diff --git a/hexrd/imageseries/load/__init__.py b/hexrd/imageseries/load/__init__.py
index 7f1d3105d..c11cf49c8 100644
--- a/hexrd/imageseries/load/__init__.py
+++ b/hexrd/imageseries/load/__init__.py
@@ -19,7 +19,7 @@ class ImageSeriesAdapter(ImageSeriesABC, metaclass=_RegisterAdapterClass):
 # import all adapter modules
 
 from . import (
-    array, framecache, hdf5, imagefiles, rawimage, metadata, trivial
+    array, framecache, function, hdf5, imagefiles, rawimage, metadata, trivial
 )
 
 try:
diff --git a/hexrd/imageseries/load/function.py b/hexrd/imageseries/load/function.py
new file mode 100644
index 000000000..6356cc20c
--- /dev/null
+++ b/hexrd/imageseries/load/function.py
@@ -0,0 +1,60 @@
+"""Adapter class for a custom function that takes an int as an argument
+and returns a 2D numpy array.
+"""
+from . import ImageSeriesAdapter
+from ..imageseriesiter import ImageSeriesIterator
+
+
+class FunctionImageSeriesAdapter(ImageSeriesAdapter):
+    """Collection of Images in numpy array
+
+    Parameters
+    ----------
+    fname: None
+       should be None
+    func: a function that returns a numpy array for a index
+    num_frames: the number of frames provided by the function
+    metadata: dict (optional)
+       the metadata dictionary
+    """
+    format = 'function'
+
+    def __init__(self, fname, **kwargs):
+        self._func = kwargs['func']
+        self._nframes = kwargs['num_frames']
+
+        self._meta = kwargs.pop('meta', {})
+
+        first_frame = self._first_frame
+        self._nxny = first_frame.shape
+        self._dtype = first_frame.dtype
+
+    @property
+    def metadata(self):
+        """Image sequence metadata"""
+        return self._meta
+
+    @property
+    def _first_frame(self):
+        return self._func(0)
+
+    @property
+    def shape(self):
+        return self._nxny
+
+    @property
+    def dtype(self):
+        return self._dtype
+
+    def __getitem__(self, key):
+        if not isinstance(key, int):
+            msg = f'Only int keys are supported, but "{key}" was provided'
+            raise Exception(msg)
+
+        return self._func(key)
+
+    def __iter__(self):
+        return ImageSeriesIterator(self)
+
+    def __len__(self):
+        return self._nframes