7. The method of claim 6 , wherein the electronic document is one of an electronic book, an electronic magazine, and an electronic newspaper.
6. A method for publishing an electronic document, the method comprising: receiving a plurality of high-resolution images to include in the electronic document; determining a maximum pixel width and pixel height resolution at which each high-resolution image of the plurality of high-resolution images will be displayed when the document is displayed on display screens having a particular resolution, wherein the maximum resolution needed to display at least a subset of the high-resolution images on the display screens having the particular resolution is lower than a resolution of the high-resolution images; associating a markup file with the high-resolution version of the electronic document, the markup language file comprising a plurality of annotations that each specifies the determined maximum resolution for a respective high-resolution image; and publishing the high-resolution version of the document and the associated markup file to a content distribution system without a low-resolution version of the document, wherein the content distribution system generates the low-resolution version of the electronic document by using the plurality of annotations to create a low-resolution version of each image having the determined maximum resolution for the image, the low-resolution version of the electronic document for distribution by the content distribution system to a plurality of client devices with display screens having the particular resolution and the high-resolution version of the electronic document for distribution by the content distribution system to a different plurality of client devices.