{'fraction_non_alphanumeric': 0.011314186248912098, 'fraction_numerical': 0.02349869451697128, 'mean_word_length': 4.927835051546392, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
JPEG 2000 options for document image compression

The JPEG 2000 standard enables a variety of approaches suitable to document images. The JPM file format defined in Part 6 specifies a method for layered image compression of compound images and supports multiple compression types within a single page. This allows JBIG2, JPEG 2000 and other compressed data types to be applied to different regions of a single image. While the JPEG 2000 Part 1 codestream also offers a variety of options of possible interest with document images. Low bit per pixel representations of textual regions at moderate spatial resolutions can be appropriate for screen renditions of text regions. These may be coded as lossless, visually lossless or lossy data. Document images can also be palettized and compressed losslessly by the palettized image method of JPEG 2000. A bitonal representation of a document page may be compressed without any wavelet transform, using only the entropy coder portion of the JPEG 2000 specification, or it may be coded in a lossy manner. This study compares the visual quality and compressed sizes of some of these alternative approaches.