Added Accessor method to handle YX cropping

model_server/base/accessors.py

@@ -85,6 +85,15 @@ class GenericImageDataAccessor(ABC):
     def _ga(self, arg):
         return self.get_axis(arg)
 
+    def crop_hw(self, yxhw: tuple):
+        """
+        Return subset of data cropped in X and Y
+        :param yxhw: tuple (Y, X, H, W)
+        :return: InMemoryDataAccessor of size (H x W), starting at (Y, X)
+        """
+        y, x, h, w = yxhw
+        return InMemoryDataAccessor(self.data[y: (y + h), x: (x + w), :, :])
+
     @property
     def hw(self):
         """

tests/base/test_accessors.py

@@ -73,6 +73,19 @@ class TestCziImageFileAccess(unittest.TestCase):
 
         self.assertTrue(np.all(sz.data[:, :, :, 0] == cf.data[:, :, :, zi]))
 
+    def test_crop_yx(self):
+        w = 256
+        h = 512
+        nc = 4
+        nz = 11
+        cf = InMemoryDataAccessor(_random_int(h, w, nc, nz))
+
+        yxhw = (100, 200, 10, 20)
+        sc = cf.crop_hw(yxhw)
+        self.assertEqual(sc.shape_dict['Z'], nz)
+        self.assertEqual(sc.shape_dict['C'], nc)
+        self.assertEqual(sc.hw, yxhw[2:])
+
     def test_write_single_channel_tif(self):
         ch = 4
         cf = CziImageFileAccessor(data['czifile']['path'])