Kyle - I was looking at images like this one:
http://maps.kylemulka.com/imagemagick/floorplans/tiles/dude-1-1-5.png The image itself is indeed 256x256, but your MapServer WMS request is asking for a source area much larger than 256x256 to be rendered into a 256x256 image. The image quality degradation is coming from asking MapServer to resample the source images to a lower output resolution. You can get better quality resampling by using a (slower) tool to preprocess the images. - Ed Ed McNierney President and Chief Mapmaker TopoZone.com / Maps a la carte, Inc. 73 Princeton Street, Suite 305 North Chelmsford, MA 01863 Phone: +1 (978) 251-4242 Fax: +1 (978) 251-1396 [EMAIL PROTECTED] -----Original Message----- From: UMN MapServer Users List [mailto:[EMAIL PROTECTED] On Behalf Of Kyle Mulka Sent: Tuesday, April 04, 2006 2:09 AM To: [email protected] Subject: Re: [UMN_MAPSERVER-USERS] Increase Clarity of WMS I'm pretty sure that all the tile images are in fact 256x256 and are being rended that way by the browser. Do have a specific example of one that's not like? Either generated by the javascript, or a tile in that folder? Tools->Page Info->Media in Firefox will tell you what images are currently loaded, including those loaded dynamically with javascript. I'm thinking that I might have to use Google Maps itself to do georeferencing. That way I can limit, or even eliminate the amount of scaling and resampling that mapserver has to do. I'll give it a try next week when I have some time. If someone has already done some georeferencing with Google Maps and mapsever, let me know. Thanks, -Kyle Ed McNierney wrote: >Kyle - > >Well, if you increase the WIDTH and HEIGHT to 512 it will certainly >look better - and larger! > >You are taking a relatively large image and asking MapServer to shrink >it down for you for display. I haven't time to decipher all the >JavaScript in there, but I suspect your "simply chopping up tiles using >ImageMagick" example is actually generating HTML that tells the client >browser to stuff an oversized PNG into a smaller IMG tag. Your >individual image tiles (from the floorplans/tiles/ directory) are >actually much larger images than your >http://maps.kylemulka.com/imagemagick/livedude.php displays. Each >individual tile is 512x512 pixels, but your final output image is much >smaller than that. > >As a result, the quality of the output image may depend heavily on the >browser being used. I think those 512x512 tiles are being displayed in >IMG tags with HEIGHT and WIDTH properties set to a smaller value. The >browser then squishes the images into the IMG space available. > >The image you're using is almost a worst-case scenario for MapServer. >It's essentially a vector drawing that's been scanned as a raster image. >You've got lots of thin lines that easily appear and disappear at >different scale levels, depending on how the image is resampled. > >If you're going to use scanned line art in MapServer, you'll get the >best results by producing high-quality resampled versions (ImageMagick >is fine) at each specific scale/zoom level you'll want to use. Then >force the user to only use one of your preselected zoom levels. Make >sure that each image - when displayed - ends up exactly the same size >as the original image on your server. > > - Ed > >Ed McNierney >President and Chief Mapmaker >TopoZone.com / Maps a la carte, Inc. >73 Princeton Street, Suite 305 >North Chelmsford, MA 01863 >[EMAIL PROTECTED] >(978) 251-4242 > >-----Original Message----- >From: UMN MapServer Users List [mailto:[EMAIL PROTECTED] >On Behalf Of Kyle Mulka >Sent: Monday, April 03, 2006 7:30 AM >To: [email protected] >Subject: Re: [UMN_MAPSERVER-USERS] Increase Clarity of WMS > >Here's one of the WMS tiles I'm using. I've tried stretching it using >different values for the height and width but nothing I've tried has >made it look better or worse. >http://kylemulka.com/cgi-bin/mapserv?map=floorplans.map&REQUEST=GetMap&; >S >ERVICE=WMS&VERSION=1.1.1&LAYERS=dude-1&STYLES=&BGCOLOR=0xFFFFFF&TRANSPA >R >ENT=TRUE&SRS=EPSG:4326&BBOX=-83.7158203125,42.2905166207974,-83.7144470 >2 >148438,42.291532494305976&WIDTH=256&HEIGHT=256 > >-Kyle > >Josh Livni wrote: > > >>Kyle, >> >>I could be wrong -- I haven't used a mapserver wms in Google Maps - >>but I think your mapserver image may be being squashed a bit. It's a >>bit less wide relative to the height/width of your Imagemagick >>version. Also the gmap div seems to be a different height/width in the >> >> > > > >>different versions. >> >>WMS will happily respond with the exact extent, but perhaps not the >>relative height/width you expect, thus 'squashing' the image, which >>may be causing the image issues you're seeing. >> >>You may want to play with this by adding a &height &width to the wms >>query, or you could try playing with the div height/width ratios, and >>seeing if you get similar results if one is a bit off, as I may be >>off-base with this theory. >> >> -Josh >> >>Kyle Mulka wrote: >> >> >> >>>I have these very detailed floor plans that I'd like to georeference >>>and display through mapserver's WMS sever, however, the clarity of >>>the images degrades when it goes through. How can I increase the >>>clarity of these floorplans through the WMS? >>> >>>Here's with mapserver: >>>http://maps.kylemulka.com/floorplan-test10.php >>> >>>Here's without (simply chopping up tiles using Imagemagick) >>>http://maps.kylemulka.com/imagemagick/livedude.php >>> >>>Here's the parts of the map file for just the first floor: >>>MAP >>>NAME "UofM" >>> FONTSET fontset.txt >>> PROJECTION >>> "init=epsg:4326" >>> END >>>IMAGETYPE png24 >>>EXTENT -83.747063 42.272038 -83.709126 42.297056 SHAPEPATH >>>"/umdata/" >>>LAYER >>> NAME "dude-1" >>> TYPE raster >>> DATA "dude1.tif" >>> PROCESSING "RESAMPLE=AVERAGE" >>> PROCESSING "DITHER=YES" >>> METADATA >>> "wms_title" "dude-1" >>> "wms_onlineresource" >>>"http://kylemulka.com/cgi-bin/mapserv?map=floorplans.map&"; >>> "wms_srs" "EPSG:4326" >>> END >>> STATUS ON >>>END >>>END >>> >>>-Kyle >>> >>> >> >> >> >> >> > > > >
