd-2.0.33):
*** gd.c.orig   Wed Jun 14 10:06:22 2006
--- gd.c        Mon Jun 12 12:05:28 2006
***************
*** 3032,3037 ****
--- 3032,3040 ----
  static void gdImageSetAAPixelColor(gdImagePtr im, int x, int y, int
color, int t)
  {
        int dr,dg,db,p,r,g,b;
+       if(x<0||y<0||x>=im->sx||y>=im->sy) {
+               return;
+       }
        p = gdImageGetPixel(im,x,y);
          /* TBB: we have to implement the dont_blend stuff to provide
            the full feature set of the old implementation */

or this one:
http://lists.maptools.org/pipermail/ka-map-users/2006-March/001069.html

The latter is probably better, as it uses a gd macro...

HTH,
Umberto

> Thank you again,
> Tom
>
>
> ----- Original Message -----
> From: "Steve Lime" <Steve.Lime at dnr.state.mn.us>
> To: <MAPSERVER-USERS at LISTS.UMN.EDU>; <tom at MAPLINK.JP>
> Sent: Wednesday, June 14, 2006 2:56 PM
> Subject: Re: [UMN_MAPSERVER-USERS] Anti Alias Problem
>
>
> > Hmmm... I'm suprised turning off style antialiasing would impact font
> > antialiasing.
> > They are totally unrelated.
> >
> > I guess we need a bit more information. What version of MapServer? Has the
> > GD
> > anti-aliasing patch been applied? What output image format?
> >
> > Steve
> >
> >>>> Thomas Hammerlund <tom at MAPLINK.JP> 06/13/06 1:03 AM >>>
> > Hi Everyone,
> >
> > I've been looking for a solution to this, but haven't been successful so
> > far
> > so I'm hoping someone can help.
> >
> > I'm using Fedora 5, and everything I need is working great.  The problem
> > is
> > that when I try the same data set on Fedora 4 or Red Hat Advanced Server,
> > anti alias doesn't work.  The problem can be resolved by commenting out
> > the
> > antialias line, but then it makes my font and lines look too choppy.  Has
> > anyone seen this?  Does anyone know if this is a Linux or a Mapserver
> > problem?
> >
> > Thank you for your help,
> > Tom
> >
> >
> >
>