How To Use Image Grouping

In some instances, you may want to subdivide an image set into groups that share a common feature. For example, if you are performing illumination correction, we usually recommend that the illumination function be calculated on a per-plate basis, and hence each plate should be processed independently. Since running the same pipeline multiple times (one for each grop) would be time-consuming, CellProfiler is able to perform image grouping for this purpose. If the image subdivisions are distinguishable by some metadata (usually defined within the filename or folder location), grouping will enable you to process those images that have the metadata together.

To use grouping, you must define the relevant metadata for each image. This can be done using regular expressions in LoadImages or having them pre-defined in a .csv for use in LoadData.

To use image grouping in LoadImages, please note the following:

• Metadata tags must be specified for all images listed. You cannot use grouping unless an appropriate regular expression is defined for all the images listed in the module.
• Shared metadata tags must be specified with the same name for each image listed. For example, if you are grouping on the basis of a metadata tag "Plate" in one image channel, you must also specify the "Plate" metadata tag in the regular expression for the other channels that you want grouped together.

Please see LoadImages, LoadData, or Help > Using CellProfiler > How Data Is Handled > Using Metadata In CellProfiler for more details on obtaining, extracting, and using metadata tags from your images