DjVuPhoto vs JPEG: Head to Head Comparison

This page uses the image on the right to compare JPEG and DjVuPhoto (the DjVu wavelet-based compression technology also known as IW44).

The advantages of DjVuPhoto over JPEG are made clear:

much higher quality than similarly sized JPEGs, or about half the size for a similar quality.
superior quality at high compression ratios (with graceful degradation, no "block" artifacts, and no color quantization artifacts).
very fast inital display with subsequent refinements (progressivity).
fast decoding, zooming, panning
low memory usage through on-the-fly decompression allows the display of very high-resolution images on modest PC configurations.

How the Images were Produced

The image was scanned from a slide with a slide scanner into a 3306x2450 pixel image, and then stored in JPEG with quasi-lossless quality (3:1 compression ratio). This original image can be obtained here (8,043,046 Bytes) [note: this image is Copyright Eric Cosatto 1999, use only for research purpose].

This image was then reduced by factors of 2,4,8, and 16, and compressed to JPEG at various quality settings using the Independent JPEG Group's program "cjpeg -q [percent-quality]" on Unix.

For each JPEG image (at each resolution and quality setting) a corresponding DjVu image of identical resolution was produced so as to approach the file size of the JPEG version as closely as possible. This was done using the program "c44 -size xxxxx+yyyyy+zzzzz [ppmfile] [djvufile]" on Unix.