diff --git a/src/python/app/command/parser.py b/src/python/app/command/parser.py
index d4abc8e..48fe02e 100644
--- a/src/python/app/command/parser.py
+++ b/src/python/app/command/parser.py
@@ -12,8 +12,6 @@
 from app.operation.roll import RollOperation
 
 from app.operation.rotate90 import Rotate90Operation
-from app.operation.scale import ScaleOperation
-from app.operation.translate import TranslateOperation
 
 
 def get_parser() -> ArgumentParser:
diff --git a/src/python/app/operation/grayscale.py b/src/python/app/operation/grayscale.py
index 0163aee..512d5be 100644
--- a/src/python/app/operation/grayscale.py
+++ b/src/python/app/operation/grayscale.py
@@ -23,10 +23,12 @@ def parser(cls, parser: ArgumentParser) -> None:
         pass
 
     def __call__(self, args: Namespace, input_image: Image) -> Image:
-        return Image(np.expand_dims(np.clip(
+        return Image(np.repeat(np.expand_dims(np.clip(
             0.2126 * input_image.data[:, :, 0]
             + 0.7152 * input_image.data[:, :, 1]
             + 0.0722 * input_image.data[:, :, 1],
             a_min=0.,
             a_max=255.).astype(np.uint8),
+            axis=-1),
+            repeats=3,
             axis=-1))