perClass Mira provides numerous ways how to extract and export information from a single or multiple images. The use case is to define a classifier, segment objects, or specify regions of interest and export user-defined features to an external file, either Excel .xlsx (or .xls) or XML. This data can then be used for custom analysis or further research.


Let us walk through a basic example using Feature extraction panel, in order to extract data, we need to specify:

  • Where the data is extracted from
  • What pixels are included in the extraction
  • What is being extracted



In the first example, we want to extract mean spectra from objects. Therefore, we select Mean spectrum from the Add representation combo box.



Note that you may select multiple representations.


Select one of more images in Images list and then, from the File menu select Export / Export region features to Excel. Note that you may also export the same data into XML, which is more convenient if you wish to programmatically post-process data analysis.



You will be asked for a name of a file to save to. By default, perClass Mira exports to XLSX format, because this format allows for more than 256 columns, which is useful if we're exporting a lot of features per object, for example mean spectra. If you prefer the legacy XLS format, you may choose it in the export dialog.


In the screenshot below we can see the structure of the exported data:



The objects of each selected image are described by rows.


For each object, we can see the scan name followed by an object name. When exporting object segmentation, the object name is automatically assigned in the segmentation procedure. When exporting content of user-defined regions, the region name is used, which can be user-assigned.  For each object, its bounding box and per-object decision are provided as well.


The Content present column shows whether there is content represented in this object/region and if so, how many pixels. When exporting objects, the content is always present, but when exporting regions, this may not be the case.


Finally, the section contains the exported data. In our case, these columns correspond to individual wavelengths of the mean spectra extracted for each object.