[mapserver-users] Image output issues

[Lime, Steve D (DNR)]

Not sure what version you're working with. In 6.0 it should be as simple as:

  IMAGETYPE GIF
  TRANSPARENT TRUE

No need for any funky output format, just use the default.

Steve

From: mapserver-users-bounces at lists.osgeo.org [mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf Of forums
Sent: Wednesday, December 21, 2011 6:12 AM
To: mapserver-users at lists.osgeo.org
Subject: [mapserver-users] Image output issues

Hi all:

I'm wondering if there's a good solution to the issues I'm having.  I would prefer to use JPEG format for my maps, overall they look better and are smaller.  But I have two issues I'm wondering about.

1) I can't seem to find a way to turn off anti-aliasing. Is it possible to turn it off with JPEG ?  I want the crisper look of aliased lines for the various (MULTI)LINESTRING elements like state/county/country/coastlines, etc.
2) The images are washed out or are lighter in color.  Hard to explain, it's as if it's over exposed film.

If I use GIF output, these problems go away, but other problems are introduced.  For instance the image size goes up too much and the quality of the other features goes down.
I have one of the Nasa Blue Earth images as a base rastar layer, then place roads and other features on top of it.

I can use PNG images, but those are also too large and I still have the antialiasing problem with certain features.

I've considered using a jpeg for the blue marble, then a transparent gif for the overlay, and joining the two.
I can't seem to get the GIF transparency to work though.  (Manually setting the transparency and overlaying the GIF on the JPEG seems to produce a reasonable result.)

Gif declaration:
    OUTPUTFORMAT
        NAME "gif"
        DRIVER GD/GIF
        MIMETYPE "image/gif"
        IMAGEMODE PC256
        EXTENSION "gif"
        FORMATOPTION "TRANSPARENT=ON"
    END
    IMAGECOLOR 55 55 55

Jpeg declaration:
    OUTPUTFORMAT
        NAME "jpeg"
        DRIVER AGG/JPEG
        MIMETYPE "image/jpeg"
        IMAGEMODE RGB
        EXTENSION "jpg"
    END


Can anyone provide any help?

Thank you.



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