2015-09-01 * Bug fix: The constraint for the confidence value of OCRed text was not inclusive for 0.0 and 1.0 - it is now inclusive. 2013-07-15 * The format of polygons stored in has been changed from elements to a 'points' attribute. A polygon is now represented by a space separated list of points (x and y are comma separated). A list requires at least two points (enforced by a regular expression constraint). Example: * All regions can now have nested sub-regions. Before this was limited to elements. * Frame regions have been removed from the schema. As a replacement can be used. * There are three new region types: , and for advertisements, chemical formulas and musical notations. * The child element of <TextEquiv> is now optional. * Text recognition confidence has been introduced as new attribute of <TextEquiv> * Language can now be specified on text line and word level, in addition to region level. Therefore <TextLine> elements have a new attribute 'primaryLanguage' and <Word> elements have a new attribute 'language'. Values set for child elements are interpreted to override values of parent elements. * The elements <Layer>, <UnorderedGroup> and <OrderedGroup> have a new attribute 'caption'. * Text lines can now have a <Baseline> child element. The baseline is a multi- segment line represented by a list of points ('points' attribute with the same format and constraints as polygon points). * The <Page> element has a new attribute 'type'. * The <Page> element has a new child element <AlternativeImage> (0..*) with attributes 'filename' and 'comments' (to be used for bi-level image etc.). * New attributes 'custom' and 'comments' for various elements. The former is intended for machine use (custom types for instance). The latter is intended for human use (context information, remarks etc.). * Extended constraint for 'type' attribute of <GraphicRegion> element. Added: 'decoration', 'barcode' and 'frame'. * Extended constraint for 'type' attribute of <TextRegion> element. Added: 'endnote' and 'other'. * Extended constraint for 'primaryLanguage' and 'secondaryLanguage' attributes of <TextRegion> element. Now conform to ISO standard. * Extended constraint for colour attributes. Added: 'other'. * Extended constraint for 'colourDepth' attribute. Added: 'other'. * The elements <TextRegion>, <TextLine>, <Word> and <Glyph> have a new child element <Textstyle> with attributes 'fontFamily', 'serif', 'monospace', 'fontSize', 'kerning', 'textColour', 'bgColour', 'reverseVideo', 'bold', 'italic', 'underlined', 'subscript', 'superscript', 'strikethrough', 'smallCaps', 'letterSpaced'. Any attributes of <TextRegion> that appear in this list have been removed (moved to <TextStyle>). Values set for child text objects are interpreted to override values of parent text objects. * New attribute 'production' for elements <TextRegion>, <TextLine>, <Word> and <Glyph>. Values set for child text objects are interpreted to override values of parent text objects. * New child element <Relations> for <Page> element to model relations between layout objects (e.g. drop-capital - paragraph, image - caption). Single relations are represented by <Relation> elements with attributes 'type', 'custom' and 'comments' as well as two <RegionRef> child elements. 2016-07-15 * New attributes for <Page> element (take priority over region-level values, if defined): - "primaryLangage" - “secondaryLanguage” - “primaryScript” - “secondaryScript” - “readingDirection” - “textLineOrder” (see below) * New attribute "externalRef" for <Metadata> element. Generic string that can point to an external document / resource * Changed constraints for "primaryScript" and "seconddaryScript" (<Page>, <TextRegion>, ...). Now based on ISO 15924 http://unicode.org/iso15924/iso15924-codes.html Requires migration from 'Chinese-Traditional' and 'Chinese-Simplified' to Han (Traditional variant) and Han (Simplified variant) * New attribute "textLineOrder" for <Page> and <TextRegion> elements. Represents the inner-block order of text lines (in addition to “readingDirection” which is the inner-text line order of words and characters) - String, optional - Constraints: top-to-bottom, bottom-to-top, left-to-right, right-to-left * New attribute "xHeight" for <TextStyle>. “The x-height or corpus size refers to the distance between the baseline and the mean line of lower-case letters in a typeface” - Integer, optional, Unit: pixel * New attribute "dataType" for <TextEquiv>. Repreents type of text content (observed or expected). - String, optional - Constraints: xsd:decimal, xsd:float, xsd:integer, xsd:boolean, xsd:date, xsd:time, xsd:dateTime,xsd:string,other * New attribute "dataTypeDetails" for <TextEquiv>. Refinement for “dataType”, e.g. a regular expression - String, optional * Changes for usage of <TextEquiv> element (sub-element of text region, text line, word and glyph): - Can now occur multiple times to reflect OCR / text variants - Additional “index” attribute can be used to order the variants (lowest index is used as main text content) - Additional “comments” attribute (explanations, e.g. if different OCRs are used or an annotated version of the text content is entered) - “conf” (OCR confidence) is attached to “TextEquiv” as before * Added attributes "primaryScript" and "secondaryScript" to <TextLine> and <Word> * New attribute "script" for <Glyph> element. Same constraints as "primaryScript" for <TextRegion> 2017-07-15 * Graphemes: New level below glyphs for compound characters. Includes new elements: - Graphemes (container) - Grapheme (with Coords) - GraphemeGroup (with child Grapheme and/or NonPrintingChar elements) - NonPrintingChar All with TextEquiv and following attributes: - ID - ligature - charType (character type - "base" or "combining") - custom - comments * User-defined attributes - New UserDefined element for Page, Metadata, regions, TextLine, Word, Glyph, and reading order groups - UserAttribute elements as child elements, with attributes: - name (String) - description (String) - type (String, one of xsd:string, xsd:integer, xsd:float, xsd:boolean) - value (String) * New Roles element for regions. Container for roles that nested regions take on in context of a parent region. - TableCellRole child element (e.g. for nested regions of a table region); attributes: - rowIndex, columnIndex - Position of the upper left corner of the cell in the table - rowSpan, colSpan - Height / width of the cell in the table * Extended text type constraint to include "list-label" for text regions that are list item labels (numbers or bullets) * New attributes for reading order groups: - type (string, one of: div, paragraph, list, list-item, figure, article, other) - custom (string) - comments (string) - regionRef (IDREF) - Optional link to a region. Can be used for parent regions that contain nested regions. The parent region can double as reading order group. Only nested regions should be allowed as group members. * New boolean attribute "continuation" for regions and reading order groups, indicating that an object is the continuation of another object in the previous column or page, for example * New string attributes "textColourRgb" and "bgColourRgb" for TextStyle elements. Alternative to named colours. Format is RGB encoded (red value) + (256 x green value) + (65536 x blue value). 2018-07-15 * Added MapRegion and CustomRegion * New confidence attribute ("conf") for Page, Coords (polygons), BaseLine, ReadingOrder, and AlternativeImage (value 0..1, confidence of algorithm that produced the object) * New "header" boolean attribute for TableCellRole (is the cell a column or row header?) * New "index" int attribute for TextLine (Position (order number) of the text line within its parent text region) * New "imageXResolution", "imageYResolution", "imageResolutionUnit" attributes for Page * New element "MetadataItem" for Metadata (for extended metadata) - "type" string attribute (optional, one of: author, imageProperties, processingStep, other) - "name" string attribute (optional) - "value" string attribute (required) * New "Grid" element for TableRegion (visible or virtual table grid / separators) - "GridPoints" sub element (one row in the points matrix) * Changed RelationType: Instead of 2 RegionRef sub elements there is now SourceRegionRef and TargetRegionRef. Added "id" attribute (required) * Added feature for semantic labels / tags for: MetadataItem, Page, regions, textlines, words, glyphs, reading order groups, Relation * - Labels element - groups labels from the same model * - Label element - the actual label * Added "AlternativeImage" as optional child element to Region, TextLine, Word, and Glyph. External image for the respective object. 2019-07-15 * Added TextStyle to Page element (default text style for whole page) * Added "orientation" float attribute to Page element (skew for the whole page) * Added underlineStyle attribute to TextStyleType (valid values: singleLine, doubleLine, other)