The wwwopac.ashx offers functionality for efficiently retrieving and safely storing of images. Its high performance for retrieving and scaling of images for display in the Adlib Media Viewer or for thumbnail display on the brief display of a search result is accomplished by not resizing the images to be retrieved for every request, but by reducing or enlarging the image only when first requested, and then saving the result in a cache folder so that for a following identical request the next time a ready-made resized image can be retrieved. So the use of wwwopac.ashx for retrieving images is most useful if the images to which you link in your (museum) visual documentation records are pretty large files. For use in thumbnail displays, the image handler already scales those images on the server or retrieves earlier created thumbnails, which results in less data traffic on your network, it lightens the workload of the Adlib core software en also diminishes memory use of the work station enormously.
You can also use this functionality to directly and safely store images linked to in a visual documentation record, in an Adlib SQL or Adlib Oracle database, although you can store images in the file system as well.
To be able to work with images, you'll first have to configure the images server. Click here for
information about how to configure the images server in the adlibweb.xml file.
The two API functions for retrieving and respectively storing images, are
getcontent and writecontent.
Note that during the development phase of this functionality, there was talk of separate software named Image Handler which could have been used alongside wwwopac; however, the relevant functionality is now only available as part of wwwopac.ashx.