Thumbnails Mode

This page contains options that affects the appearance of thumbnails in file displays, as well as options that control how thumbnails are generated. The Appearance section contains the following settings:

• Size: Specify the size in pixel of thumbnail images (width x height). Thumbnails will be scaled down to fit within these boundaries, preserving their aspect ratio. The Make square button provides a quick way to set the width and height to the same values.
• Spacing: Specify the spacing between thumbnails (horizontal x vertical).
• Label: Specify the maximum number of lines of text that the thumbnail's label can display.
• Display labels: Display labels below thumbnails. If this option is on the filename will be displayed below each thumbnail.
• Display image and file size in label: If this option is on as well, Opus will display the size of the image (and the size of the file) in a smaller font below the thumbnail's label.
• Display borders: Draw borders around thumbnail images.
• Fill color: Specify the color used to fill the background of thumbnail images.

The other options on this page are:

• Cache thumbnails: This lets you control whether Opus caches thumbnails or not. Caching thumbnails takes up some disk space but can result in much quicker loading of thumbnails once they have been generated and cached. If caching is enabled, use the Adjust cache settings link to control the following cache options:
  • Use lossless compression: This makes Opus use a lossless compression method when storing cached thumbnail images - it will result in slightly higher quality thumbnails, but they'll take up more space and it can take longer to cache thumbnails the first time they are generated.
  • Cache thumbnails for images located on: This lets you specify which types of drives thumbnails will be cached for (e.g. you can turn caching off for fast local drives but leave it on for networks).
  • Maximum cache size: This lets you specify the maximum size of the thumbnail cache. The current size is displayed below, and you can use the Empty button to clear the cache completely.
• Display thumbnails for folders: This option enables the display of thumbnails for folders as well as for files.
  • Generate folder thumbnails via the shell: On Vista and Windows 7, this option makes Opus ask the system for thumbnails for folders. This results in the modern-looking 3D folder thumbnails that Explorer displays. Otherwise Opus uses its own flat 2D-style folder thumbnail.
  • Generate folder thumbnails from images inside folders: If this option is turned off, folder thumbnails will show a generic image representing a folder. With this option on, Opus will display miniature thumbnails for the first few files it finds within the folder, in the actual folder thumbnail itself.
• Load all thumbnails in a folder automatically: Normally Opus only generates thumbnails when it needs to display them, which means when you scroll through a large folder of images, there may be a small delay before thumbnails are loaded. With this option turned on, Opus will automatically begin loading thumbnails for all files in the folder when you navigate to a new location.
• Overlay rating: Opus will overlay the thumbnail image with stars to indicate its assigned rating (if you have assigned the file a rating, that is). Ratings are assigned using the metadata functions.
• Overlay relative dimension bars: Opus will draw small horizontal and vertical bar graphs over the thumbnail to represent the dimensions of that image file relative to the largest image in the current directory. This is particularly useful when you have multiple copies of the same image saved at different resolutions - their thumbnails will ordinarily all look the same, and the bar graphs let you tell at a glance which relative size each file is. This option can also be changed from a button or hotkey using the RELDIMENSIONOVERLAYS argument to the internal Set command.
• Overlay thumbnail with file type icon: Opus will display a small icon for the type of file in question in the bottom corner of the thumbnail image (e.g. a JPEG image will have the generic .jpg icon displayed in the corner of the thumbnail).
  • Hide file type icon if type not registered: With the above option on, the file type icon will not be shown if the file type is not registered. This mostly applies to image files that may have no file extension - Opus is still able to display thumbnails for them as it looks at the file contents to determine their type, but there would be no valid icon registered in the system that could be shown.
  • Hide file type icon if thumbnail is too small: If the generated thumbnail is too small, the file type icon will not be overlaid. This prevents the problem where the file type icon may actually be larger than the thumbnail and would obscure it completely.
• Use EXIF information to auto-rotate images: Most modern digital cameras contain an orientation sensor that records into the image the orientation of the camera when the picture was taken. If this option is turned on Opus will read the orientation information from the image and automatically rotate the displayed thumbnail so that it appears the right way up.
• Thumbnail threads: This determines how many background threads Opus will use to generate thumbnails. As thumbnail generation is mostly a CPU intensive task (decoding JPEG images, for example), increasing the number of threads can greatly speed up the generation of thumbnails. We don't recommend setting this to a number higher than the number of CPUs in your computer.