The Zoomify Image Viewer can display tiles in JPEG or PNG format. PNG provides two benefits: support for transparency, and compression that is not 'lossy'*. In this example, the eyes of the Venetian mask example image have been cleared in an image editor prior to conversion with the Zoomify Converter. This allows the background image to show through.

The benefits of transparency are especially apparent when working with Overlays - multiple Zoomify Images in synchronized layers. The examples '32-Overlays' and '33-Overlays-Functions' demonstrate this effect and provide further information.

The Zoomify Converter is able to create PNG tiles using a simple output choice setting. See the Read Me First file in the Converter folder for details. If this feature is not present in the Converter included in your Zoomify product please contact Zoomify Support and the latest Converter will be provided!

*Note: the JPEG tiles used by Zoomify by default are compressed at a quality/compression setting of 80 and therefore provide significantly better compression than PNG tiles (on average, 10 to 1 rather than 2 to 1). This setting also ensures compression artifacts are not created such as 'jaggies' on diagonal lines. Should any specific image present any concern, the Converter provides control of the compression level. PNG tiles are therefore useful primarily for their support of transparency.