Make default behavior follow previous implementation.

doc/stages/filters.colorization.rst

@@ -44,8 +44,7 @@ dimensions
   Either or both of band number and scale factor may be omitted as may ':'
   separators if the data is not ambiguous.  If not supplied, band numbers
   begin at 1 and increment from the band number of the previous dimension.
-  If not supplied, the scaling factor is 1.0.  If fewer than three dimensions
-  are supplied, the defaults are applied where appropriate.
+  If not supplied, the scaling factor is 1.0.
   [Default: "Red:1:1.0, Green:2:1.0, Blue:3:1.0"]
 
 .. _GDAL: http://gdal.org

filters/colorization/ColorizationFilter.cpp

@@ -149,19 +149,20 @@ void ColorizationFilter::processOptions(const Options& options)
         throw pdal_error("Option 'dimension' no longer supported.  Use "
             "'dimensions' instead.");
 
-    StringList dims = options.getValueOrDefault<StringList>("dimensions");
+    StringList defaultDims;
+    defaultDims.push_back("Red");
+    defaultDims.push_back("Green");
+    defaultDims.push_back("Blue");
 
-    m_bands.emplace_back("Red", 1, 1.0);
-    m_bands.emplace_back("Green", 2, 1.0);
-    m_bands.emplace_back("Blue", 3, 1.0);
+    StringList dims =
+        options.getValueOrDefault<StringList>("dimensions", defaultDims);
 
-    size_t i = 0;
     uint32_t defaultBand = 1;
     for (std::string& dim : dims)
     {
         BandInfo bi = parseDim(dim, defaultBand);
         defaultBand = bi.m_band + 1;
-        m_bands[i++] = bi;
+        m_bands.push_back(bi);
     }
 }