map.bern.ch returns PNG tiles when requested JPEG

[habi]

What steps will reproduce the problem?

1. Download data in Bern, Switzerland
2. Load Imagery layer for "Stadt Bern 10cm (2020)": https://josm.openstreetmap.de/wiki/Maps/Switzerland#StadtBern10cm2020

What is the expected result?

Imagery shows up

What happens instead?

The imagery is not loaded, JOSM shows me "Error: HTTP error 200 when loading tiles" instead.

Please provide any additional information below. Attach a screenshot if possible.

Both ID and Go Map!! (​https://wiki.openstreetmap.org/wiki/Go_Map!!) show the imagery just fine, JOSM doesn't.
I'm happy to provide more information on how to debug this and be able to load this imagery in JOSM.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2021-07-12 02:41:41 +0200 (Mon, 12 Jul 2021)
Revision:18004
Build-Date:2021-07-12 00:42:49
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (18004 en) Linux Ubuntu 18.04.5 LTS
Memory Usage: 2508 MB / 30688 MB (342 MB allocated, but free)
Java version: 11.0.11+9-Ubuntu-0ubuntu2.18.04, Ubuntu, OpenJDK 64-Bit Server VM
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Screen: :0.0 1920×1200 (scaling 1.00×1.00) :0.1 1920×1200 (scaling 1.00×1.00)
Maximum Screen Size: 1920×1200
Best cursor sizes: 16×16→16×16, 32×32→32×32
Environment variable LANG: en_US.UTF-8
System property file.encoding: UTF-8
System property sun.jnu.encoding: UTF-8
Locale info: en_US
Numbers with default locale: 1234567890 -> 1234567890
Desktop environment: ubuntu:GNOME
Java package: openjdk-11-jre:amd64-11.0.11+9-0ubuntu2~18.04
Java ATK Wrapper package: libatk-wrapper-java:all-0.33.3-20ubuntu0.1
libcommons-logging-java: libcommons-logging-java:all-1.2-2
fonts-noto: fonts-noto:all-20171026-2
VM arguments: [--add-modules=java.scripting,java.sql, -Djosm.restart=true, -Djava.net.useSystemProxies=true]
Dataset consistency test: No problems found

Plugins:
+ FastDraw (35640)
+ Mapillary (2.0.0-alpha.27-dirty)
+ apache-commons (35524)
+ apache-http (35589)
+ buildings_tools (35756)
+ javafx-unixoid (35655)
+ jaxb (35543)
+ jna (35662)
+ jogl (1.2.3)
+ mapathoner (1.1.9)
+ terracer (35640)
+ undelete (35640)
+ utilsplugin2 (35691)

Map paint styles:
+ https://josm.openstreetmap.de/josmfile?page=Styles/MapWithAI&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Styles/Maxspeed&zip=1

Last errors/warnings:
- 06396.221 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600764.3059784,1198206.3655034,2601070.0540915,1198512.1136165&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png
- 06396.227 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600764.3059784,1198206.3655034,2601070.0540915,1198512.1136165&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png
- 06396.317 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600764.3059784,1197900.6173902,2601070.0540915,1198206.3655034&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png
- 06396.323 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600764.3059784,1197900.6173902,2601070.0540915,1198206.3655034&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png
- 06396.449 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600458.5578652,1198206.3655034,2600764.3059784,1198512.1136165&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png
- 06396.454 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600458.5578652,1198206.3655034,2600764.3059784,1198512.1136165&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png
- 06396.711 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600458.5578652,1197900.6173902,2600764.3059784,1198206.3655034&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png
- 06396.715 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600458.5578652,1197900.6173902,2600764.3059784,1198206.3655034&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png
- 06396.758 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600152.8097521,1197594.8692771,2601375.8022047,1198817.8617297&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png
- 06396.766 W: Image not returned for tile: https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&FORMAT=image/jpeg&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2600152.8097521,1197594.8692771,2601375.8022047,1198817.8617297&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap content type was: png

[habi]

OK, going through the attached information, I see that there seems to be something amiss with the image format that comes from the source.
How can I change/update that there source seems to deliver a PNG while JOSM seems to expect a JPG (?).

[skyper]

Take a look at Maps, respectively Maps/Switzerland for the source.

[stoecker]

Is the issue that the URL contains "&FORMAT=image/jpeg", but the output is PNG? Maybe dropping that parameter is enough (or replace jpeg with png)? JOSM can handle PNG as well (although JPEG is preferred because of the lower bandwidth).

[habi]

Take a look at Maps, respectively Maps/Switzerland for the source

That's what I linked above :)

The 'view' link from that page shows the imagery correctly: https://josm.openstreetmap.de/mapsview?entry=Stadt%20Bern%2010cm%20%282020%29

[habi]

Is the issue that the URL contains "&FORMAT=image/jpeg", but the output is PNG?
Maybe dropping that parameter is enough (or replace jpeg with png)?

I gave it a first try with simply removing the parameter: https://josm.openstreetmap.de/wiki/Maps/Switzerland?action=diff&version=294
How often is such an update 'pulled' into JOSM?
E.g. how long do I have to wait until I can see if the imagery works again?

[stoecker]

The 'view' link from that page shows the imagery correctly

It does probably not check if the "should be" image format matches the "is" format :-)

E.g. how long do I have to wait until I can see if the imagery works again?

Takes some days. Clearing the cache directory should help.

[Don-vip]

Thank you for reporting the issue and editing the wiki!

[Don-vip]

Works fine

2021-07-22 21:00:43.485 INFO: GET https://map.bern.ch/wms/OpenData/proxy.php?LAYERS=luftbild_2020&STYLES=default&CRS=EPSG:2056&WIDTH=512&HEIGHT=512&BBOX=2594037.8474893,1193925.8919194,2596483.8323944,1196371.8768245&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap -> HTTP/1.1 200 (946 ms)
2021-07-22 21:00:43.485 FINE: RESPONSE HEADERS: {Transfer-Encoding=[chunked], Keep-Alive=[timeout=10, max=300], null=[HTTP/1.1 200 OK], Strict-Transport-Security=[max-age=15768000], Server=[Server], Connection=[Keep-Alive], Content-Encoding=[gzip], Vary=[Accept-Encoding], Date=[Thu, 22 Jul 2021 19:00:45 GMT], Content-Type=[image/jpeg]}

Tiles are displayed OK. You can force the update of imagery list from imagery preferences and clear your cache.

[anonymous]

I just checked on another machine, it works fine now.
Thanks for a nice way of submitting an issue, which helped to clear it up :)

[habi]

The comment above was from me, not logged in ;)