Hi!  Following a thread on GitHub regarding the jpeg_quality setting of the previewgenerator app.  I found that the jpeg_quality setting is not used by Nextcloud (files/gallery) itself, so if you do not use the previewgenerator, all thumbnails and previews will be generated at quality level 90.  As far as I can tell by the source code, this snippet is used to set the quality level:  protected function getJpegQuality() {

$quality = $this->config->getAppValue('preview', 'jpeg_quality', 90);

if...