Use a dict to encode the list of channels and dtypes.

Signed-off-by: Chris Lalancette <[email protected]>

Author: clalancette

image_tools_py/src/cam2image_py.py

@@ -47,19 +47,20 @@ def flip_image_cb(msg):
 # sensor_msgs::Image
 def mat2encoding(frame):
     encoding = ''
-    if frame.shape[2] == 1:
-        encoding += 'mono'
-    elif frame.shape[2] == 3:
-        encoding += 'bgr'
-    elif frame.shape[2] == 4:
-        encoding += 'rgba'
+
+    encodings = {1:'mono', 3:'bgr', 4:'rgba'}
+    for channels, prefix in encodings.items():
+        if frame.shape[2] == channels:
+            encoding += prefix
+            break
     else:
         raise Exception("Unsupported frame shape %d" % (frame.shape[2]))
 
-    if frame.dtype == 'uint8':
-        encoding += '8'
-    elif frame.dtype == 'int16':
-        encoding += '16'
+    types = {'uint8':'8', 'int16':'16'}
+    for dtype, num in types.items():
+        if frame.dtype == dtype:
+            encoding += num
+            break
     else:
         raise Exception("Unsupported frame type " + frame.dtype)
 

image_tools_py/src/showimage_py.py

@@ -30,19 +30,17 @@
 
 
 def encoding2mat(encoding):
-    if encoding.startswith('mono'):
-        channels = 1
-    elif encoding.startswith('bgr'):
-        channels = 3
-    elif encoding.startswith('rgba'):
-        channels = 4
+    encodings = {'mono' : 1, 'bgr' : 3, 'rgba' : 4}
+    for prefix, channels in encodings.items():
+        if encoding.startswith(prefix):
+            break
     else:
         raise Exception("Unsupported encoding " + encoding)
 
-    if encoding[channels:] == '8':
-        dtype = 'uint8'
-    elif encoding[channels:] == '16':
-        dtype = 'int16'
+    types = {'8' : 'uint8', '16' : 'int16'}
+    for prefix, dtype in types.items():
+        if encoding[channels:] == prefix:
+            break
     else:
         raise Exception("Unsupported encoding " + encoding)