We present a new image compression technique called \DjVu " that is speciically geared towards the compression of high-resolution, high-quality images of scanned documents in color. This enables fast transmission of document images over low-speed connections, while faithfully reproducing the visual aspect of the document, including color, fonts, pictures,… (More)
The Joint Bi-level Image Experts Group jbig, an international study group aaliated with isooiec and itu-t, is in the process of drafting a new standard for lossy and lossless compression of bi-level images. The new standard, informally referred to as jbig2, will support model-based coding for text and halftones to permit compression ratios up to three times… (More)
We give a detailed algorithm for fast text compression. Our algorithm, related to the PPM method, simpliies the modeling phase by eliminating the escape mechanism and speeds up coding by using a combination of quasi-arithmetic coding and Rice coding. We provide details of the use of quasi-arithmetic code tables, and analyze their compression performance.… (More)
We present the Z-Coder, a new adaptive data compression coder for coding binary data. The Z-Coder is derived from the Golomb run-length coder, and retains most of the speed and simplicity of the earlier coder. The Z-Coder can also be thought of as a multiplication-free approximate arithmetic coder, showing the close relationship between run-length coding… (More)
We show that high-resolution images can be encoded and decoded eeciently in parallel. We present an algorithm based on the hierarchical MLP method, used either with Huuman coding or with a new variant of arithmetic coding called quasi-arithmetic coding. The coding step can be parallelized, even though the codes for diierent pixels are of diierent lengths;… (More)
The state of the art in data compression is arithmetic coding, not the better-known Huffman method. Arithmetic coding gives greater compression, is faster for adaptive models, and clearly separates the model from the channel encoding.
Arithmetic coding, in conjunction with a suitable probabilistic model, can provide nearly optimal data compression. In this article we analyze the effect that the model and the particular implementation of arithmetic coding have on the code length obtained. Periodic scaling is often used in arithmetic coding implementations to reduce time and storage… (More)
— In this paper, we make a short foray through coding standards for still images and motion video. We first briefly discuss standards already in use, including: Group 3 and Group 4 for bilevel fax images; JPEG for still color images; and H.261, H.263, MPEG-1, and MPEG-2 for motion video. We then cover newly emerging standards such as JBIG1 and JBIG2 for… (More)