LRViewer was developed to be a standalone viewer for Lightroom image previews that also allows you to extract previews as JPEG files. LRViewer makes no changes to the Lightroom catalog, which means that it can't create any previews that aren't already present.
Both the catalog (ending in "lrcat" or "lrdb") and the associated preview file (ending in "lrdata") must be present. You open just the catalog; LRViewer then opens the preview file automatically. No images have to be exported from Lightroom, since LRViewer accesses the catalog and previews directly. 

Using LRViewer:
· Select a picture to see its metadata in the panel at lower-left. Double-click a picture (or type `) to zoom it to fill the window, or to the largest preview size available. You can navigate between zoomed pictures with the arrow buttons at the top of the window or with the left and right arrow keys. You get back to the multi-image view with `, g, or Esc.
· From a large-size view, you can click the magnifying-glass cursor to zoom to 100%. Click again to return to the large-size view. Or, you can press the z key to zoom to 100% from any view, and press it again to return to the previous view
· The file name and rating are displayed below an image.
· You can export JPEGs with the File-Export JPEGs command. JPEGs are at the highest resolution available as a preview, and are at the same quality as the preview. LRViewer adds EXIF metadata and includes the XMP information as stored in the Lightroom catalog. The files are named as they are in the Lightroom database, with an extension of "jpg".
Color Management:
· Images shown on the screen are color managed if they use one of three profiles that frequently occur with Lightroom previews: sRGB, Adobe RGB (1998), and a custom Lightroom profile. Previews using any other profile are not color managed. (If you think you have one of these, please send an email using the link at left.)
· Exported JPEGs using Adobe RGB (1998) or the custom Lightroom profile have the profile embedded in them; sRGB JPEGs are merely tagged as being sRGB. JPEGs using other profiles are exported without a profile.
· LRViewer will not convert JPEGs to sRGB when exporting, so, as sRGB is rarely used in Lightroom, you may want to run exported JPEGs through another application that can convert them to sRGB before posting them on the web. (Although most web browsers aren't color-managed anyway, so it may not matter.)

Requirements:
· Lightroom