DjVu technology is a highly sophisticated imaging language based on six advanced technological breakthroughs developed at AT&T Labs. Working together, they provide a reliable means of saving detailed scans at remarkably low file sizes.
Conventional image-viewing software decompresses images in their entirety before displaying them. This is impractical for high-resolution document images because the large file sizes involved typically exceed the capacity of most computers. DjVu technology, on the other hand, keeps the image in memory in a compact form and decodes only the area displayed on the screen in real time as the user views the image. As a result, the initial view of the page loads very quickly, and the visual quality progressively improves as more bits arrive. DjVu technology can achieve file size reduction ratios as great as 500:1 while preserving excellent image quality.