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.

As I look at this fictitious XML-formatted image, I tend to think that XML is not a good fit. Here’s why: Each pixel element contains text that is meaningless on its own. For example, what does <red>100</red> mean? Meaning – the image -- is spread over a large collection of elements. Perhaps, when meaning is spread widely and thinly, it is harder for applications to find meaning in XML than in binary?

Thoughts?

/Roger

<My-New-Image-Format>
    <Metadata>
        <make>Canon</make>
        <model>Canon EOS 60D</model>
        <exposure>1/100</exposure>
        <aperture>4.5</aperture>
        <focal-length>40.0 mm</focal-length>
        ...
    </Metadata>
    <Image>
        <Row>
            <Pixel>
                <Red>100</Red>
                <Green>0</Green>
                <Blue>0</Blue>
            </Pixel>
            <Pixel>
                <Red>100</Red>
                <Green>0</Green>
                <Blue>0</Blue>
            </Pixel>
            ...
        </Row>
        ...
    </Image>
</My-New-Image-Format>