EPS/AI/PDF のサムネイルが表示できます。 Xnview
これは、便利です。Xnview のFAQを読んでいたのですが、5c を実行してみてください。
5a.) Fine tuning: Resolution By default the raster images generated have 72dpi. If you want more detailed raster images set a higher resolution (DPI, dots per inch) in Tools > Options, Category "General > Read/Write", Tab "Read" > EPS/PS/AI/PDF".
5b.) Fine tuning: High quality display When viewing vector images, often they contain thin lines and/or text. It is strongly recommended to activate high quality display for both thumbnails and images. In options dialog, category "Browser > Thumbnails" activate the checkbox "Use high quality". And in category "View" activate the checkboxes for "High zoom quality (slower)". I recommend to activate "Reduce" and "Fit to Window/Desktop". Please note that when activate "Enlarge" zooming might become very slow for large images and large zoom factors (>400%).
5c.) Fine tuning: Thumbnails for Vector images. Converting vector files to image files needs quite some calculation. For this reason by default you will not see thumbnails for vector images. If you do not care too much about performance and want to see thumbnails for vector graphics, in Tools > Options, Category "Browser > File List" check the checkbox "Show as thumbnail" in the row labeled "AI, PS, PDF files".