Antialias JOSM logo on loading screen - jaggy steps are not very nice

[mkoniecz]

What steps will reproduce the problem?

1. Open JOSM
2. See logo

What is the expected result?

No jaggy steps on upper logo edge

What happens instead?

Jaggy steps especially visible on the upper edge

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

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2019-09-12 23:23:47 +0200 (Thu, 12 Sep 2019)
Build-Date:2019-09-12 21:28:35
Revision:15348
Relative:URL: ^/trunk

Identification: JOSM/1.5 (15348 en) Linux Ubuntu 16.04.6 LTS
Memory Usage: 428 MB / 869 MB (183 MB allocated, but free)
Java version: 1.8.0_201-b09, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: :0.0 1366x768
Maximum Screen Size: 1366x768
libcommons-logging-java: libcommons-logging-java:all-1.2-1+build1
fonts-noto: fonts-noto:-

Plugins:
+ OpeningHoursEditor (34977)
+ PicLayer (35104)
+ buildings_tools (34982)
+ continuosDownload (82)
+ ejml (35049)
+ geotools (34908)
+ imagery_offset_db (34908)
+ jts (35064)
+ log4j (34908)
+ measurement (35051)
+ reverter (35084)
+ todo (30306)

Validator rules:
+ ${HOME}/Documents/install_moje/OSM software/josm/data/validator/deprecated.mapcss
+ ${HOME}/Documents/install_moje/OSM software/josm/data/validator/unnecessary.mapcss
+ ${HOME}/Documents/install_moje/OSM software/josm/data/validator/combinations.mapcss

Last errors/warnings:
- W: No configuration settings found.  Using hardcoded default values for all pools.
- W: Failed to add ${HOME}/Documents/install_moje/OSM software/josm/data/validator/deprecated.mapcss to tag checker
- W: java.nio.file.NoSuchFileException: ${HOME}/Documents/install_moje/OSM software/josm/data/validator/deprecated.mapcss
- W: Failed to add ${HOME}/Documents/install_moje/OSM software/josm/data/validator/unnecessary.mapcss to tag checker
- W: java.nio.file.NoSuchFileException: ${HOME}/Documents/install_moje/OSM software/josm/data/validator/unnecessary.mapcss
- W: Failed to add ${HOME}/Documents/install_moje/OSM software/josm/data/validator/combinations.mapcss to tag checker
- W: java.nio.file.NoSuchFileException: ${HOME}/Documents/install_moje/OSM software/josm/data/validator/combinations.mapcss