|  |  | 14.1 The elements of an Ipe XML file

## 14.1 The elements of an Ipe XML file

A file can optionally start with the `<?xml>` tag, which is simply ignored by Ipe.

The only element in the file must be `<ipe>`. The optional attribute `version` indicates the earliest Ipelib version that can interpret the document. This allows for extensions to the Ipe file format, but not for withdrawal of features. Ipe will refuse to load documents that require a version larger than its own. The optional attribute `creator` indicates the program that created the file, it is not interpreted by Ipe at all.

The `<ipe>` element contains, in this order, an optional `<info>` element, an optional `<preamble>` element, an optional series of `<bitmap>` and `<ipestyle>` elements, and a series of `<page>` elements.

The `<info>` element takes the optional attributes `title`, `author`, `subject`, `keywords`, `pagemode`, `bbox`, `created`, `modified`, and `numberpages`. The only value for `pagemode` currently understood by Ipe is `fullscreen`. If the value of `bbox` is `cropbox`, Ipe will create a `CropBox` attribute when saving to PDF. The value of `created` and `modified` should be a date in PDF format, that is a string like "D:20030127204100". If `numberpages` is `yes`, then Ipe will save PDF documents with visible page numbers on each page.

The contents of the `preamble` element is used as the LaTeX preamble when running LaTeX to process the text objects in the document. It should not contain a `\documentclass` command, but can contain `\usepackage` commands and macro definitions.

The contents of the `<ipestyle>` element is parsed as an Ipe style sheet, see below. Several style sheets form a stack or "cascade", with the last `<ipestyle>` element becoming the top-level style sheet. When symbolic names are looked up, the style sheets are checked from top to bottom. Ipe always appends the built-in standard style sheet at the bottom of the stack.

Each `<bitmap>` element defines a bitmap to be used by `<image>` objects. It takes the required attributes `id` (the value must be an integer that will define the bitmap throughout the Ipe document), `width` and `height` (integers, specifying the dimensions of the bitmap in pixels), `ColorSpace` (possible values are "DeviceGray", "DeviceRGB", and "DeviceCMYK"), `BitsPerComponent` (only 8 is currently allowed!), and `length` (indicating the number of bytes of image data). The optional attribute `Filter` can take one of the values "FlateDecode" or "DCTDecode" to indicate a compressed image (the latter is used for JPEG images). The `length` attribute can be omitted if there is no filter (Ipe can then deduce it from the other attributes).

The contents of the `<bitmap>` element is the image data in hexadecimal format. White space between bytes is ignored. If no filter is specified, pixels are stored row by row, with rows padded to a full byte boundary.

Note that images with color maps are not supported, and such support is not planned. (The Insert image ipelet does allow you to insert images with color maps, but they are stored as 24-bit images. Since the data is compressed, this does not seriously increase the image data size.)

|  |  | 14.1 The elements of an Ipe XML file