diff --git a/app/api/hillshade.py b/app/api/hillshade.py index 500062281..6bfab9837 100644 --- a/app/api/hillshade.py +++ b/app/api/hillshade.py @@ -71,12 +71,6 @@ def hillshade(self, elevation, vert_exag=1, dx=1, dy=1, fraction=1.): A 2d array of illumination values between 0-1, where 0 is completely in shadow and 1 is completely illuminated. """ - - # Because most image and raster GIS data has the first row in the array - # as the "top" of the image, dy is implicitly negative. This is - # consistent to what `imshow` assumes, as well. - dy = -dy - # compute the normal vectors from the partial derivatives e_dy, e_dx = np.gradient(vert_exag * elevation, dy, dx) @@ -115,19 +109,19 @@ def shade_normals(self, normals, fraction=1.): intensity = normals.dot(self.direction.astype(np.float32)) # Apply contrast stretch - imin, imax = intensity.min(), intensity.max() + # imin, imax = np.nanmin(intensity), np.nanmax(intensity) intensity *= fraction # Rescale to 0-1, keeping range before contrast stretch # If constant slope, keep relative scaling (i.e. flat should be 0.5, # fully occluded 0, etc.) - if (imax - imin) > 1e-6: + # if (imax - imin) > 1e-6: # Strictly speaking, this is incorrect. Negative values should be # clipped to 0 because they're fully occluded. However, rescaling # in this manner is consistent with the previous implementation and # visually appears better than a "hard" clip. - intensity -= imin - intensity /= (imax - imin) + # intensity -= imin + # intensity /= (imax - imin) intensity = np.clip(intensity, 0, 1) return intensity \ No newline at end of file diff --git a/app/api/tiler.py b/app/api/tiler.py index a57007721..d04c7d1a1 100644 --- a/app/api/tiler.py +++ b/app/api/tiler.py @@ -463,9 +463,9 @@ def get(self, request, pk=None, project_pk=None, tile_type="", z="", x="", y="", if tile.data.shape[0] != 1: raise exceptions.ValidationError( _("Cannot compute hillshade of non-elevation raster (multiple bands found)")) - delta_scale = (maxzoom + ZOOM_EXTRA_LEVELS + 1 - z) * 4 + delta_scale = (maxzoom + ZOOM_EXTRA_LEVELS + 1 - z) ** 2 dx = src.dataset.meta["transform"][0] * delta_scale - dy = -src.dataset.meta["transform"][4] * delta_scale + dy = src.dataset.meta["transform"][4] * delta_scale ls = LightSource(azdeg=315, altdeg=45) # Remove elevation data from edge buffer tiles diff --git a/app/raster_utils.py b/app/raster_utils.py index d4fee27b9..310766ee8 100644 --- a/app/raster_utils.py +++ b/app/raster_utils.py @@ -233,9 +233,9 @@ def write_band(arr, dst, band_num): intensity = None if hillshade is not None and hillshade > 0: - delta_scale = (ZOOM_EXTRA_LEVELS + 1) * 4 + delta_scale = ZOOM_EXTRA_LEVELS ** 2 dx = src.meta["transform"][0] * delta_scale - dy = -src.meta["transform"][4] * delta_scale + dy = src.meta["transform"][4] * delta_scale ls = LightSource(azdeg=315, altdeg=45) intensity = ls.hillshade(arr[0], dx=dx, dy=dy, vert_exag=hillshade) intensity = intensity * 255.0