Update image types docval to add more clarity to dimension order (#1418)

Co-authored-by: Ryan Ly <[email protected]>

CHANGELOG.md

@@ -5,11 +5,15 @@
 ### Bug fixes:
 - Add `environment-ros3.yml` to `MANIFEST.in` for inclusion in source distributions. @rly (#1398)
 - Fix bad error check in ``IntracellularRecordingsTable.add_recording`` when adding ``IZeroClampSeries``. @oruebel (#1410)
--  Skip ros3 tests if internet access or the ros3 driver are not available. @oruebel (#1414)
+- Skip ros3 tests if internet access or the ros3 driver are not available. @oruebel (#1414)
 
 ### Tutorial enhancements:
 - Updated the general tutorial to add documentation about the ``Images`` type. @bendichter (#1353)
 
+### Minor improvements:
+- Improve constructor docstrings for Image types. @weiglszonja (#1418)
+
+
 ## PyNWB 2.0.0 (August 13, 2021)
 
 ### Breaking changes:

src/pynwb/image.py

@@ -193,7 +193,8 @@ def __init__(self, **kwargs):
 class GrayscaleImage(Image):
 
     @docval(*get_docval(Image.__init__, 'name'),
-            {'name': 'data', 'type': ('array_data', 'data'), 'doc': 'Data of image. Must be 2D',
+            {'name': 'data', 'type': ('array_data', 'data'),
+             'doc': 'Data of grayscale image. Must be 2D where the dimensions represent x and y.',
              'shape': (None, None)},
             *get_docval(Image.__init__, 'resolution', 'description'))
     def __init__(self, **kwargs):
@@ -205,7 +206,8 @@ class RGBImage(Image):
 
     @docval(*get_docval(Image.__init__, 'name'),
             {'name': 'data', 'type': ('array_data', 'data'),
-             'doc': 'Data of image. Must be 3D where the third dimension has length 3 and represents the RGB value',
+             'doc': 'Data of color image. Must be 3D where the first and second dimensions represent x and y. '
+                    'The third dimension has length 3 and represents the RGB value.',
              'shape': (None, None, 3)},
             *get_docval(Image.__init__, 'resolution', 'description'))
     def __init__(self, **kwargs):
@@ -217,7 +219,8 @@ class RGBAImage(Image):
 
     @docval(*get_docval(Image.__init__, 'name'),
             {'name': 'data', 'type': ('array_data', 'data'),
-             'doc': 'Data of image. Must be 3D where the third dimension has length 4 and represents the RGBA value',
+             'doc': 'Data of color image with transparency. Must be 3D where the first and second dimensions '
+                    'represent x and y. The third dimension has length 4 and represents the RGBA value.',
              'shape': (None, None, 4)},
             *get_docval(Image.__init__, 'resolution', 'description'))
     def __init__(self, **kwargs):