# iris_pipeline Documentation¶

The IRIS Data Reduction System is based on the stpipe package released by Space Telescope for the James Webb Space Telescope.

With stpipe we can define a pipeline using JSON and CFG (text based .INI style files) and custom analysis steps defined as classes in the current repository iris_pipeline

Then execute the pipeline from the command line using the strun executable or using directly the Python library.

The pipeline also dynamically interfaces to the CRDS the Calibration References Data System, to retrieve the best calibration datasets given the metadata in the headers of the input FITS files. The CRDS client can also load data from a local cache, so for now we do not have a actual CRDS server and we only rely on a local cache.

The CRDS is not under our control, the Thirty Meter Telescope will deliver a database system to replace the CRDS and we can adapt our code to that in the future.

## Reference/API¶

### iris_pipeline Package¶

#### Functions¶

 test(\*\*kwargs) Run the tests for the package.

#### Classes¶

 BackgroundStep([name, parent, config_file, …]) BackgroundStep: Subtract background exposures from target exposures. DQInitStep([name, parent, config_file, …]) Initialize the Data Quality extension from the mask reference file. FlatFieldStep([name, parent, config_file, …]) Flat-field a science image using a flatfield reference image. Image2Pipeline(*args, **kwargs) Image2Pipeline: Processes JWST imaging-mode slope data from Level-2a to Level-2b. SubtractImagesStep([name, parent, …]) SubtractImagesStep: Subtract two exposures from one another to accomplish background subtraction. UnsupportedPythonError