Configuring MapServer .MAP files to return non-interlaced PNGs
To MetaTile and return PNG (non interlaced) the OUTPUTFORMAT needs to be as follows:
IMAGETYPE png OUTPUTFORMAT NAME png DRIVER AGG/PNG IMAGEMODE RGB MIMETYPE "image/png" EXTENSION "png" FORMATOPTION "INTERLACE=OFF" END
Normally the following definition is used for base.map (i.e. overlays)
MAXSIZE 8192 IMAGETYPE AGG_Q OUTPUTFORMAT NAME 'AGG_Q' DRIVER AGG/PNG IMAGEMODE RGBA FORMATOPTION "TRANSPARENT=OFF" FORMATOPTION "QUANTIZE_NEW=ON" FORMATOPTION "QUANTIZE_COLORS=256" FORMATOPTION "interlace=off" END