Since one can change the symbol size, e.g. for a preview thumbnail of a photo file on desktop, the preview looks very unsharp and unattractive. Is there a way to modify this? E.g. let the thumbnail generator spend more time on creating those preview icon symbols?
Thanks
The sharp icons are vector graphics. You would need to replace any fuzzy or low-resolution icons with SVGs to have them be sharp in bigger resolutions. You can customize any icon by right clicking and choosing 'Properties'. Then click on the current icon in the window to bring up a file browser to pick a replacement.
To make your own replacements, or to convert low-resolution current icons, you would need a graphics program like GIMP or Inkscape to make SVGs.
For photos, you would need to manually create an SVG of each one individually to have sharp thumbnails at bigger sizes.
Try resizing a few of the default icons on your desktop. Some are really sharp at any resolution, some are not. The sharp ones are vector graphics.