add more metadata info (#159)

* add more metadata info

* add missing test

* update changes [skip-ci]

CHANGES.txt

@@ -4,6 +4,7 @@
 - added `rio_tiler.utils.has_mask_band` function
 - added `rio_tiler.utils.get_overview_level` to calculate the overview level needed for partial reading.
 - added type hints
+- added scale, offsets, colormap, datatype and colorinterp in reader.metadata output (#158)
 
 Breaking Changes:
 - removed python 2 support

rio_tiler/reader.py

@@ -413,8 +413,24 @@ def _get_descr(ix):
         for b in range(data.shape[0])
     }
 
+    other_meta = dict()
+    if src_dst.scales[0] and src_dst.offsets[0]:
+        other_meta.update(dict(scale=src_dst.scales[0]))
+        other_meta.update(dict(offset=src_dst.offsets[0]))
+
+    try:
+        cmap = src_dst.colormap(1)
+        other_meta.update(dict(colormap=cmap))
+    except ValueError:
+        pass
+
     return dict(
-        bounds=bounds, statistics=statistics, band_descriptions=band_descriptions
+        bounds=bounds,
+        statistics=statistics,
+        band_descriptions=band_descriptions,
+        dtype=src_dst.meta["dtype"],
+        colorinterp=[c.name for c in src_dst.colorinterp],
+        **other_meta,
     )
 
 

tests/test_reader.py

@@ -39,6 +39,7 @@
 
 COG_WEB_TILED = os.path.join(os.path.dirname(__file__), "fixtures", "web.tif")
 COG_SCALE = os.path.join(os.path.dirname(__file__), "fixtures", "cog_scale.tif")
+COG_CMAP = os.path.join(os.path.dirname(__file__), "fixtures", "cog_cmap.tif")
 
 
 @pytest.fixture(autouse=True)
@@ -450,3 +451,23 @@ def test_read_unscale():
             src_dst, [310000, 4100000], coord_crs=src_dst.crs, unscale=True
         )
         assert round(p[0], 3) == 1000.892
+
+
+def test_metadata():
+    """Should return correct metadata."""
+    with rasterio.open(COG_CMAP) as src_dst:
+        meta = reader.metadata(src_dst)
+        assert meta["dtype"] == "int8"
+        assert meta["colorinterp"] == ["palette"]
+        assert not meta.get("scale")
+        assert not meta.get("ofsset")
+        assert meta.get("colormap")
+
+    with rasterio.open(COG_SCALE) as src_dst:
+        meta = reader.metadata(src_dst)
+        assert meta["dtype"] == "int16"
+        assert meta["colorinterp"] == ["gray"]
+        assert meta["scale"] == 0.0001
+        assert meta["offset"] == 1000.0
+        assert meta["band_descriptions"] == [(1, "Green")]
+        assert not meta.get("colormap")