djvuxml1

Usage

Overview

The DjVuLibre XML Tools provide for editing the metadata, hyperlinks and hidden text associated with DjVu files. Unlike djvused(1) the DjVuLibre XML Tools rely on the XML technology and can take advantage of XML editors and verifiers.

Djvutoxml

Program djvutoxml creates a XML file outputxmlfile containing a reference to the original DjVu document inputdjvufile as well as tags describing the metadata, hyperlinks, and hidden text associated with the DjVu file.

The following options are supported:

--page pagenum

Select a page in a multi-page document. Without this option, djvutoxml outputs the XML corresponding to all pages of the document.

--with-text

Specifies the HIDDENTEXT element for each page should be included in the output. If specified without the --with-anno flag then the --without-anno is implied. If none of the --with-text, --without-text, --with-anno, or --without-anno, flags are specified, then the --with-text and --with-anno flags are implied.

--without-text

Specifies not to output the HIDDENTEXT element for each page. If specified without the --without-anno flag then the --with-anno flag is implied.

--with-anno

Specifies the area MAP element for each page should be included in the output. If specified without the --with-text flag then the --without-text flag is implied.

--without-anno

Specifies the area MAP element for each page should not be included in the output. If specified without the --without-text flag then the --with-text flag is implied.

Djvuxmlparser

Files produced by djvutoxml can then be modified using either a text editor or a XML editor. Program djvuxmlparser parses the XML file inputxmlfile in order to modify the metadata of the corresponding DjVu file.

-o djvufile

In principle the target DjVu file is the file referenced by the OBJECT element of the XML file. This option provides the means to override the filename specified in the OBJECT element.

Djvuxml document type definition

The document type definition file (DTD)

/usr/share/djvu/pubtext/DjVuXML-s.dtd

defines the input and output of the DjVu XML tools.

The DjVuXML-s DTD is a simplification of the HTML DTD:

http://www.w3c.org/TR/1998/REC-html40-19980424/sgml/dtd.html

with a few new attributes added specific to DjVu. Each of the specified pages of a DjVu document are represented as OBJECT elements within the BODY element of the XML file. Each OBJECT element may contain multiple PARAM elements to specify attributes like page name, resolution, and gamma factor. Each OBJECT element may also contain one HIDDENTTEXT element to specify the hidden text (usually generated with an OCR engine) within the DjVu page. In addition each OBJECT element may reference a single area MAP element which contains multiple AREA elements to represent all the hyperlink and highlight areas within the DjVu document.

PARAM Elements

Legal PARAM elements of a DjVu OBJECT include but are not limited to PAGE for specifying the page-name, GAMMA for specifying the gamma correction factor (normally 2.2), and DPI for specifying the page resolution.

HIDDENTEXT Elements

The HIDDENTEXT elements consists of nested elements of PAGECOLUMNS, REGION, PARAGRAPH, LINE, and WORD. The most deeply nested element specified, should specify the bounding coordinates of the element in top-down orientation. The body of the most deeply nested element should contain the text. Most DjVu documents use either LINE or WORD as the lowest level element, but any element is legal as the lowest level element. A white space is always added between WORD elements and a line feed is always added between LINE elements. Since languages such as Japanese do not use spaces between words, it is quite common for Asian OCR engines to use WORD as characters instead.

MAP Elements

The body of the MAP elements consist of AREA elements. In addition to the attributes listed in

http://www.w3.org/TR/1998/REC-html40-19980424/struct/objects.html#edef-AREA,

the attributes bordertype, bordercolor, border, and highlight have been added to specify border type, border color, border width, and highlight colors respectively. Legal values for each of these attributes are listed in the DjVuXML-s DTD. In addition, the shape oval has been added to the legal list of shapes. An oval uses a rectangular bounding box.

Credits

The DjVu XML tools and DTD were written by Bill C. Riemers <[email protected]> and Fred Crary.