Accessing images through a xml object.

I realize that to go further toward an image processing application,  it becomes necessary to  store informations about processed images. Those informations could be stored in a xml object mirroring the tree directories on the hard disk.

Initially I hesitated between an ini file handled with configobj and a xml file. The facilities provided by Lxml convinced me to use that library.

The images are stored as follow: Project / Slide / Field / Fluorochromes/ images. A typical xml object representing a project would be:

<CytoGenet>

  <slide name="A">

    <field name="2" ROI="x0,y0,x1,y1">

      <fluorochrome name="F1">

        <image position="-1,-1" name="1.TIF" exposure="0.0"/>

      </fluorochrome>

      <fluorochrome name="F2">

        <image position="-1,-1" name="1.TIF" exposure="0.0"/>

      </fluorochrome>

    </field>

    <field name="1" ROI="x0,y0,x1,y1">

      <fluorochrome name="F1">

        <image position="-1,-1" name="1.TIF" exposure="0.0"/>

      </fluorochrome>

      <fluorochrome name="F2">

        <image position="-1,-1" name="1.TIF" exposure="0.0"/>

      </fluorochrome>

    </field>

  </slide>

  <slide name="B">

    <field name="1" ROI="x0,y0,x1,y1">

      <fluorochrome name="F1">

        <image position="-1,-1" name="1.TIF" exposure="0.0"/>

      </fluorochrome>

      <fluorochrome name="F2">

        <image position="-1,-1" name="1.TIF" exposure="0.0"/>

      </fluorochrome>

      <fluorochrome name="F3">

        <image position="-1,-1" name="1.TIF" exposure="0.0"/>

      </fluorochrome>

    </field>

  </slide>

</CytoGenet>

For example, we have here a project called Cytogenet, two slides: A or B. In the slide A, two microscopic fields where observed, a region of interest was recorded by its corners (x0,y0) and (x1,y1); the first field was observed with two fluorochromes F1 or F2, and one image was taken for each with a given exposure time.