[MS4W-Users] mapcache issues - 3 of 4 images are darker in tiled mode vs single tile mode

[Jeff McKenna]

Hi Mark,

Sorry that no one has replied to you about this yet; possibly because it 
is very difficult to understand your situation without seeing the data 
and your configuration, plus your service doesn't seem to work for me: 
http://10.0.8.113:8080/mapcache/?LAYERS=MurrayPictoPhotos2016&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&FORMAT=image%2Fjpeg&SRS=EPSG%3A103757&BBOX=196060,15222,805060,339722&WIDTH=1218&HEIGHT=649

When you say "converted the air photos to geotiff images and then added 
JPEG overviews" I'm assuming you mean that you used "gdal_translate" to 
create the geotiffs, and then you ran "gdaladdo" to build overviews into 
the geotiffs? The geotiff filesize would increase slightly, and you will 
be able to see a "OVERVIEWS" section in the "gdalinfo" response at the 
commandline.  Maybe it is how you are creating overviews that is the 
problem, possibly.

But if you are stuck, please contact me directly at any time for 
professional support.

Thanks,

-jeff


-- 
Jeff McKenna
MapServer Consulting and Training Services
http://www.gatewaygeomatics.com/



On 2016-06-23 10:27 AM, Mark Volz via MS4W-Users wrote:
> Hello,
>
>
>
>
>
> I am trying to create a mapcache of 2016 air photos for a neighboring
> county.  I was provided 4 Mr SID air photo mosaics.   To increase the
> speed of the mapcache I converted the air photos to geotiff images and
> then added JPEG overviews.  On the mapcache demo site I noticed that the
> single tile mode looks very similar to the original Mr SID air photos –
> which is good.  However, in tiled mode 3 of the 4 images look dark at
> zoomed out at far resolutions.  I could use assistance troubleshooting
> this issue.
>
>
>
> In particular:
>
> ·         Why does the image look fine in single tile mode, but not in
> tiled mode?
>
> ·         Why is it that just a couple zoom levels are bad?
>
> ·         I tried to reprocess the corrupt images.  I am still getting
> the same results.
>
> ·         When I look very close at the single tile mode image, 3 of the
> 4 quadrants are slightly darker than the one quadrant that is working
> right.  These images are also slightly darker in the original sid
> files.  Could it be possible that my source Mr SID files are corrupt?
> But if that is the case then why does the image look okay in single tile
> mode, but not in tiled mode?
>
>
>
> My mapcache is at http://geomoose.lyonco.org/mapcache/demo/wms  The
> services in question are MurrayPictoPhotos2016-MurrayCC-WMS and
> MurrayPictoPhotos2016-MurrayCC-WMS (single Tile)
>
>
>
> Thank You!
>
>
>
> Sincerely,
>
> *Mark Volz, GISP***
>
> *Lyon County GIS Coordinator*
>
>
>
>