Changeset 5515 for spike/wktraster/scripts/gdal2wktraster.py

Timestamp:

04/08/10 11:36:39 (2 years ago)

Author:

pracine

Message:

Ticket 188. Implement a HasNoDataValue? function. Set the HasNodata? flag from gdal2wktraster.py.

Files:

• spike/wktraster/scripts/gdal2wktraster.py (modified) (4 diffs)

spike/wktraster/scripts/gdal2wktraster.py

@@ -639 +639 @@
         nodata = band.GetNoDataValue()
     else:
-        # FIXME: What if input dataset does not specify NODATA value? Zero?
         logit("WARNING: No NODATA flagged in raster_columns metadata. "
               "In serialized raster, NODATA bytes will have value of 0.\n")
@@ -709 +708 @@
     return hexwkb
 
-def wkblify_band_nodata(band):
-    assert band is not None
-
-    pixtype = gdt2pt(band.DataType)['id']
-    nodata = fetch_band_nodata(band)
-
-    hexwkb = ''
-    hexwkb += wkblify(pt2fmt(pixtype), nodata)
-
-    return hexwkb
-
 def wkblify_band_header(options, band):
     """Writes band header into HEX-encoded WKB"""
@@ -726 +714 @@
     hexwkb = ""
 
+    first4bits = 0
+    
+    # If the register option is enabled, set the first bit to 1
+    if options.register:
+        first4bits = 128
+        
+    nodata = band.GetNoDataValue()
+    # If there is no nodata value, set it to 0. Otherwise set the HasNodata bit to 1
+    if nodata is not None:
+        first4bits += 64
+    else:
+        nodata = 0
+    
     # Encode pixel type
     pixtype = gdt2pt(band.DataType)['id']
-    if options.register:
-        hexwkb += wkblify('B', pixtype + 128)
-    else:
-        hexwkb += wkblify('B', pixtype)
+    hexwkb += wkblify('B', pixtype + first4bits)
     
     # Encode NODATA value (or Zero, if NODATA unavailable) 
-    hexwkb += wkblify_band_nodata(band)
+    hexwkb += wkblify(pt2fmt(pixtype), nodata)
 
     check_hex(hexwkb)
@@ -758 +756 @@
     else:
         # In-db raster
-
-        # Real NODATA value or Zero'ed byte(s)
-        hexnodata = wkblify_band_nodata(band)
-        bytes_per_pixel = len(hexnodata) / 2 # bytes per pixel used to validate hex string
 
         # Right most column and bottom most row of blocks have