use python API to get raster extent, instead of relying on gdalinfo

etiennesky · etiennesky · commit 4b9e181e23c2 · 2014-01-30T11:42:00.000-02:00
diff --git a/python/plugins/GdalTools/tools/GdalTools_utils.py b/python/plugins/GdalTools/tools/GdalTools_utils.py
@@ -306,35 +306,26 @@ def getRasterSRS( parent, fileName ):
 
     return ''
 
+# get raster extent using python API - replaces old method which parsed gdalinfo output
 def getRasterExtent(parent, fileName):
-    processSRS = QProcess( parent )
-    processSRS.start( "gdalinfo", [fileName], QIODevice.ReadOnly )
-    arr = ''
-    if processSRS.waitForFinished():
-      arr = str(processSRS.readAllStandardOutput())
-      processSRS.close()
-
-    if arr == '':
-      return
-
-    ulCoord = lrCoord = ''
-    xUL = yLR = xLR = yUL = 0
-    info = arr.splitlines()
-    for elem in info:
-        m = re.match("^Upper\sLeft.*", elem)
-        if m:
-            ulCoord = m.group(0).strip()
-            ulCoord = ulCoord[string.find(ulCoord,"(") + 1 : string.find(ulCoord,")") - 1].split( "," )
-            xUL = float(ulCoord[0])
-            yUL = float(ulCoord[1])
-            continue
-        m = re.match("^Lower\sRight.*", elem)
-        if m:
-            lrCoord = m.group(0).strip()
-            lrCoord = lrCoord[string.find(lrCoord,"(") + 1 : string.find(lrCoord,")") - 1].split( "," )
-            xLR = float(lrCoord[0])
-            yLR = float(lrCoord[1])
-            continue
+    ds = gdal.Open(fileName)
+    if ds is None:
+        return
+
+    x = ds.RasterXSize
+    y = ds.RasterYSize
+
+    gt = ds.GetGeoTransform()
+    if gt is None:
+        xUL = 0
+        yUL = 0
+        xLR = x
+        yLR = y
+    else:
+        xUL = gt[0]
+        yUL = gt[3]
+        xLR = gt[0] + gt[1]*x + gt[2]*y
+        yLR = gt[3] + gt[4]*x + gt[5]*y
 
     return QgsRectangle( xUL, yLR, xLR, yUL )
 
