Add WithPolarWarping

changelogs/master/added/20191110_bb_polygon_conversion.md

@@ -0,0 +1,5 @@
+# Bounding Box to Polygon Conversion #489
+
+* Added method `imgaug.augmentables.bbs.BoundingBox.to_polygon()`.
+* Added method
+  `imgaug.augmentables.bbs.BoundingBoxesOnImage.to_polygons_on_image()`.

changelogs/master/added/20191110_polygon_subdivision.md

@@ -0,0 +1,6 @@
+# Added Polygon Subdivision #489
+
+* Added method `imgaug.augmentables.polys.Polygon.subdivide(N)`.
+  The method increases the polygon's corner point count by interpolating
+  `N` points on each edge with regular distance.
+* Added method `imgaug.augmentables.polys.PolygonsOnImage.subdivide(N)`.

changelogs/master/added/20191110_withpolarwarping.md

@@ -0,0 +1,5 @@
+# Added `WithPolarWarping` #489
+
+* Added augmenter `imgaug.augmenters.geometric.WithPolarWarping`, an
+  augmenter that applies child augmenters in a polar representation of the
+  image.

changelogs/master/changed/20191110_affine_translation_precision.md

@@ -0,0 +1,5 @@
+# Affine Translation Precision #489
+
+* Removed a rounding operation in `Affine` translation that would unnecessarily
+  round floats to integers. This should make coordinate augmentation overall
+  more accurate.

changelogs/master/fixed/20191110_fixed_affine_map_aug.md

@@ -0,0 +1,5 @@
+# Fixed Affine Translation of Map-Data #489
+
+* Fixed `Affine` producing unaligned augmentations between images and
+  segmentation maps or heatmaps when using `translate_px` and the segmentation
+  map or heatmap had a different height/width than corresponding image.

imgaug/augmentables/bbs.py

@@ -761,6 +761,7 @@ def extract_from_image(self, image, pad=True, pad_max=None,
 
     # TODO also add to_heatmap
     # TODO add this to BoundingBoxesOnImage
+    # TODO add label to keypoints?
     def to_keypoints(self):
         """Convert the BB's corners to keypoints (clockwise, from top left).
 
@@ -780,6 +781,25 @@ def to_keypoints(self):
             Keypoint(x=self.x1, y=self.y2)
         ]
 
+    def to_polygon(self):
+        """Convert this bounding box to a polygon covering the same area.
+
+        Returns
+        -------
+        imgaug.augmentables.polys.Polygon
+            The bounding box converted to a polygon.
+
+        """
+        # TODO get rid of this deferred import
+        from imgaug.augmentables.polys import Polygon
+
+        return Polygon([
+            (self.x1, self.y1),
+            (self.x2, self.y1),
+            (self.x2, self.y2),
+            (self.x1, self.y2)
+        ], label=self.label)
+
     def coords_almost_equals(self, other, max_distance=1e-4):
         """Estimate if this and another BB have almost identical coordinates.
 
@@ -1458,6 +1478,21 @@ def invert_to_keypoints_on_image_(self, kpsoi):
         self.shape = kpsoi.shape
         return self
 
+    def to_polygons_on_image(self):
+        """Convert the bounding boxes to one ``PolygonsOnImage`` instance.
+
+        Returns
+        -------
+        imgaug.augmentables.polys.PolygonsOnImage
+            A ``PolygonsOnImage`` containing polygons. Each polygon covers
+            the same area as the corresponding bounding box.
+
+        """
+        from .polys import PolygonsOnImage
+
+        polygons = [bb.to_polygon() for bb in self.bounding_boxes]
+        return PolygonsOnImage(polygons, shape=self.shape)
+
     def copy(self):
         """Create a shallow copy of the ``BoundingBoxesOnImage`` instance.
 

imgaug/augmentables/polys.py

@@ -905,6 +905,30 @@ def change_first_point_by_index(self, point_idx):
         )
         return self.deepcopy(exterior=exterior)
 
+    def subdivide(self, points_per_edge):
+        """Derive a new polygon with ``N`` interpolated points per edge.
+
+        See :func:`imgaug.augmentables.lines.LineString.subdivide` for details.
+
+        Parameters
+        ----------
+        points_per_edge : int
+            Number of points to interpolate on each edge.
+
+        Returns
+        -------
+        imgaug.augmentables.polys.Polygon
+            Polygon with subdivided edges.
+
+        """
+        if len(self.exterior) == 1:
+            return self.deepcopy()
+        ls = self.to_line_string(closed=True)
+        ls_sub = ls.subdivide(points_per_edge)
+        # [:-1] even works if the polygon contains zero points
+        exterior_subdivided = ls_sub.coords[:-1]
+        return Polygon(exterior_subdivided, label=self.label)
+
     def to_shapely_polygon(self):
         """Convert this polygon to a ``Shapely`` ``Polygon``.
 
@@ -1495,6 +1519,23 @@ def shift(self, top=None, right=None, bottom=None, left=None):
         ]
         return PolygonsOnImage(polys_new, shape=self.shape)
 
+    def subdivide(self, points_per_edge):
+        """Interpolate ``N`` points on each polygon.
+
+        Parameters
+        ----------
+        points_per_edge : int
+            Number of points to interpolate on each edge.
+
+        Returns
+        -------
+        imgaug.augmentables.polys.PolygonsOnImage
+            Subdivided polygons.
+
+        """
+        polys_new = [poly.subdivide(points_per_edge) for poly in self.polygons]
+        return PolygonsOnImage(polys_new, shape=self.shape)
+
     def to_xy_array(self):
         """Convert all polygon coordinates to one array of shape ``(N,2)``.