Re: [xml-dev] Is this a good use of XML: XML-formatted images?

[Michael Kay <mike@saxonica.com>]

On 29 Oct 2017, at 13:01, Costello, Roger L. <costello@mitre.org> wrote:

Hi Folks,

JPEG/JFIF, GIF, PNG, BMP are, as you know, binary data formats for images.

Why are there no XML-formatted images? Is XML not a good format for images? If it’s not, why not? I’ll speculate: perhaps the reason is simply that XML is too verbose. Is that the reason? Are there other reasons?

Below is a fictitious XML-formatted image. It has a metadata section with XML elements describing the image. After that is an image section containing the raw pixel (RGB) data.

MPEG-7 provides an XML format for metadata associated with multimedia content. But it doesn't use XML for the content itself. XML was never designed for binary data, and the bloat caused by fine-grained tagging of individual pixels would make the format unusable.

Michael Kay

Saxonica