Revert some PNG generation logic

opendm/orthophoto.py

@@ -44,30 +44,26 @@ def generate_png(orthophoto_file, output_file=None, outsize=None):
     
     # See if we need to select top three bands
     bandparam = ""
+
     gtif = gdal.Open(orthophoto_file)
     if gtif.RasterCount > 4:
-        try:
-            bands = []
-            for idx in range(1, gtif.RasterCount+1):
-                bands.append(gtif.GetRasterBand(idx).GetColorInterpretation())
+        bands = []
+        for idx in range(1, gtif.RasterCount+1):
+            bands.append(gtif.GetRasterBand(idx).GetColorInterpretation())
+        bands = dict(zip(bands, range(1, len(bands)+1)))
 
-            bands = dict(zip(bands, range(1, len(bands)+1)))
-            red = bands.get(3)
-            green = bands.get(4)
-            blue = bands.get(5)
-            alpha = bands.get(6)
-            if alpha is not None:
-                bandparam = "-b %s -b %s -b %s -b %s -a_nodata 0" % (red, green, blue, alpha)
-            else:
-                bandparam = "-b %s -b %s -b %s -a_nodata 0" % (red, green, blue)
-        except Exception as e:
+        try:
+            red = bands.get(gdal.GCI_RedBand)
+            green = bands.get(gdal.GCI_GreenBand)
+            blue = bands.get(gdal.GCI_BlueBand)
+            bandparam = "-b %s -b %s -b %s -a_nodata 0" % (red, green, blue)
+        except:
             bandparam = "-b 1 -b 2 -b 3 -a_nodata 0"
+    gtif = None
 
     osparam = ""
     if outsize is not None:
-        osparam = "-outsize %s 0 -ot Byte -scale 0 0.5 0 255" % outsize
-    else:
-        osparam = "-outsize %s%% %s%% ot Byte -scale 0 0.5 0 255" % (10, 10)
+        osparam = "-outsize %s 0" % outsize
 
     system.run('gdal_translate -of png "%s" "%s" %s %s '
                '--config GDAL_CACHEMAX %s%% ' % (orthophoto_file, output_file, osparam, bandparam, get_max_memory()))