diff --git a/src/ffx/filter/crop_filter.py b/src/ffx/filter/crop_filter.py
index 468c419..c41f614 100644
--- a/src/ffx/filter/crop_filter.py
+++ b/src/ffx/filter/crop_filter.py
@@ -24,10 +24,10 @@ class CropFilter(Filter):
 
     def __init__(self, **kwargs):
         
-        self.__outputWidth = int(kwargs.get(CropFilter.OUTPUT_WIDTH_KEY))
-        self.__outputHeight = int(kwargs.get(CropFilter.OUTPUT_HEIGHT_KEY))
-        self.__offsetX = int(kwargs.get(CropFilter.OFFSET_X_KEY))
-        self.__offsetY = int(kwargs.get(CropFilter.OFFSET_Y_KEY))
+        self.__outputWidth = int(kwargs.get(CropFilter.OUTPUT_WIDTH_KEY, 0))
+        self.__outputHeight = int(kwargs.get(CropFilter.OUTPUT_HEIGHT_KEY, 0))
+        self.__offsetX = int(kwargs.get(CropFilter.OFFSET_X_KEY, 0))
+        self.__offsetY = int(kwargs.get(CropFilter.OFFSET_Y_KEY, 0))
 
         super().__init__(self)