Loss of colour detail for downscaled images
Bug report
Upload an image and observe colours for downscaled images.
Steps to reproduce
- Upload Image
- View image in browser
- Compare colours with downloaded original
Expected behaviour
Both images look the same.
Actual behaviour
Some of the colour detail seems to be lost for downscaled images (left side: original downloaded image, right side: downscaled image)

Apparently the jpg files contain a color profile (converted from Canon Raw image using Adobe Lightning (CS?)): http://www.exiv2.org/tags-xmp-crs.html
Server configuration
Server configuration detail
Operating system: Linux 4.13.0-0.bpo.1-amd64 #1 SMP Debian 4.13.13-1~bpo9+1 (2017-11-22) x86_64
Webserver: nginx/1.10.3 (fpm-fcgi)
Database: sqlite3 3.16.2
PHP version: 7.0.19-1 Modules loaded: Core, date, libxml, openssl, pcre, zlib, filter, hash, Reflection, SPL, session, standard, cgi-fcgi, PDO, xml, calendar, ctype, curl, dom, mbstring, fileinfo, ftp, gd, gettext, iconv, igbinary, json, exif, pdo_pgsql, pdo_sqlite, pgsql, Phar, posix, readline, redis, shmop, SimpleXML, sockets, sqlite3, sysvmsg, sysvsem, sysvshm, tokenizer, wddx, xmlreader, xmlwriter, xsl, zip, Zend OPcache
Nextcloud version: 12.0.4 - 12.0.4.3
Updated from an older Nextcloud/ownCloud or fresh install: updated from older 12.0.x
Where did you install Nextcloud from: manual install
Signing status
Array
List of activated apps
Enabled:
- activity: 2.5.2
- bruteforcesettings: 1.0.3
- calendar: 1.5.7
- comments: 1.2.0
- dav: 1.3.0
- deck: 0.2.8
- federatedfilesharing: 1.2.0
- federation: 1.2.0
- files: 1.7.2
- files_pdfviewer: 1.1.1
- files_sharing: 1.4.0
- files_texteditor: 2.4.1
- files_trashbin: 1.2.0
- files_versions: 1.5.0
- files_videoplayer: 1.1.0
- firstrunwizard: 2.1
- gallery: 17.0.0
- issuetemplate: 0.3.0
- logreader: 2.0.0
- lookup_server_connector: 1.0.0
- metadata: 0.6.0
- nextcloud_announcements: 1.1
- notifications: 2.0.0
- oauth2: 1.0.5
- password_policy: 1.2.2
- provisioning_api: 1.2.0
- serverinfo: 1.2.0
- sharebymail: 1.2.0
- survey_client: 1.0.0
- systemtags: 1.2.0
- theming: 1.3.0
- twofactor_backupcodes: 1.1.1
- twofactor_u2f: 1.4.0
- updatenotification: 1.2.0
- workflowengine: 1.2.0
Disabled:
- admin_audit
- encryption
- files_external
- user_external
- user_ldap
Configuration (config/config.php)
{
"instanceid": "oc5b2vj7qs8s",
"passwordsalt": "***REMOVED SENSITIVE VALUE***",
"secret": "***REMOVED SENSITIVE VALUE***",
"trusted_domains": [
"XXX",
"qnap.local"
],
"datadirectory": "\/srv\/nextcloud\/data",
"overwrite.cli.url": "XXX",
"dbtype": "sqlite3",
"version": "12.0.4.3",
"installed": true,
"maintenance": false,
"theme": "",
"loglevel": 2,
"updater.release.channel": "stable",
"memcache.local": "\\OC\\Memcache\\Redis",
"memcache.locking": "\\OC\\Memcache\\Redis",
"redis": {
"host": "\/var\/run\/redis\/redis.sock",
"port": 0
}
}
Are you using encryption: no
Client configuration
Browser: Firefox/Chrome/Safari
Operating system: Fedora 27 / Mac OS X High Sierra / Android 7
I confirm I have the same issue on NextCloud 13.0.2. Switching the color profile (when exporting from LightRoom) from ProPhoto RGB to sRGB fixed the rendering problem for me.
Confirming that sRGB works better :)
Still the same problem with nextcloud 17. Does anyone know a workaround (that doesn't involve changing the images)?