Book (tag)
From SnapMap
book is a tag that points to the book in which this photo appears. The value might identify just the book; it might identify the page it came from; it might even represent the position on the page of the image.
Contents |
ISBN
Here we use the ISBN and various ways of referring to pages and page areas to identify pictures.
This example refers to this photo of the Victoria Tower in the Palace of Westminster.
book=isbn://0670800589/p144
When there is more than one image on a page, we can refer to images such as this by number:
book=isbn://0670800589/p135/number:2
To avoid ambiguity over the natural ordering of the numbers, we can refer to the exact position on the scan of this by using resolution-independent percentages for width, height, xOffset and yOffset, thus:
book=isbn://0670800589/p135/width:27.0%;height:15.2%;xOffset:59.5%;yOffset:76.5%;rotation:0;
Open Library
For books without ISBNs, we can use IDs provided by the Open Library. We can refer to this as
book=openlibrary://OL2866891M/p135/number:2
BookML
BookML is a form of XML used for representing scanned books, notably the locations on the page of the pictures found in each scan. The most useful way of using BookML in SnapMap is simply to use the form of BookML where a single attribute gives the URL of the full file.
book=<bookml link="http://www.lorp.org/books/6146.bookml"/>
The file found at the given URL is expected to be a fully specified BookML file, recording the placements of all pictures in the book. This way, multiple photos in SnapMap, scanned from the same book, can all point to the same remote BookML file.
Pagination
In some examples above we used 'pnnn ' to indicate page 'nnn'. In some books, or in parts of books, there is no numbered pagination; this is very often the case for plates in older books. We therefore need a method of referring to pages, independent of any printed pagination.
We use 'sides' as the term that can refer to all pages from start to finish, including things not normally regarded as pages – such as the front cover. We start numbering at side 1, the front cover, and proceed sequentially to the back cover. All sides, even the inside front and rear endpapers, are counted in this scheme.
For example, Gavin Stamp’s 'The Changing Metropolis has pages numbered from 7 to 240. The half-title page has an implied page number 1. In terms of sides, we number the book from 1 to 248, where side 1 is the front cover, side 5 is page 1, side 11 is page 7 (the first numbered page), side 244 is page 240, and side 248 is the back cover. BookML links up the side number with page number, if it exists. Thus, these two book tags say the same thing about a picture on the page:
book=openlibrary://OL2866891M/p135/number:2 book=openlibrary://OL2866891M/139/number:2
