Computer implemented methods and data processing apparatus are described for displaying virtual slide images. Images of a plurality of slides are automatically displayed in a first region of a display device at a first magnification. The slides comprise all the slides including material from a same specimen. An image of at least one of the slides is displayed in a second region at a second magnification greater than the first magnification. At least the image displayed in the second region is changed responsive to receiving user input. Methods for automatically determining a slide layout pattern and methods for virtually melding glass slide images into a single image are also described.