Gives the name of a file containing an image to be displayed inside a node. The image file must be in one of the recognized formats, typically JPEG, PNG, GIF, BMP, SVG or Postscript, and be able to be converted into the desired output format.

The file must contain the image size information. This is usually trivially true for the bitmap formats. For PostScript, the file must contain a line starting with %%BoundingBox: followed by four integers specifying the lower left x and y coordinates and the upper right x and y coordinates of the bounding box for the image, the coordinates being in points. An SVG image file must contain width and height attributes, typically as part of the svg element. The values for these should have the form of a floating point number, followed by optional units, e.g., width="76pt". Recognized units are in, px, pc, pt, cm and mm for inches, pixels, picas, points, centimeters and millimeters, respectively. The default unit is points.

Unlike with the shapefile attribute, the image is treated as node content rather than the entire node. In particular, an image can be contained in a node of any shape, not just a rectangle.