Fixed issue 44 (SSIM filtering flags too much tie points in case of completely...

Fixed issue 44 (SSIM filtering flags too much tie points in case of completely different data ranges of the input images). Bumped version.
Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>

arosics/CoReg.py

@@ -52,7 +52,6 @@ from py_tools_ds.geo.coord_grid import move_shapelyPoly_to_image_grid, is_coord_
 from py_tools_ds.geo.coord_trafo import reproject_shapelyGeometry, mapXY2imXY, imXY2mapXY
 from py_tools_ds.geo.raster.reproject import warp_ndarray
 from py_tools_ds.geo.map_info import geotransform2mapinfo
-from py_tools_ds.similarity.raster import calc_ssim
 from py_tools_ds.io.vector.writer import write_shp
 
 __author__ = 'Daniel Scheffler'
@@ -310,6 +309,7 @@ class COREG(object):
         self.success = None  # default
         self.deshift_results = None  # set by self.correct_shifts()
 
+        # try:
         gdal.AllRegister()
         self._get_image_params()
         self._set_outpathes(im_ref, im_tgt)
@@ -338,6 +338,9 @@ class COREG(object):
                       self.matchBox.mapPoly, self.matchBox.prj)
 
         self.success = False if self.success is False or not self.matchBox.boxMapYX else None
+
+        # except BaseException:
+
         self._coreg_info = None  # private attribute to be filled by self.coreg_info property
 
     def _handle_error(self, error, warn=False, warnMsg=None):
@@ -1212,26 +1215,42 @@ class COREG(object):
         return ds_results['GeoArray_shifted']
 
     def _validate_ssim_improvement(self, v=False):
-        """Compute mean structural similarity index between reference and target image before and after co-regsitration.
+        """Compute mean structural similarity index between reference and target image before and after co-registration.
 
         :param v:   <bool> verbose mode: shows images of the matchWin, otherWin and shifted version of otherWin
         :return:    <tuple> SSIM before an after shift correction
         """
+        from skimage.metrics import structural_similarity as ssim  # import here to avoid static TLS import error
+
         assert self.success is not None, \
             'Calculate geometric shifts first before trying to measure image similarity improvement!'
         assert self.success in [True, None], \
             'Since calculation of geometric shifts failed, no image similarity improvement can be measured.'
 
-        # get image dynamic range
-        dr = max(self.matchWin[:].max(), self.otherWin[:].max()) - \
-            min(self.matchWin[:].min(), self.otherWin[:].min())
+        def normalize(array):
+            # type: (np.ndarray) -> np.ndarray
+            minval = np.min(array)
+            maxval = np.max(array)
+
+            # avoid zerodivision
+            if maxval == minval:
+                maxval += 1e-5
+
+            return ((array - minval) / (maxval - minval)).astype(np.float64)
+
+        # compute SSIM BEFORE shift correction #
+        ########################################
 
-        # compute SSIM BEFORE shift correction
         # using gaussian weights could lead to value errors in case of small images when the automatically calulated
         # window size exceeds the image size
-        self.ssim_orig = calc_ssim(self.matchWin[:], self.otherWin[:], dynamic_range=dr)
+        self.ssim_orig = ssim(normalize(np.ma.masked_equal(self.matchWin[:],
+                                                           self.matchWin.nodata)),
+                              normalize(np.ma.masked_equal(self.otherWin[:],
+                                                           self.otherWin.nodata)),
+                              data_range=1)
 
-        # compute SSIM AFTER shift correction
+        # compute SSIM AFTER shift correction #
+        #######################################
 
         # resample otherWin while correcting detected shifts and match geographic bounds of matchWin
         otherWin_deshift_geoArr = self._get_deshifted_otherWin()
@@ -1243,27 +1262,39 @@ class COREG(object):
         # the exact same dimensions as self.matchWin -> maybe bounds are handled differently by gdal.Warp)
         if not self.matchWin.shape == otherWin_deshift_geoArr.shape:  # FIXME this seems to be already fixed
             warnings.warn('SSIM input array shapes are not equal! This issue seemed to be already fixed.. ')
-            matchFull = self.ref if self.matchWin.imID == 'ref' else self.shift
-            matchWinData, _, _ = matchFull.get_mapPos(self.matchBox.mapPoly.bounds, self.matchWin.prj,
-                                                      rspAlg='cubic', band2get=matchFull.band4match)
+            matchFull = \
+                self.ref if self.matchWin.imID == 'ref' else\
+                self.shift
+            matchWinData, _, _ = matchFull.get_mapPos(self.matchBox.mapPoly.bounds,
+                                                      self.matchWin.prj,
+                                                      rspAlg='cubic',
+                                                      band2get=matchFull.band4match)
             self.matchWin.clip_to_poly(self.matchBox.mapPoly)
 
-            # at the image edges it is possible that the size of the matchBox must be reduced in order to make array
-            # shapes match
+            # at the image edges it is possible that the size of the matchBox must be reduced
+            # in order to make array shapes match
             if not matchWinData.shape == otherWin_deshift_geoArr.shape:  # FIXME this seems to be already fixed
-                self.matchBox.buffer_imXY(float(-np.ceil(abs(self.x_shift_px))), float(-np.ceil(abs(self.y_shift_px))))
+                self.matchBox.buffer_imXY(float(-np.ceil(abs(self.x_shift_px))),
+                                          float(-np.ceil(abs(self.y_shift_px))))
                 otherWin_deshift_geoArr = self._get_deshifted_otherWin()
-                matchWinData, _, _ = matchFull.get_mapPos(self.matchBox.mapPoly.bounds, self.matchWin.prj,
-                                                          rspAlg='cubic', band2get=matchFull.band4match)
+                matchWinData, _, _ = matchFull.get_mapPos(self.matchBox.mapPoly.bounds,
+                                                          self.matchWin.prj,
+                                                          rspAlg='cubic',
+                                                          band2get=matchFull.band4match)
 
             # output validation
             if not matchWinData.shape == otherWin_deshift_geoArr.shape:
-                warnings.warn('SSIM input array shapes could not be equalized. SSIM calculation failed. SSIM of the '
-                              'de-shifted target image is set to 0.')
+                warnings.warn('SSIM input array shapes could not be equalized. SSIM calculation failed. '
+                              'SSIM of the de-shifted target image is set to 0.')
                 self.ssim_deshifted = 0
+
                 return self.ssim_orig, self.ssim_deshifted
 
-        self.ssim_deshifted = calc_ssim(otherWin_deshift_geoArr[:], matchWinData, dynamic_range=dr)
+        self.ssim_deshifted = ssim(normalize(np.ma.masked_equal(otherWin_deshift_geoArr[:],
+                                                                otherWin_deshift_geoArr.nodata)),
+                                   normalize(np.ma.masked_equal(matchWinData,
+                                                                self.matchWin.nodata)),
+                                   data_range=1)
 
         if v:
             GeoArray(matchWinData).show()

arosics/version.py

@@ -22,5 +22,5 @@
 # with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-__version__ = '1.1.1'
-__versionalias__ = '2020-11-02_01'
+__version__ = '1.2.0'
+__versionalias__ = '2020-11-02_02'