[mapserver-users] JPEG and OVERSAMPLE_RATIO

Tue Dec 18 12:04:44 PST 2012

Hi,

Thanks to Thomas, the problem has been solved by removing an OFFSITE
parameter configuring the layer (http://mapserver.org/en/mapfile/layer.html).

With the following layer configuration:
PROCESSING "RESAMPLE=AVERAGE"
PROCESSING "OVERSAMPLE_RATIO=16"
the visual quality of the produced image is very good (for the PNG and JPEG
format).

Best regards,
Cédric

On Mon, Dec 17, 2012 at 5:11 PM, Cédric MOULLET <cedric.moullet at gmail.com>wrote:

> No, we tried with 80 and it doesn't change anything.
>
>
>
> On Mon, Dec 17, 2012 at 5:00 PM, thomas bonfort <thomas.bonfort at gmail.com>wrote:
>
>>
>>
>>
>> On Mon, Dec 17, 2012 at 4:49 PM, Cédric MOULLET <cedric.moullet at gmail.com
>> > wrote:
>>
>>> Hi,
>>>
>>> Output formats:
>>>
>>> OUTPUTFORMAT
>>>   NAME "png"
>>>   MIMETYPE "image/png"
>>>   DRIVER "AGG/PNG"
>>>   EXTENSION "png"
>>>   IMAGEMODE "RGBA"
>>>   TRANSPARENT TRUE
>>>   FORMATOPTION "INTERLACE=OFF"
>>> END
>>>
>>> OUTPUTFORMAT
>>>   NAME jpeg
>>>   DRIVER "AGG/JPEG"
>>>   MIMETYPE "image/jpeg"
>>>   IMAGEMODE RGB
>>>
>>
>>
>>>   FORMATOPTION QUALITY=100
>>>
>> does changing this to values between 80 and 99 change something ?
>>
>>
>>>   EXTENSION "jpg"
>>> END
>>>
>>> URL's:
>>>
>>>
>>> 1.
>>> https://picasaweb.google.com/lh/photo/j_OClw5fGOeQE7K1wiimytMTjNZETYmyPJy0liipFm0?feat=directlink
>>> 2.
>>> https://picasaweb.google.com/lh/photo/3q52h52EwOp9JzZm3KAWbNMTjNZETYmyPJy0liipFm0?feat=directlink
>>> 3.
>>> https://picasaweb.google.com/lh/photo/GTAThw7AOVMK-j-7DWAabtMTjNZETYmyPJy0liipFm0?feat=directlink
>>>
>>> Thanks in advance for your help !
>>> Cédric
>>>
>>>
>>>
>>> On Mon, Dec 17, 2012 at 4:24 PM, thomas bonfort <
>>> thomas.bonfort at gmail.com> wrote:
>>>
>>>> Can you post the outputformats defined in your mapfile, and the urls
>>>> used to access each of these images?
>>>>
>>>> --
>>>> thomas
>>>>
>>>>
>>>> On Mon, Dec 17, 2012 at 4:18 PM, Cédric MOULLET <
>>>> cedric.moullet at gmail.com> wrote:
>>>>
>>>>> I realize that links have been sent and not pictures
>>>>> Here are reachable links for the three cases:
>>>>> 1.
>>>>> https://picasaweb.google.com/lh/photo/j_OClw5fGOeQE7K1wiimytMTjNZETYmyPJy0liipFm0?feat=directlink
>>>>> 2.
>>>>> https://picasaweb.google.com/lh/photo/3q52h52EwOp9JzZm3KAWbNMTjNZETYmyPJy0liipFm0?feat=directlink
>>>>> 3.
>>>>> https://picasaweb.google.com/lh/photo/GTAThw7AOVMK-j-7DWAabtMTjNZETYmyPJy0liipFm0?feat=directlink
>>>>> Cédric
>>>>>
>>>>>
>>>>> On Mon, Dec 17, 2012 at 4:11 PM, Cédric MOULLET <
>>>>> cedric.moullet at gmail.com> wrote:
>>>>>
>>>>>> Hi,
>>>>>> The following issue has been observed with MapServer 6.0.3:
>>>>>>
>>>>>> 1. Very good quality for a PNG with RESAMPLE=BILINEAR and
>>>>>> OVERSAMPLE_RATIO=16:
>>>>>> [image:
>>>>>> http://wms-bgdi.bgdi.admin.ch/?lang=xx&LAYERS=ch.swisstopo.pixelkarte-grau-pk100_bazl&FORMAT=image%2Fpng&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&SRS=EPSG%3A21781&BBOX=513184,143152,519840,149808&WIDTH=256&HEIGHT=256]
>>>>>>
>>>>>> 2. Less good quality for a PNG or JPEG with default resampling
>>>>>> settings:
>>>>>> [image:
>>>>>> http://wms-bgdi.bgdi.admin.ch/?lang=xx&LAYERS=ch.swisstopo.pixelkarte-grau-pk100_original&FORMAT=image%2Fpng&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&SRS=EPSG%3A21781&BBOX=513184,143152,519840,149808&WIDTH=256&HEIGHT=256]
>>>>>>
>>>>>> 3. Awful quality for JPEG with RESAMPLE=BILINEAR and
>>>>>> OVERSAMPLE_RATIO=16:
>>>>>> [image:
>>>>>> http://wms-bgdi.bgdi.admin.ch/?lang=xx&LAYERS=ch.swisstopo.pixelkarte-grau-pk100_bazl&FORMAT=image%2Fjpeg&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&SRS=EPSG%3A21781&BBOX=513184,143152,519840,149808&WIDTH=256&HEIGHT=256]
>>>>>>
>>>>>> Any idea why the OVERSAMPLE_RATIO affects heavily the quality of JPEG
>>>>>> images ?
>>>>>>
>>>>>> Thanks in advance for your help,
>>>>>> Cédric
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Political blog: http://cedricmoullet.blogspot.com/
>>>>> Welcome to my world: http://www.cedricmoullet.com/
>>>>> My Linked In profile: http://www.linkedin.com/in/cedricmoullet
>>>>> Twitter: http://twitter.com/cedricmoullet
>>>>> Home sweet home:
>>>>> http://map.geo.admin.ch/?crosshair=bowl&zoom=11&X=185241.24219&Y=561288.90625&bgOpacity=0&selectedNode=node_ch.swisstopo.fixpunkte-lage1
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> mapserver-users mailing list
>>>>> mapserver-users at lists.osgeo.org
>>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>>>
>>>>>
>>>>
>>>
>>>
>>> --
>>> Political blog: http://cedricmoullet.blogspot.com/
>>> Welcome to my world: http://www.cedricmoullet.com/
>>> My Linked In profile: http://www.linkedin.com/in/cedricmoullet
>>> Twitter: http://twitter.com/cedricmoullet
>>> Home sweet home:
>>> http://map.geo.admin.ch/?crosshair=bowl&zoom=11&X=185241.24219&Y=561288.90625&bgOpacity=0&selectedNode=node_ch.swisstopo.fixpunkte-lage1
>>>
>>>
>>
>
>
> --
> Political blog: http://cedricmoullet.blogspot.com/
> Welcome to my world: http://www.cedricmoullet.com/
> My Linked In profile: http://www.linkedin.com/in/cedricmoullet
> Twitter: http://twitter.com/cedricmoullet
> Home sweet home:
> http://map.geo.admin.ch/?crosshair=bowl&zoom=11&X=185241.24219&Y=561288.90625&bgOpacity=0&selectedNode=node_ch.swisstopo.fixpunkte-lage1
>
>

-- 
Political blog: http://cedricmoullet.blogspot.com/
Welcome to my world: http://www.cedricmoullet.com/
My Linked In profile: http://www.linkedin.com/in/cedricmoullet
Twitter: http://twitter.com/cedricmoullet
Home sweet home:
http://map.geo.admin.ch/?crosshair=bowl&zoom=11&X=185241.24219&Y=561288.90625&bgOpacity=0&selectedNode=node_ch.swisstopo.fixpunkte-lage1
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