JPEG involves a lossy compression mechanism using discrete cosine transform (DCT). JPEG is a joint standard of the International Telecommunications Union (ITU-T T.81) and the International Organization for Standardization (ISO 10918-1). JPG is a graphical file format for editing still images, it offers a symmetrical compression technique which is processor intensive and time consiming in both compression and decompression. The JPG file is a great format as it often manages to compress files to 1/10 of the size of the original file which is especially good for saving on bandwidth. The JPG format is often used in digital camera memory cards. The resultant 'lossy' file means that quality can never be recovered. JPG's are often used for web sites and email as they are generally smaller file sizes as they are lossy meaning that some image quality is lost when the JPG is compressed and saved. Ultimately this results in dramatically reduced file sizes. The background and foreground images are compressed using an algorithm named IW44 with the mask image compressed using JB2. DjVu files are typically seperated into three images - the background and foreground (around 100 dpi) and the mask image which is higher resolution (e.g. It promises smaller files sizes than standard PDF's and is therefore perceived to be superior to PDF's primarily due to it's higher compression ratio. There are a whole host of DjVu viewers, browser plugins, encoders and decoders available on both Mac and Windows.ĭjVu was initially developed by Yann LeCun, L�on Bottou, Patrick Haffner, and Paul G. It allows for scanned documents, photographs and very high resolution images to be distributed via the internet. DjVu was initially developed by AT&T and is used as an image compression technology that is an open sourced alternative to PDF.

How to convert djvu to pdf file