Add support of colorbar

satpy/tests/test_writers.py

@@ -24,6 +24,7 @@
 
 import numpy as np
 import xarray as xr
+from trollimage.colormap import greys
 
 try:
     from unittest import mock
@@ -584,7 +585,16 @@ def setUp(self):
                     'height': 30,
                     'bg': 'black',
                     'bg_opacity': 255,
-                    'line': 'white'}}
+                    'line': 'white'}},
+                {'scale': {
+                    'colormap': greys,
+                    'extend': False,
+                    'width': 1670, 'height': 110,
+                    'tick_marks': 5, 'minor_tick_marks': 1,
+                    'cursor': [0, 0], 'bg':'white',
+                    'title':'TEST TITLE OF SCALE',
+                    'fontsize': 110, 'align': 'cc'
+                }}
             ]
         }
 

satpy/writers/__init__.py

@@ -280,7 +280,7 @@ def add_overlay(orig_img, area, coast_dir, color=None, width=None, resolution=No
     return new_image
 
 
-def add_text(orig, dc, img, text=None):
+def add_text(orig, dc, img, text):
     """Add text to an image using the pydecorate package.
 
     All the features of pydecorate's ``add_text`` are available.
@@ -301,7 +301,7 @@ def add_text(orig, dc, img, text=None):
     return XRImage(new_data)
 
 
-def add_logo(orig, dc, img, logo=None):
+def add_logo(orig, dc, img, logo):
     """Add logos or other images to an image using the pydecorate package.
 
     All the features of pydecorate's ``add_logo`` are available.
@@ -322,6 +322,27 @@ def add_logo(orig, dc, img, logo=None):
     return XRImage(new_data)
 
 
+def add_scale(orig, dc, img, scale):
+    """Add scale to an image using the pydecorate package.
+
+    All the features of pydecorate's ``add_scale`` are available.
+    See documentation of :doc:`pydecorate:index` for more info.
+
+    """
+    LOG.info("Add scale to image.")
+
+    dc.add_scale(**scale)
+
+    arr = da.from_array(np.array(img) / 255.0, chunks=CHUNK_SIZE)
+
+    new_data = xr.DataArray(arr, dims=['y', 'x', 'bands'],
+                            coords={'y': orig.data.coords['y'],
+                                    'x': orig.data.coords['x'],
+                                    'bands': list(img.mode)},
+                            attrs=orig.data.attrs)
+    return XRImage(new_data)
+
+
 def add_decorate(orig, fill_value=None, **decorate):
     """Decorate an image with text and/or logos/images.
 
@@ -376,6 +397,8 @@ def add_decorate(orig, fill_value=None, **decorate):
                 img = add_logo(img, dc, img_orig, logo=dec['logo'])
             elif 'text' in dec:
                 img = add_text(img, dc, img_orig, text=dec['text'])
+            elif 'scale' in dec:
+                img = add_scale(img, dc, img_orig, scale=dec['scale'])
     return img