Very slow to scroll geolocalized images

[StephaneP]

What steps will reproduce the problem?

1. Load an image sequence
2. Keep pressing the next image shortcut
3. Compare scrolling speed between Josm latest and tested

What is the expected result?

Scrolling speed should be the same speed for both releases

What happens instead?

With the latest release, it's very slow. Perhaps it's related to #17072 or #20659
See the attached video: At first I was using josm tested, then Josm latest.

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: 2021-04-23 21:32:22 +0200 (Fri, 23 Apr 2021)
Build-Date:2021-04-24 01:30:58
Revision:17814
Relative:URL: ^/trunk

Identification: JOSM/1.5 (17814 en) Windows 10 64-Bit
OS Build number: Windows 10 Pro 2009 (19042)
Memory Usage: 5566 MB / 7218 MB (2602 MB allocated, but free)
Java version: 1.8.0_191-b12, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Look and Feel: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Screen: \Display0 1920×1080 (scaling 1.00×1.00)
Maximum Screen Size: 1920×1080
Best cursor sizes: 16×16→32×32, 32×32→32×32
System property file.encoding: Cp1252
System property sun.jnu.encoding: Cp1252

Plugins:
+ Mapillary (1.5.37.6)
+ OpeningHoursEditor (35640)
+ PicLayer (2a9aa7a)
+ apache-commons (35524)
+ apache-http (35589)
+ areaselector (368)
+ austriaaddresshelper (1597341117)
+ cadastre-fr (35727)
+ continuosDownload (91)
+ contourmerge (v0.1.6)
+ ejml (35458)
+ geotools (35458)
+ javafx-windows (35655)
+ jaxb (35543)
+ jna (35662)
+ jts (35458)
+ log4j (35458)
+ opendata (35640)
+ photo_geotagging (35715)
+ photoadjust (35640)
+ reverter (35732)
+ tageditor (35640)
+ todo (30306)
+ turnlanes-tagging (288)
+ turnrestrictions (35640)
+ undelete (35640)
+ utilsplugin2 (35691)

Tagging presets:
+ %UserProfile%\Documents\Gitlab\preset-josm-collectivites\Presets-collectivités.xml

Map paint styles:
- https://josm.openstreetmap.de/josmfile?page=Styles/Enhanced_Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://raw.githubusercontent.com/species/josm-preset-traffic_sign_direction/master/direction.mapcss
- %UserProfile%\Documents\GitHub\MapCSS-JOSM-Bicycle\cycleway.mapcss

Last errors/warnings:
- 00016.563 E: Failed to locate image 'object--wire-group'
- 00016.672 E: Failed to locate image 'regulatory--dual-lanes-cyclists-and-pedestrians--g1'
- 00017.107 E: Failed to locate image 'regulatory--texts--g1'
- 00017.108 E: Failed to locate image 'regulatory--texts--g2'
- 00017.217 E: Failed to locate image 'void--car-mount'
- 00017.218 E: Failed to locate image 'void--dynamic'
- 00017.219 E: Failed to locate image 'void--ego-vehicle'
- 00017.220 E: Failed to locate image 'void--ground'
- 00017.221 E: Failed to locate image 'void--static'
- 00017.371 E: Failed to locate image 'warning--kangaroo-crossing--g1'