From 83acc2e1dc3d4abd4e0392e401802137a4402b1b Mon Sep 17 00:00:00 2001
From: David de Meij <daviddemeij@gmail.com>
Date: Tue, 15 Mar 2022 16:26:01 +0100
Subject: [PATCH] Return False, None if the mask for a certain tile contains no
 valid pixels.

---
 s2p/initialization.py | 2 ++
 s2p/masking.py        | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/s2p/initialization.py b/s2p/initialization.py
index 7e147294..fab72d95 100644
--- a/s2p/initialization.py
+++ b/s2p/initialization.py
@@ -308,6 +308,8 @@ def is_this_tile_useful(x, y, w, h, images_sizes):
     wat_msk = cfg['images'][0]['wat']
     mask = masking.image_tile_mask(x, y, w, h, roi_msk, cld_msk, wat_msk,
                                    images_sizes[0], cfg['border_margin'])
+    if not mask.any():
+        return False, None
     return True, mask
 
 
diff --git a/s2p/masking.py b/s2p/masking.py
index 46cc0943..414d7e72 100644
--- a/s2p/masking.py
+++ b/s2p/masking.py
@@ -69,6 +69,8 @@ def image_tile_mask(x, y, w, h, roi_gml=None, cld_gml=None, raster_mask=None,
         with rasterio.open(raster_mask, 'r') as f:
             mask = np.logical_and(mask, f.read(window=((y, y+h), (x, x+w)),
                                                boundless=True).squeeze())
+        if not mask.any():
+            return mask
 
     # image borders mask
     if img_shape is not None: