diff --git a/examples/notebooks b/examples/notebooks
index 5a9b127..d5ea844 160000
--- a/examples/notebooks
+++ b/examples/notebooks
@@ -1 +1 @@
-Subproject commit 5a9b127f06a39d326931728a0cf9850848fca205
+Subproject commit d5ea844b033e18d5fc3c82213c8bfde93465d47f
diff --git a/requirements.txt b/requirements.txt
index b12d8e4..59b101a 100755
--- a/requirements.txt
+++ b/requirements.txt
@@ -29,10 +29,10 @@ torch
 pytorch-lightning
 torchvision
 
-spatialdata
+spatialdata>=0.2.0
 napari-spatialdata
 pyqt5
 lxml_html_clean
 ashlar>=1.19.0
 networkx
-py-lmd @ git+https://github.com/MannLabs/py-lmd.git@refs/pull/11/head#egg=py-lmd
+py-lmd>=1.3.1
diff --git a/requirements_dev.txt b/requirements_dev.txt
index 088c9fb..9ff75f1 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -29,13 +29,13 @@ torch
 pytorch-lightning
 torchvision
 
-spatialdata
+spatialdata>=0.2.0
 napari-spatialdata
 pyqt5
 lxml_html_clean
 ashlar>=1.19.0
 networkx
-py-lmd @ git+https://github.com/MannLabs/py-lmd.git@refs/pull/11/head#egg=py-lmd
+py-lmd>=1.3.1
 
 #packages for building the documentation
 sphinx
diff --git a/src/scportrait/__init__.py b/src/scportrait/__init__.py
index 972a0f8..772f875 100644
--- a/src/scportrait/__init__.py
+++ b/src/scportrait/__init__.py
@@ -1,7 +1,18 @@
 """Top-level package for scPortrait"""
 
+# silence warnings
+import warnings
+
 from scportrait import io
 from scportrait import pipeline as pipeline
 from scportrait import plotting as pl
 from scportrait import processing as pp
 from scportrait import tools as tl
+
+# silence warning from spatialdata resulting in an older dask version see #139
+warnings.filterwarnings("ignore", message="ignoring keyword argument 'read_only'")
+
+# silence warning from cellpose resulting in missing parameter set in model call see #141
+warnings.filterwarnings(
+    "ignore", message=r"You are using `torch.load` with `weights_only=False`.*", category=FutureWarning
+)
diff --git a/src/scportrait/pipeline/_base.py b/src/scportrait/pipeline/_base.py
index ab35274..d241cdb 100644
--- a/src/scportrait/pipeline/_base.py
+++ b/src/scportrait/pipeline/_base.py
@@ -9,6 +9,8 @@
 import numpy as np
 import torch
 
+from scportrait.pipeline._utils.helper import read_config
+
 
 class Logable:
     """Create log entries.
@@ -92,6 +94,27 @@ def _clean_log_file(self):
         if os.path.exists(log_file_path):
             os.remove(log_file_path)
 
+    # def _clear_cache(self, vars_to_delete=None):
+    #     """Helper function to help clear memory usage. Mainly relevant for GPU based segmentations.
+
+    #     Args:
+    #         vars_to_delete (list): List of variable names (as strings) to delete.
+    #     """
+
+    #     # delete all specified variables
+    #     if vars_to_delete is not None:
+    #         for var_name in vars_to_delete:
+    #             if var_name in globals():
+    #                 del globals()[var_name]
+
+    #     if torch.cuda.is_available():
+    #         torch.cuda.empty_cache()
+
+    #     if torch.backends.mps.is_available():
+    #         torch.mps.empty_cache()
+
+    #     gc.collect()
+
     def _clear_cache(self, vars_to_delete=None):
         """Helper function to help clear memory usage. Mainly relevant for GPU based segmentations."""
 
@@ -137,7 +160,7 @@ class ProcessingStep(Logable):
     DEFAULT_SEGMENTATION_DIR_NAME = "segmentation"
     DEFAULT_TILES_FOLDER = "tiles"
 
-    DEFAULT_EXTRACTIN_DIR_NAME = "extraction"
+    DEFAULT_EXTRACTION_DIR_NAME = "extraction"
     DEFAULT_DATA_DIR = "data"
 
     DEFAULT_IMAGE_DTYPE = np.uint16
@@ -155,19 +178,41 @@ class ProcessingStep(Logable):
     DEFAULT_SELECTION_DIR_NAME = "selection"
 
     def __init__(
-        self, config, directory, project_location, debug=False, overwrite=False, project=None, filehandler=None
+        self,
+        config,
+        directory=None,
+        project_location=None,
+        debug=False,
+        overwrite=False,
+        project=None,
+        filehandler=None,
+        from_project: bool = False,
     ):
         super().__init__(directory=directory)
 
         self.debug = debug
         self.overwrite = overwrite
-        self.project_location = project_location
-        self.config = config
+        if from_project:
+            self.project_run = True
+            self.project_location = project_location
+            self.project = project
+            self.filehandler = filehandler
+        else:
+            self.project_run = False
+            self.project_location = None
+            self.project = None
+            self.filehandler = None
+
+        if isinstance(config, str):
+            config = read_config(config)
+            if self.__class__.__name__ in config.keys():
+                self.config = config[self.__class__.__name__]
+            else:
+                self.config = config
+        else:
+            self.config = config
         self.overwrite = overwrite
 
-        self.project = project
-        self.filehandler = filehandler
-
         self.get_context()
 
         self.deep_debug = False
diff --git a/src/scportrait/pipeline/_utils/helper.py b/src/scportrait/pipeline/_utils/helper.py
index 9b11fa2..e930104 100644
--- a/src/scportrait/pipeline/_utils/helper.py
+++ b/src/scportrait/pipeline/_utils/helper.py
@@ -1,9 +1,20 @@
 from typing import TypeVar
 
+import yaml
+
 T = TypeVar("T")
 
 
-def flatten(nested_list: list[list[T]]) -> list[T]:
+def read_config(config_path: str) -> dict:
+    with open(config_path) as stream:
+        try:
+            config = yaml.safe_load(stream)
+        except yaml.YAMLError as exc:
+            print(exc)
+    return config
+
+
+def flatten(nested_list: list[list[T]]) -> list[T | tuple[T]]:
     """Flatten a list of lists into a single list.
 
     Args:
diff --git a/src/scportrait/pipeline/_utils/sdata_io.py b/src/scportrait/pipeline/_utils/sdata_io.py
index 47017a1..89c480e 100644
--- a/src/scportrait/pipeline/_utils/sdata_io.py
+++ b/src/scportrait/pipeline/_utils/sdata_io.py
@@ -71,10 +71,12 @@ def _read_sdata(self) -> SpatialData:
             _sdata = SpatialData()
             _sdata.write(self.sdata_path, overwrite=True)
 
+        allowed_labels = ["seg_all_nucleus", "seg_all_cytosol"]
         for key in _sdata.labels:
-            segmentation_object = _sdata.labels[key]
-            if not hasattr(segmentation_object.attrs, "cell_ids"):
-                segmentation_object = spLabels2DModel().convert(segmentation_object, classes=None)
+            if key in allowed_labels:
+                segmentation_object = _sdata.labels[key]
+                if not hasattr(segmentation_object.attrs, "cell_ids"):
+                    segmentation_object = spLabels2DModel().convert(segmentation_object, classes=None)
 
         return _sdata
 
diff --git a/src/scportrait/pipeline/extraction.py b/src/scportrait/pipeline/extraction.py
index ff51dfd..20bfbb7 100644
--- a/src/scportrait/pipeline/extraction.py
+++ b/src/scportrait/pipeline/extraction.py
@@ -57,7 +57,13 @@ def __init__(self, *args, **kwargs):
             self.overwrite_run_path = self.overwrite
 
     def _get_compression_type(self):
-        self.compression_type = "lzf" if self.compression else None
+        if (self.compression is True) or (self.compression == "lzf"):
+            self.compression_type = "lzf"
+        elif self.compression == "gzip":
+            self.compression_type = "gzip"
+        else:
+            self.compression_type = None
+        self.log(f"Compression algorithm: {self.compression_type}")
         return self.compression_type
 
     def _check_config(self):
@@ -261,24 +267,55 @@ def _get_segmentation_info(self):
                 f"Found no segmentation masks with key {self.segmentation_key}. Cannot proceed with extraction."
             )
 
-        # get relevant segmentation masks to perform extraction on
-        nucleus_key = f"{self.segmentation_key}_nucleus"
+        # intialize default values to track what should be extracted
+        self.nucleus_key = None
+        self.cytosol_key = None
+        self.extract_nucleus_mask = False
+        self.extract_cytosol_mask = False
 
-        if nucleus_key in relevant_masks:
-            self.extract_nucleus_mask = True
-            self.nucleus_key = nucleus_key
-        else:
-            self.extract_nucleus_mask = False
-            self.nucleus_key = None
+        if "segmentation_mask" in self.config:
+            allowed_mask_values = ["nucleus", "cytosol"]
+            allowed_mask_values = [f"{self.segmentation_key}_{x}" for x in allowed_mask_values]
+
+            if isinstance(self.config["segmentation_mask"], str):
+                assert self.config["segmentation_mask"] in allowed_mask_values
 
-        cytosol_key = f"{self.segmentation_key}_cytosol"
+                if "nucleus" in self.config["segmentation_mask"]:
+                    self.nucleus_key = self.config["segmentation_mask"]
+                    self.extract_nucleus_mask = True
+
+                elif "cytosol" in self.config["segmentation_mask"]:
+                    self.cytosol_key = self.config["segmentation_mask"]
+                    self.extract_cytosol_mask = True
+                else:
+                    raise ValueError(
+                        f"Segmentation mask {self.config['segmentation_mask']} is not a valid mask to extract from."
+                    )
+
+            elif isinstance(self.config["segmentation_mask"], list):
+                assert all(x in allowed_mask_values for x in self.config["segmentation_mask"])
+
+                for x in self.config["segmentation_mask"]:
+                    if "nucleus" in x:
+                        self.nucleus_key = x
+                        self.extract_nucleus_mask = True
+                    if "cytosol" in x:
+                        self.cytosol_key = x
+                        self.extract_cytosol_mask = True
 
-        if cytosol_key in relevant_masks:
-            self.extract_cytosol_mask = True
-            self.cytosol_key = cytosol_key
         else:
-            self.extract_cytosol_mask = False
-            self.cytosol_key = None
+            # get relevant segmentation masks to perform extraction on
+            nucleus_key = f"{self.segmentation_key}_nucleus"
+
+            if nucleus_key in relevant_masks:
+                self.extract_nucleus_mask = True
+                self.nucleus_key = nucleus_key
+
+            cytosol_key = f"{self.segmentation_key}_cytosol"
+
+            if cytosol_key in relevant_masks:
+                self.extract_cytosol_mask = True
+                self.cytosol_key = cytosol_key
 
         self.n_masks = np.sum([self.extract_nucleus_mask, self.extract_cytosol_mask])
         self.masks = [x for x in [self.nucleus_key, self.cytosol_key] if x is not None]
@@ -415,7 +452,7 @@ def _save_removed_classes(self, classes):
         # define path where classes should be saved
         filtered_path = os.path.join(
             self.project_location,
-            self.DEFAULT_SEGMENTATION_DIR_NAME,
+            self.DEFAULT_EXTRACTION_DIR_NAME,
             self.DEFAULT_REMOVED_CLASSES_FILE,
         )
 
@@ -636,7 +673,7 @@ def _transfer_tempmmap_to_hdf5(self):
                     axs[i].imshow(img, vmin=0, vmax=1)
                     axs[i].axis("off")
                 fig.tight_layout()
-                fig.show()
+                plt.show(fig)
 
         self.log("Transferring extracted single cells to .hdf5")
 
@@ -651,7 +688,8 @@ def _transfer_tempmmap_to_hdf5(self):
             )  # increase to 64 bit otherwise information may become truncated
 
             self.log("single-cell index created.")
-            self._clear_cache(vars_to_delete=[cell_ids])
+            del cell_ids
+            # self._clear_cache(vars_to_delete=[cell_ids]) # this is not working as expected so we will just delete the variable directly
 
             _, c, x, y = _tmp_single_cell_data.shape
             single_cell_data = hf.create_dataset(
@@ -668,7 +706,8 @@ def _transfer_tempmmap_to_hdf5(self):
                 single_cell_data[ix] = _tmp_single_cell_data[i]
 
             self.log("single-cell data created")
-            self._clear_cache(vars_to_delete=[single_cell_data])
+            del single_cell_data
+            # self._clear_cache(vars_to_delete=[single_cell_data]) # this is not working as expected so we will just delete the variable directly
 
             # also transfer labelled index to HDF5
             index_labelled = _tmp_single_cell_index[keep_index]
@@ -684,7 +723,8 @@ def _transfer_tempmmap_to_hdf5(self):
             hf.create_dataset("single_cell_index_labelled", data=index_labelled, chunks=None, dtype=dt)
 
             self.log("single-cell index labelled created.")
-            self._clear_cache(vars_to_delete=[index_labelled])
+            del index_labelled
+            # self._clear_cache(vars_to_delete=[index_labelled]) # this is not working as expected so we will just delete the variable directly
 
             hf.create_dataset(
                 "channel_information",
@@ -692,10 +732,18 @@ def _transfer_tempmmap_to_hdf5(self):
                 dtype=h5py.special_dtype(vlen=str),
             )
 
+            hf.create_dataset(
+                "n_masks",
+                data=self.n_masks,
+                dtype=int,
+            )
+
             self.log("channel information created.")
 
         # cleanup memory
-        self._clear_cache(vars_to_delete=[_tmp_single_cell_index, index_labelled])
+        del _tmp_single_cell_index
+        # self._clear_cache(vars_to_delete=[_tmp_single_cell_index]) # this is not working as expected so we will just delete the variable directly
+
         os.remove(self._tmp_single_cell_data_path)
         os.remove(self._tmp_single_cell_index_path)
 
@@ -808,7 +856,6 @@ def process(self, partial=False, n_cells=None, seed=42):
                 # directory where intermediate results should be saved
                 cache: "/mnt/temp/cache"
         """
-
         total_time_start = timeit.default_timer()
 
         start_setup = timeit.default_timer()
@@ -871,13 +918,13 @@ def process(self, partial=False, n_cells=None, seed=42):
 
             self.log("Running in single threaded mode.")
             results = []
-            for arg in tqdm(args):
+            for arg in tqdm(args, total=len(args), desc="Processing cell batches"):
                 x = f(arg)
                 results.append(x)
         else:
             # set up function for multi-threaded processing
             f = func_partial(self._extract_classes_multi, self.px_centers)
-            batched_args = self._generate_batched_args(args)
+            args = self._generate_batched_args(args)
 
             self.log(f"Running in multiprocessing mode with {self.threads} threads.")
             with mp.get_context("fork").Pool(
@@ -885,17 +932,19 @@ def process(self, partial=False, n_cells=None, seed=42):
             ) as pool:  # both spawn and fork work but fork is faster so forcing fork here
                 results = list(
                     tqdm(
-                        pool.imap(f, batched_args),
-                        total=len(batched_args),
+                        pool.imap(f, args),
+                        total=len(args),
                         desc="Processing cell batches",
                     )
                 )
                 pool.close()
                 pool.join()
-                print("multiprocessing done.")
 
             self.save_index_to_remove = flatten(results)
 
+        # cleanup memory and remove any no longer required variables
+        del results, args
+        # self._clear_cache(vars_to_delete=["results", "args"]) # this is not working as expected at the moment so need to manually delete the variables
         stop_extraction = timeit.default_timer()
 
         # calculate duration
@@ -912,7 +961,6 @@ def process(self, partial=False, n_cells=None, seed=42):
             self.DEFAULT_LOG_NAME = "processing.log"  # change log name back to default
 
         self._post_extraction_cleanup()
-
         total_time_stop = timeit.default_timer()
         total_time = total_time_stop - total_time_start
 
diff --git a/src/scportrait/pipeline/featurization.py b/src/scportrait/pipeline/featurization.py
index 316b6aa..9a0cbee 100644
--- a/src/scportrait/pipeline/featurization.py
+++ b/src/scportrait/pipeline/featurization.py
@@ -5,6 +5,7 @@
 from contextlib import redirect_stdout
 from functools import partial as func_partial
 
+import h5py
 import numpy as np
 import pandas as pd
 import pytorch_lightning as pl
@@ -36,6 +37,7 @@ def __init__(self, *args, **kwargs):
         self.model = None
         self.transforms = None
         self.expected_imagesize = None
+        self.data_type = None
 
         self._setup_channel_selection()
 
@@ -59,7 +61,10 @@ def _setup_output(self):
         if not os.path.isdir(self.directory):
             os.makedirs(self.directory)
 
-        self.run_path = os.path.join(self.directory, f"{self.data_type}_{self.label}")
+        if self.data_type is None:
+            self.run_path = os.path.join(self.directory, self.label)
+        else:
+            self.run_path = os.path.join(self.directory, f"{self.data_type}_{self.label}")
 
         if not os.path.isdir(self.run_path):
             os.makedirs(self.run_path)
@@ -104,6 +109,25 @@ def _detect_automatic_inference_device(self):
 
         return inference_device
 
+    def _get_nmasks(self):
+        if "n_masks" not in self.__dict__.keys():
+            if isinstance(self.extraction_file, str):
+                with h5py.File(self.extraction_file, "r") as f:
+                    self.n_masks = f["n_masks"][()].item()
+            if isinstance(self.extraction_file, list):
+                n_masks = []
+                for file in self.extraction_file:
+                    with h5py.File(file, "r") as f:
+                        n_masks.append(f["n_masks"][()].item())
+                assert (
+                    x == n_masks[0] for x in n_masks
+                ), "number of masks are not consistent over all passed HDF5 files."
+                self.n_masks = n_masks[0]
+            try:
+                self.n_masks = h5py.File(self.extraction_file, "r")["n_masks"][()].item()
+            except Exception as e:
+                raise ValueError(f"Could not extract number of masks from HDF5 file. Error: {e}") from e
+
     def _setup_inference_device(self):
         """
         Configure the featurization run to use the specified inference device.
@@ -166,10 +190,13 @@ def _setup_inference_device(self):
             self.inference_device = self._detect_automatic_inference_device()
             self.log(f"Automatically configured inferece device to {self.inference_device}")
 
-    def _general_setup(self):
+    def _general_setup(self, extraction_dir: str | list[str], return_results: bool = False):
         """Helper function to execute all setup functions that are common to all featurization steps."""
 
-        self._setup_output()
+        self.extraction_file = extraction_dir
+        if not return_results:
+            self._setup_output()
+        self._get_nmasks()
         self._setup_log_transform()
         self._setup_inference_device()
 
@@ -391,7 +418,8 @@ def configure_transforms(self, selected_transforms: list):
 
     def generate_dataloader(
         self,
-        extraction_dir: str,
+        extraction_dir: str | list[str],
+        labels: int | list[int] = 0,
         selected_transforms: transforms.Compose = transforms.Compose([]),
         size: int = 0,
         seed: int | None = 42,
@@ -428,11 +456,20 @@ def generate_dataloader(
             self.log(f"Expected image size is set to {self.expected_imagesize}. Resizing images to this size.")
             t = transforms.Compose([t, transforms.Resize(self.expected_imagesize)])
 
+        if isinstance(extraction_dir, list):
+            assert isinstance(labels, list), "If multiple directories are provided, multiple labels must be provided."
+            paths = extraction_dir
+            labels = labels
+        elif isinstance(extraction_dir, str):
+            assert isinstance(labels, int), "If only one directory is provided, only one label must be provided."
+            paths = [extraction_dir]
+            labels = [labels]
+
         f = io.StringIO()
         with redirect_stdout(f):
             dataset = dataset_class(
-                dir_list=[extraction_dir],
-                dir_labels=[0],
+                dir_list=paths,
+                dir_labels=labels,
                 transform=t,
                 return_id=True,
                 select_channel=self.channel_selection,
@@ -780,8 +817,8 @@ def _setup_transforms(self) -> None:
 
         return
 
-    def _setup(self):
-        self._general_setup()
+    def _setup(self, extraction_dir: str, return_results: bool):
+        self._general_setup(extraction_dir=extraction_dir, return_results=return_results)
         self._get_model_specs()
         self._get_network_dir()
 
@@ -799,7 +836,7 @@ def _setup(self):
         self._setup_encoders()
         self._setup_transforms()
 
-    def process(self, extraction_dir: str, size: int = 0):
+    def process(self, extraction_dir: str, labels: int | list[int] = 0, size: int = 0, return_results: bool = False):
         """
         Perform classification on the provided HDF5 dataset.
 
@@ -876,31 +913,39 @@ class based on the previous single-cell extraction. Therefore, only the second a
         self.log("Started MLClusterClassifier classification.")
 
         # perform setup
-        self._setup()
+        self._setup(extraction_dir=extraction_dir, return_results=return_results)
 
         self.dataloader = self.generate_dataloader(
             extraction_dir,
+            labels=labels,
             selected_transforms=self.transforms,
             size=size,
             dataset_class=self.DEFAULT_DATA_LOADER,
         )
 
         # perform inference
+        all_results = []
         for model in self.models:
             self.log(f"Starting inference for model encoder {model.__name__}")
             results = self.inference(self.dataloader, model)
 
-            output_name = f"inference_{model.__name__}"
-            path = os.path.join(self.run_path, f"{output_name}.csv")
+            if not return_results:
+                output_name = f"inference_{model.__name__}"
+                path = os.path.join(self.run_path, f"{output_name}.csv")
 
-            self._write_results_csv(results, path)
-            self._write_results_sdata(results, label=f"{self.label}_{model.__name__}")
-
-        self.log(f"Results saved to file: {path}")
+                self._write_results_csv(results, path)
+                self._write_results_sdata(results, label=f"{self.label}_{model.__name__}")
+            else:
+                all_results.append(results)
 
-        # perform post processing cleanup
-        if not self.deep_debug:
-            self._post_processing_cleanup()
+        if return_results:
+            self._clear_cache()
+            return all_results
+        else:
+            self.log(f"Results saved to file: {path}")
+            # perform post processing cleanup
+            if not self.deep_debug:
+                self._post_processing_cleanup()
 
 
 class EnsembleClassifier(_FeaturizationBase):
@@ -952,8 +997,8 @@ def _load_models(self):
         memory_usage = self._get_gpu_memory_usage()
         self.log(f"GPU memory usage after loading models: {memory_usage}")
 
-    def _setup(self):
-        self._general_setup()
+    def _setup(self, extraction_dir: str, return_results: bool):
+        self._general_setup(extraction_dir=extraction_dir, return_results=return_results)
         self._get_model_specs()
         self._setup_transforms()
 
@@ -965,7 +1010,7 @@ def _setup(self):
 
         self._load_models()
 
-    def process(self, extraction_dir, size=0):
+    def process(self, extraction_dir: str, labels: int | list[int] = 0, size: int = 0, return_results: bool = False):
         """
         Function called to perform classification on the provided HDF5 dataset.
 
@@ -1020,29 +1065,39 @@ class based on the previous single-cell extraction. Therefore, no parameters nee
 
         self.log("Starting Ensemble Classification")
 
-        self._setup()
+        self._setup(extraction_dir=extraction_dir, return_results=return_results)
 
         self.dataloader = self.generate_dataloader(
             extraction_dir,
+            labels=labels,
             selected_transforms=self.transforms,
             size=size,
             dataset_class=self.DEFAULT_DATA_LOADER,
         )
 
         # perform inference
+        all_results = {}
         for model_name, model in zip(self.model_names, self.model, strict=False):
             self.log(f"Starting inference for model {model_name}")
             results = self.inference(self.dataloader, model)
 
             output_name = f"ensemble_inference_{model_name}"
-            path = os.path.join(self.run_path, f"{output_name}.csv")
 
-            self._write_results_csv(results, path)
-            self._write_results_sdata(results, label=model_name)
+            if not return_results:
+                path = os.path.join(self.run_path, f"{output_name}.csv")
 
-        # perform post processing cleanup
-        if not self.deep_debug:
-            self._post_processing_cleanup()
+                self._write_results_csv(results, path)
+                self._write_results_sdata(results, label=model_name)
+            else:
+                all_results[model_name] = results
+
+        if return_results:
+            self._clear_cache()
+            return all_results
+        else:
+            # perform post processing cleanup
+            if not self.deep_debug:
+                self._post_processing_cleanup()
 
 
 ####### CellFeaturization based on Classic Featurecalculation #######
@@ -1079,10 +1134,24 @@ def _setup_transforms(self):
         return
 
     def _get_channel_specs(self):
-        if "channel_names" in self.project.__dict__.keys():
-            self.channel_names = self.project.channel_names
+        if self.project is None:
+            if isinstance(self.extraction_file, str):
+                with h5py.File(self.extraction_file, "r") as f:
+                    self.channel_names = list(f["channel_information"][:].astype(str))
+            if isinstance(self.extraction_file, list):
+                channel_names = []
+                for file in self.extraction_file:
+                    with h5py.File(file, "r") as f:
+                        channel_names.append(list(f["channel_information"][:].astype(str)))
+                assert (
+                    x == channel_names[0] for x in channel_names
+                ), "Channel names are not consistent over all passed HDF5 files."
+                self.channel_names = channel_names[0]
         else:
-            self.channel_names = self.project.input_image.c.values
+            if "channel_names" in self.project.__dict__.keys():
+                self.channel_names = self.project.channel_names
+            else:
+                self.channel_names = self.project.input_image.c.values
 
     def _generate_column_names(
         self,
@@ -1294,12 +1363,14 @@ def __init__(self, *args, **kwargs):
 
         self.channel_selection = None  # ensure that all images are passed to the function
 
-    def _setup(self):
-        self._general_setup()
+    def _setup(self, extraction_dir: str | list[str], return_results: bool):
+        self._general_setup(extraction_dir=extraction_dir, return_results=return_results)
         self._setup_transforms()
         self._get_channel_specs()
 
-    def process(self, extraction_dir, size=0):
+    def process(
+        self, extraction_dir: str | list[str], labels: int | list[int] = 0, size: int = 0, return_results: bool = False
+    ):
         """
         Perform featurization on the provided HDF5 dataset.
 
@@ -1354,10 +1425,11 @@ def process(self, extraction_dir, size=0):
         self.log("Started CellFeaturization of all available channels.")
 
         # perform setup
-        self._setup()
+        self._setup(extraction_dir=extraction_dir, return_results=return_results)
 
         self.dataloader = self.generate_dataloader(
             extraction_dir,
+            labels=labels,
             selected_transforms=self.transforms,
             size=size,
             dataset_class=self.DEFAULT_DATA_LOADER,
@@ -1384,15 +1456,19 @@ def process(self, extraction_dir, size=0):
             column_names=self.column_names,
         )
 
-        output_name = "calculated_image_features"
-        path = os.path.join(self.run_path, f"{output_name}.csv")
+        if return_results:
+            self._clear_cache()
+            return results
+        else:
+            output_name = "calculated_image_features"
+            path = os.path.join(self.run_path, f"{output_name}.csv")
 
-        self._write_results_csv(results, path)
-        self._write_results_sdata(results)
+            self._write_results_csv(results, path)
+            self._write_results_sdata(results)
 
-        # perform post processing cleanup
-        if not self.deep_debug:
-            self._post_processing_cleanup()
+            # perform post processing cleanup
+            if not self.deep_debug:
+                self._post_processing_cleanup()
 
 
 class CellFeaturizer_single_channel(_cellFeaturizerBase):
@@ -1408,20 +1484,23 @@ def _setup_channel_selection(self):
             self.channel_selection = [0, self.channel_selection]
         return
 
-    def _setup(self):
-        self._general_setup()
+    def _setup(self, extraction_dir: str | list[str], return_results: bool):
+        self._general_setup(extraction_dir=extraction_dir, return_results=return_results)
         self._setup_channel_selection()
         self._setup_transforms()
         self._get_channel_specs()
 
-    def process(self, extraction_dir, size=0):
+    def process(
+        self, extraction_dir: str | list[str], labels: int | list[int] = 0, size=0, return_results: bool = False
+    ):
         self.log(f"Started CellFeaturization of selected channel {self.channel_selection}.")
 
         # perform setup
-        self._setup()
+        self._setup(extraction_dir=extraction_dir, return_results=return_results)
 
         self.dataloader = self.generate_dataloader(
             extraction_dir,
+            labels=labels,
             selected_transforms=self.transforms,
             size=size,
             dataset_class=self.DEFAULT_DATA_LOADER,
diff --git a/src/scportrait/pipeline/project.py b/src/scportrait/pipeline/project.py
index ae20d64..c219ee3 100644
--- a/src/scportrait/pipeline/project.py
+++ b/src/scportrait/pipeline/project.py
@@ -23,7 +23,6 @@
 import numpy as np
 import psutil
 import xarray
-import yaml
 from alphabase.io import tempmmap
 from napari_spatialdata import Interactive
 from ome_zarr.io import parse_url
@@ -33,6 +32,7 @@
 
 from scportrait.io import daskmmap
 from scportrait.pipeline._base import Logable
+from scportrait.pipeline._utils.helper import read_config
 from scportrait.pipeline._utils.sdata_io import sdata_filehandler
 from scportrait.pipeline._utils.spatialdata_helper import (
     calculate_centroids,
@@ -94,7 +94,7 @@ class Project(Logable):
     def __init__(
         self,
         project_location: str,
-        config_path: str,
+        config_path: str = None,
         segmentation_f=None,
         extraction_f=None,
         featurization_f=None,
@@ -185,11 +185,7 @@ def _load_config_from_file(self, file_path):
         if not os.path.isfile(file_path):
             raise ValueError(f"Your config path {file_path} is invalid.")
 
-        with open(file_path) as stream:
-            try:
-                self.config = yaml.safe_load(stream)
-            except yaml.YAMLError as exc:
-                print(exc)
+        self.config = read_config(file_path)
 
     def _get_config_file(self, config_path: str | None = None) -> None:
         """Load the config file for the project. If no config file is passed the default config file in the project directory is loaded.
@@ -257,6 +253,7 @@ def _setup_segmentation_f(self, segmentation_f):
                 overwrite=self.overwrite,
                 project=None,
                 filehandler=self.filehandler,
+                from_project=True,
             )
 
     def _setup_extraction_f(self, extraction_f):
@@ -285,6 +282,7 @@ def _setup_extraction_f(self, extraction_f):
                 overwrite=self.overwrite,
                 project=self,
                 filehandler=self.filehandler,
+                from_project=True,
             )
 
     def _setup_featurization_f(self, featurization_f):
@@ -309,9 +307,10 @@ def _setup_featurization_f(self, featurization_f):
                 self.featurization_directory,
                 project_location=self.project_location,
                 debug=self.debug,
-                overwrite=self.overwrite,
+                overwrite=False,  # this needs to be set to false as the featurization step should not remove previously created features
                 project=self,
                 filehandler=self.filehandler,
+                from_project=True,
             )
 
     def _setup_selection(self, selection_f):
@@ -339,6 +338,7 @@ def _setup_selection(self, selection_f):
                 overwrite=self.overwrite,
                 project=self,
                 filehandler=self.filehandler,
+                from_project=True,
             )
 
     def update_featurization_f(self, featurization_f):
@@ -888,9 +888,10 @@ def load_input_from_sdata(
         # ensure that the provided nucleus and cytosol segmentations fullfill the scPortrait requirements
         # requirements are:
         # 1. The nucleus segmentation mask and the cytosol segmentation mask must contain the same ids
-        assert (
-            self.sdata[self.nuc_seg_name].attrs["cell_ids"] == self.sdata[self.cyto_seg_name].attrs["cell_ids"]
-        ), "The nucleus segmentation mask and the cytosol segmentation mask must contain the same ids."
+        if self.nuc_seg_status in self.sdata.keys() and self.cyto_seg_status in self.sdata.keys():
+            assert (
+                self.sdata[self.nuc_seg_name].attrs["cell_ids"] == self.sdata[self.cyto_seg_name].attrs["cell_ids"]
+            ), "The nucleus segmentation mask and the cytosol segmentation mask must contain the same ids."
 
         # 2. the nucleus segmentation ids and the cytosol segmentation ids need to match
         # THIS NEEDS TO BE IMPLEMENTED HERE
@@ -1066,6 +1067,8 @@ def featurize(
         # setup overwrite if specified in call
         if overwrite is not None:
             self.featurization_f.overwrite_run_path = overwrite
+        if overwrite is None:
+            self.featurization_f.overwrite_run_path = True
 
         # update the number of masks that are available in the segmentation object
         self.featurization_f.n_masks = sum([self.nuc_seg_status, self.cyto_seg_status])
@@ -1079,7 +1082,6 @@ def select(
         self,
         cell_sets: list[dict],
         calibration_marker: np.ndarray | None = None,
-        segmentation_name: str = "seg_all_nucleus",
         name: str | None = None,
     ):
         """
@@ -1091,14 +1093,12 @@ def select(
 
         self._check_sdata_status()
 
-        if not self.nuc_seg_status or not self.cyto_seg_status:
+        if not self.nuc_seg_status and not self.cyto_seg_status:
             raise ValueError("No nucleus or cytosol segmentation loaded. Please load a segmentation first.")
 
         assert self.sdata is not None, "No sdata object loaded."
-        assert segmentation_name in self.sdata.labels, f"Segmentation {segmentation_name} not found in sdata object."
 
         self.selection_f(
-            segmentation_name=segmentation_name,
             cell_sets=cell_sets,
             calibration_marker=calibration_marker,
             name=name,
diff --git a/src/scportrait/pipeline/segmentation/segmentation.py b/src/scportrait/pipeline/segmentation/segmentation.py
index 9b2edcd..82e1e8f 100644
--- a/src/scportrait/pipeline/segmentation/segmentation.py
+++ b/src/scportrait/pipeline/segmentation/segmentation.py
@@ -85,6 +85,7 @@ def __init__(
         overwrite,
         project,
         filehandler,
+        from_project: bool = False,
         **kwargs,
     ):
         super().__init__(
@@ -95,6 +96,7 @@ def __init__(
             overwrite=overwrite,
             project=project,
             filehandler=filehandler,
+            from_project=from_project,
         )
 
         if self.directory is not None:
@@ -742,7 +744,6 @@ def _resolve_sharding(self, sharding_plan):
             local_hf = h5py.File(local_output, "r")
             local_hdf_labels = local_hf.get(self.DEFAULT_MASK_NAME)[:]
 
-            print(type(local_hdf_labels))
             shifted_map, edge_labels = shift_labels(
                 local_hdf_labels,
                 class_id_shift,
@@ -902,8 +903,9 @@ def _resolve_sharding(self, sharding_plan):
         if not self.deep_debug:
             self._cleanup_shards(sharding_plan)
 
-    def _initializer_function(self, gpu_id_list):
+    def _initializer_function(self, gpu_id_list, n_processes):
         current_process().gpu_id_list = gpu_id_list
+        current_process().n_processes = n_processes
 
     def _perform_segmentation(self, shard_list):
         # get GPU status
@@ -921,7 +923,7 @@ def _perform_segmentation(self, shard_list):
             with mp.get_context(self.context).Pool(
                 processes=self.n_processes,
                 initializer=self._initializer_function,
-                initargs=[self.gpu_id_list],
+                initargs=[self.gpu_id_list, self.n_processes],
             ) as pool:
                 list(
                     tqdm(
diff --git a/src/scportrait/pipeline/segmentation/workflows.py b/src/scportrait/pipeline/segmentation/workflows.py
index 008a272..b677597 100644
--- a/src/scportrait/pipeline/segmentation/workflows.py
+++ b/src/scportrait/pipeline/segmentation/workflows.py
@@ -653,7 +653,11 @@ def _check_for_mask_matching_filtering(self) -> None:
         else:
             # add deprecation warning for old config setup
             if "filter_status" in self.config.keys():
-                Warning("filter_status is deprecated, please use match_masks instead Will not perform filtering.")
+                self.filter_match_masks = True
+                self.mask_matching_filtering_threshold = 0.95
+                Warning(
+                    "filter_status is deprecated, please use match_masks instead. Will use default settings for mask matching."
+                )
 
             # default behaviour that this filtering should be performed, otherwise another additional step is required before extraction
             self.filter_match_masks = True
@@ -1349,6 +1353,9 @@ def _check_gpu_status(self):
             gpu_id_list = current.gpu_id_list
             cpu_id = int(cpu_name[cpu_name.find("-") + 1 :]) - 1
 
+            if cpu_id >= len(gpu_id_list):
+                cpu_id = cpu_id % current.n_processes
+
             # track gpu_id and update GPU status
             self.gpu_id = gpu_id_list[cpu_id]
             self.status = "multi_GPU"
diff --git a/src/scportrait/pipeline/selection.py b/src/scportrait/pipeline/selection.py
index 0afb36a..aa53235 100644
--- a/src/scportrait/pipeline/selection.py
+++ b/src/scportrait/pipeline/selection.py
@@ -1,10 +1,20 @@
+import multiprocessing as mp
 import os
+import pickle
+import timeit
+from functools import partial as func_partial
 
+import h5py
+import matplotlib.pyplot as plt
 import numpy as np
+import pandas as pd
 from alphabase.io import tempmmap
 from lmd.lib import SegmentationLoader
+from scipy.sparse import coo_array
+from tqdm.auto import tqdm
 
 from scportrait.pipeline._base import ProcessingStep
+from scportrait.pipeline._utils.helper import flatten
 
 
 class LMDSelection(ProcessingStep):
@@ -13,20 +23,60 @@ class LMDSelection(ProcessingStep):
     This method class relies on the functionality of the pylmd library.
     """
 
-    # define all valid path optimization methods used with the "path_optimization" argument in the configuration
-    VALID_PATH_OPTIMIZERS = ["none", "hilbert", "greedy"]
-
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
+        self._check_config()
 
         self.name = None
         self.cell_sets = None
         self.calibration_marker = None
 
-    def _setup_selection(self):
-        # set orientation transform
-        self.config["orientation_transform"] = np.array([[0, -1], [1, 0]])
+        self.deep_debug = False  # flag for deep debugging by developers
+
+    def _check_config(self):
+        assert "segmentation_channel" in self.config, "segmentation_channel not defined in config"
+        self.segmentation_channel_to_select = self.config["segmentation_channel"]
+
+        # check for optional config parameters
+
+        # this defines how large the box mask around the center of a cell is for the coordinate extraction
+        # assumption is that all pixels belonging to each mask are within the box otherwise they will be cut off during cutting contour generation
+
+        if "cell_width" in self.config:
+            self.cell_radius = self.config["cell_width"]
+        else:
+            self.cell_radius = 100
+
+        if "threads" in self.config:
+            self.threads = self.config["threads"]
+            assert self.threads > 0, "threads must be greater than 0"
+            assert isinstance(self.threads, int), "threads must be an integer"
+        else:
+            self.threads = 10
+
+        if "batch_size_coordinate_extraction" in self.config:
+            self.batch_size = self.config["batch_size_coordinate_extraction"]
+            assert self.batch_size > 0, "batch_size_coordinate_extraction must be greater than 0"
+            assert isinstance(self.batch_size, int), "batch_size_coordinate_extraction must be an integer"
+        else:
+            self.batch_size = 100
 
+        if "orientation_transform" in self.config:
+            self.orientation_transform = self.config["orientation_transform"]
+        else:
+            self.orientation_transform = np.array([[0, -1], [1, 0]])
+            self.config["orientation_transform"] = (
+                self.orientation_transform
+            )  # ensure its also in config so its passed on to the segmentation loader
+
+        if "processes_cell_sets" in self.config:
+            self.processes_cell_sets = self.config["processes_cell_sets"]
+            assert self.processes_cell_sets > 0, "processes_cell_sets must be greater than 0"
+            assert isinstance(self.processes_cell_sets, int), "processes_cell_sets must be an integer"
+        else:
+            self.processes_cell_sets = 1
+
+    def _setup_selection(self):
         # configure name of extraction
         if self.name is None:
             try:
@@ -39,6 +89,111 @@ def _setup_selection(self):
         savename = name.replace(" ", "_") + ".xml"
         self.savepath = os.path.join(self.directory, savename)
 
+        # check that the segmentation label exists
+        assert (
+            self.segmentation_channel_to_select in self.project.filehandler.get_sdata()._shared_keys
+        ), f"Segmentation channel {self.segmentation_channel_to_select} not found in sdata."
+
+    def __get_coords(
+        self, cell_ids: list, centers: list[tuple[int, int]], width: int = 60
+    ) -> list[tuple[int, np.ndarray]]:
+        results = []
+
+        _sdata = self.project.filehandler.get_sdata()
+        for i, _id in enumerate(cell_ids):
+            values = centers[i]
+
+            x_start = np.max([int(values[0]) - width, 0])
+            y_start = np.max([int(values[1]) - width, 0])
+
+            x_end = x_start + width * 2
+            y_end = y_start + width * 2
+
+            _cropped = _sdata[self.segmentation_channel_to_select][
+                slice(x_start, x_end), slice(y_start, y_end)
+            ].compute()
+
+            # optional plotting output for deep debugging
+            if self.deep_debug:
+                if self.threads == 1:
+                    plt.figure()
+                    plt.imshow(_cropped)
+                    plt.show()
+                else:
+                    raise ValueError("Deep debug is not supported with multiple threads.")
+
+            sparse = coo_array(_cropped == _id)
+
+            if (
+                0 in sparse.coords[0]
+                or 0 in sparse.coords[1]
+                or width * 2 - 1 in sparse.coords[0]
+                or width * 2 - 1 in sparse.coords[1]
+            ):
+                Warning(
+                    f"Cell {i} with id {_id} is potentially not fully contained in the bounding mask. Consider increasing the value for the 'cell_width' parameter in your config."
+                )
+
+            x = sparse.coords[0] + x_start
+            y = sparse.coords[1] + y_start
+
+            results.append((_id, np.array(list(zip(x, y, strict=True)))))
+
+        return results
+
+    def _get_coords_multi(self, width: int, arg: tuple[list[int], np.ndarray]) -> list[tuple[int, np.ndarray]]:
+        cell_ids, centers = arg
+        results = self.__get_coords(cell_ids, centers, width)
+        return results
+
+    def _get_coords(
+        self, cell_ids: list, centers: list[tuple[int, int]], width: int = 60, batch_size: int = 100, threads: int = 10
+    ) -> dict[int, np.ndarray]:
+        # create batches
+        n_batches = int(np.ceil(len(cell_ids) / batch_size))
+        slices = [(i * batch_size, i * batch_size + batch_size) for i in range(n_batches - 1)]
+        slices.append(((n_batches - 1) * batch_size, len(cell_ids)))
+
+        batched_args = [(cell_ids[start:end], centers[start:end]) for start, end in slices]
+
+        f = func_partial(self._get_coords_multi, width)
+
+        if (
+            threads == 1
+        ):  # if only one thread is used, the function is called directly to avoid the overhead of multiprocessing
+            results = [f(arg) for arg in batched_args]
+        else:
+            with mp.get_context(self.context).Pool(processes=threads) as pool:
+                results = list(
+                    tqdm(
+                        pool.imap(f, batched_args),
+                        total=len(batched_args),
+                        desc="Processing cell batches",
+                    )
+                )
+                pool.close()
+                pool.join()
+
+        results = flatten(results)  # type: ignore
+        return dict(results)  # type: ignore
+
+    def _get_cell_ids(self, cell_sets: list[dict]) -> list[int]:
+        cell_ids = []
+        for cell_set in cell_sets:
+            if "classes" in cell_set:
+                cell_ids.extend(cell_set["classes"])
+            else:
+                Warning(f"Cell set {cell_set['name']} does not contain any classes.")
+        return cell_ids
+
+    def _get_centers(self, cell_ids: list[int]) -> list[tuple[int, int]]:
+        _sdata = self.project.filehandler.get_sdata()
+        centers = _sdata["centers_cells"].compute()
+        centers = centers.loc[cell_ids, :]
+        return centers[
+            ["y", "x"]
+        ].values.tolist()  # needs to be returned as yx to match the coordinate system as saved in spatialdataobjects
+
     def _post_processing_cleanup(self, vars_to_delete: list | None = None):
         if vars_to_delete is not None:
             self._clear_cache(vars_to_delete=vars_to_delete)
@@ -51,7 +206,6 @@ def _post_processing_cleanup(self, vars_to_delete: list | None = None):
 
     def process(
         self,
-        segmentation_name: str,
         cell_sets: list[dict],
         calibration_marker: np.array,
         name: str | None = None,
@@ -61,9 +215,9 @@ def process(
         Under the hood this method relies on the pylmd library and utilizies its `SegmentationLoader` Class.
 
         Args:
-            segmentation_name (str): Name of the segmentation to be used for shape generation in the sdata object.
             cell_sets (list of dict): List of dictionaries containing the sets of cells which should be sorted into a single well. Mandatory keys for each dictionary are: name, classes. Optional keys are: well.
             calibration_marker (numpy.array): Array of size ‘(3,2)’ containing the calibration marker coordinates in the ‘(row, column)’ format.
+            name (str, optional): Name of the output file. If not provided, the name will be generated based on the names of the cell sets or if also not specified set to "selected_cells".
 
         Example:
 
@@ -77,7 +231,6 @@ def process(
                 # A numpy Array of shape (3, 2) should be passed.
                 calibration_marker = np.array([marker_0, marker_1, marker_2])
 
-
                 # Sets of cells can be defined by providing a name and a list of classes in a dictionary.
                 cells_to_select = [{"name": "dataset1", "classes": [1, 2, 3]}]
 
@@ -122,7 +275,7 @@ def process(
                     convolution_smoothing: 25
 
                     # fold reduction of datapoints for compression
-                    poly_compression_factor: 30
+                    rdp: 0.7
 
                     # Optimization of the cutting path inbetween shapes
                     # optimized paths improve the cutting time and the microscopes focus
@@ -160,32 +313,21 @@ def process(
 
         self._setup_selection()
 
-        ## TO Do
-        # check if classes and seglookup table already exist as pickle file
-        # if not create them
-        # else load them and proceed with selection
-
-        # load segmentation from hdf5
-        self.path_seg_mask = self.filehandler._load_seg_to_memmap(
-            [segmentation_name], tmp_dir_abs_path=self._tmp_dir_path
+        start_time = timeit.default_timer()
+        cell_ids = self._get_cell_ids(cell_sets)
+        centers = self._get_centers(cell_ids)
+        coord_index = self._get_coords(
+            cell_ids=cell_ids, centers=centers, width=self.cell_radius, batch_size=self.batch_size, threads=self.threads
         )
+        self.log(f"Coordinate lookup index calculation took {timeit.default_timer() - start_time} seconds.")
 
-        segmentation = tempmmap.mmap_array_from_path(self.path_seg_mask)
-
-        # create segmentation loader
         sl = SegmentationLoader(
             config=self.config,
             verbose=self.debug,
             processes=self.config["processes_cell_sets"],
         )
 
-        if len(segmentation.shape) == 3:
-            segmentation = np.squeeze(segmentation)
-        else:
-            raise ValueError(f"Segmentation shape is not correct. Expected 2D array, got {segmentation.shape}")
-
-        # get shape collections
-        shape_collection = sl(segmentation, self.cell_sets, self.calibration_marker)
+        shape_collection = sl(None, self.cell_sets, self.calibration_marker, coords_lookup=coord_index)
 
         if self.debug:
             shape_collection.plot(calibration=True)
@@ -196,4 +338,4 @@ def process(
         self.log(f"Saved output at {self.savepath}")
 
         # perform post processing cleanup
-        self._post_processing_cleanup(vars_to_delete=[shape_collection, sl, segmentation])
+        self._post_processing_cleanup(vars_to_delete=[shape_collection, sl, coord_index])
diff --git a/src/scportrait/tools/ml/transforms.py b/src/scportrait/tools/ml/transforms.py
index b976989..08baba1 100644
--- a/src/scportrait/tools/ml/transforms.py
+++ b/src/scportrait/tools/ml/transforms.py
@@ -19,7 +19,7 @@ def __init__(self, choices=4, include_zero=True):
             delta = (360 - angles[-1]) / 2
             angles = angles + delta
 
-        self.choices = angles
+        self.choices = angles.tolist()
 
     def __call__(self, tensor):
         angle = random.choice(self.choices)
diff --git a/src/scportrait/tools/stitch/_stitch.py b/src/scportrait/tools/stitch/_stitch.py
index 5b21148..e1020d6 100644
--- a/src/scportrait/tools/stitch/_stitch.py
+++ b/src/scportrait/tools/stitch/_stitch.py
@@ -21,12 +21,7 @@
 from scportrait.io.daskmmap import dask_array_from_path
 from scportrait.processing.images._image_processing import rescale_image
 from scportrait.tools.stitch._utils.ashlar_plotting import plot_edge_quality, plot_edge_scatter
-from scportrait.tools.stitch._utils.filereaders import (
-    BioformatsReaderRescale,
-    FilePatternReaderRescale,
-)
 from scportrait.tools.stitch._utils.filewriters import write_ome_zarr, write_spatialdata, write_tif, write_xml
-from scportrait.tools.stitch._utils.parallelized_ashlar import ParallelEdgeAligner, ParallelMosaic
 
 
 class Stitcher:
@@ -65,7 +60,7 @@ def __init__(
         do_intensity_rescale: bool | str = True,
         rescale_range: tuple = (1, 99),
         channel_order: list[str] = None,
-        reader_type=FilePatternReaderRescale,
+        reader_type="FilePatternReaderRescale",
         orientation: dict = None,
         plot_QC: bool = True,
         overwrite: bool = False,
@@ -114,6 +109,7 @@ def __init__(
 
         if orientation is None:
             orientation = {"flip_x": False, "flip_y": True}
+
         self.input_dir = input_dir
         self.slidename = slidename
         self.outdir = outdir
@@ -139,6 +135,10 @@ def __init__(
         self.orientation = orientation
         self.reader_type = reader_type
 
+        # workaround for lazy imports of module
+        if self.reader_type == "FilePatternReaderRescale":
+            self.reader_type = self.FilePatternReaderRescale
+
         # workflow setup
         self.plot_QC = plot_QC
         self.overwrite = overwrite
@@ -158,10 +158,20 @@ def _lazy_imports(self):
         from ashlar.reg import EdgeAligner, Mosaic
         from ashlar.scripts.ashlar import process_axis_flip
 
+        from scportrait.tools.stitch._utils.filereaders import (
+            BioformatsReaderRescale,
+            FilePatternReaderRescale,
+        )
+        from scportrait.tools.stitch._utils.parallelized_ashlar import ParallelEdgeAligner, ParallelMosaic
+
         self.ashlar_thumbnail = thumbnail
         self.ashlar_EdgeAligner = EdgeAligner
         self.ashlar_Mosaic = Mosaic
         self.ashlar_process_axis_flip = process_axis_flip
+        self.BioformatsReaderRescale = BioformatsReaderRescale
+        self.FilePatternReaderRescale = FilePatternReaderRescale
+        self.ParallelEdgeAligner = ParallelEdgeAligner
+        self.ParallelMosaic = ParallelMosaic
 
     def __exit__(self):
         self._clear_cache()
@@ -294,14 +304,14 @@ def _initialize_reader(self):
         """
         Initialize the reader for reading image tiles.
         """
-        if self.reader_type == FilePatternReaderRescale:
+        if self.reader_type == self.FilePatternReaderRescale:
             self.reader = self.reader_type(
                 self.input_dir,
                 self.pattern,
                 self.overlap,
                 rescale_range=self.rescale_range,
             )
-        elif self.reader_type == BioformatsReaderRescale:
+        elif self.reader_type == self.BioformatsReaderRescale:
             self.reader = self.reader_type(self.input_dir, rescale_range=self.rescale_range)
 
         # setup correct orientation of slide (this depends on microscope used to generate the data)
@@ -564,7 +574,7 @@ class ParallelStitcher(Stitcher):
         do_intensity_rescale (bool or "full_image", optional): Flag to indicate whether to rescale image intensities (default is True). Alternatively, set to "full_image" to rescale the entire image.
         rescale_range (tuple or dict, optional): If all channels should be rescaled to the same range pass a tuple with the percentiles for rescaling (default is (1, 99)). Alternatively, a dictionary can be passed with the channel names as keys and the percentiles as values if each channel should be rescaled to a different range.
         channel_order (list, optional): Order of channels in the generated output mosaic. If none (default value) the order of the channels is left unchanged.
-        reader_type (class, optional): Type of reader to use for reading image tiles (default is FilePatternReaderRescale).
+        reader_type (class, optional): Type of reader to use for reading image tiles (default is "FilePatternReaderRescale").
         orientation (dict, optional): Dictionary specifying which dimensions of the slide to flip (default is {'flip_x': False, 'flip_y': True}).
         plot_QC (bool, optional): Flag to indicate whether to plot quality control (QC) figures (default is True).
         overwrite (bool, optional): Flag to indicate whether to overwrite the output directory if it already exists (default is False).
@@ -588,7 +598,7 @@ def __init__(
         WGAchannel: str = None,
         channel_order: list[str] = None,
         overwrite: bool = False,
-        reader_type=FilePatternReaderRescale,
+        reader_type="FilePatternReaderRescale",
         orientation=None,
         cache: str = None,
         threads: int = 20,
@@ -613,8 +623,9 @@ def __init__(
             overwrite,
             cache,
         )
+
         # dirty fix to avoide multithreading error with BioformatsReader until this can be fixed
-        if self.reader_type == BioformatsReaderRescale:
+        if self.reader_type == self.BioformatsReaderRescale:
             threads = 1
             print(
                 "BioformatsReaderRescale does not support multithreading for calculating the error threshold currently. Proceeding with 1 thread."
@@ -632,7 +643,7 @@ def _initialize_aligner(self):
         Returns:
             aligner (ParallelEdgeAligner): Initialized ParallelEdgeAligner object.
         """
-        aligner = ParallelEdgeAligner(
+        aligner = self.ParallelEdgeAligner(
             self.reader,
             channel=self.stitching_channel_id,
             filter_sigma=self.filter_sigma,
@@ -644,7 +655,7 @@ def _initialize_aligner(self):
         return aligner
 
     def _initialize_mosaic(self):
-        mosaic = ParallelMosaic(
+        mosaic = self.ParallelMosaic(
             self.aligner, self.aligner.mosaic_shape, verbose=True, channels=self.channels, n_threads=self.threads
         )
         return mosaic