Add plot method and data.py to Sentinel Dataset (#416)

* add plot method and data.py

* Adding normalization for plot

Co-authored-by: Caleb Robinson <calebrob6@gmail.com>

tests/data/sentinel2/data.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+import os
+import random
+
+import numpy as np
+import rasterio
+
+SIZE = 32
+
+np.random.seed(0)
+random.seed(0)
+
+filenames = [
+    "T41XNE_20200829T083611_B01_60m.tif",
+    "T41XNE_20200829T083611_B02_10m.tif",
+    "T41XNE_20200829T083611_B03_10m.tif",
+    "T41XNE_20200829T083611_B04_10m.tif",
+    "T41XNE_20200829T083611_B05_20m.tif",
+    "T41XNE_20200829T083611_B06_20m.tif",
+    "T41XNE_20200829T083611_B07_20m.tif",
+    "T41XNE_20200829T083611_B08_10m.tif",
+    "T41XNE_20200829T083611_B8A_20m.tif",
+    "T41XNE_20200829T083611_B09_60m.tif",
+    "T41XNE_20200829T083611_B11_20m.tif",
+]
+
+
+def create_file(path: str, dtype: str, num_channels: int) -> None:
+    profile = {}
+    profile["driver"] = "GTiff"
+    profile["dtype"] = dtype
+    profile["count"] = num_channels
+    profile["crs"] = "epsg:4326"
+    profile["transform"] = rasterio.transform.from_bounds(0, 0, 1, 1, 1, 1)
+    profile["height"] = SIZE
+    profile["width"] = SIZE
+    profile["compress"] = "lzw"
+    profile["predictor"] = 2
+
+    if "float" in profile["dtype"]:
+        Z = np.random.randn(SIZE, SIZE).astype(profile["dtype"])
+    else:
+        Z = np.random.randint(
+            np.iinfo(profile["dtype"]).max, size=(SIZE, SIZE), dtype=profile["dtype"]
+        )
+
+    src = rasterio.open(path, "w", **profile)
+    for i in range(1, profile["count"] + 1):
+        src.write(Z, i)
+
+
+if __name__ == "__main__":
+    for f in filenames:
+        if os.path.exists(f):
+            os.remove(f)
+
+        create_file(path=f, dtype="int32", num_channels=1)

tests/datasets/test_sentinel.py

@@ -53,6 +53,19 @@ def test_no_data(self, tmp_path: Path) -> None:
         with pytest.raises(FileNotFoundError, match="No Sentinel2 data was found in "):
             Sentinel2(str(tmp_path))
 
+    def test_plot(self, dataset: Sentinel2) -> None:
+        x = dataset[dataset.bounds]
+        dataset.plot(x, suptitle="Test")
+
+    def test_plot_wrong_bands(self, dataset: Sentinel2) -> None:
+        bands = ("B01",)
+        ds = Sentinel2(root=dataset.root, bands=bands)
+        x = dataset[dataset.bounds]
+        with pytest.raises(
+            ValueError, match="Dataset doesn't contain some of the RGB bands"
+        ):
+            ds.plot(x)
+
     def test_invalid_query(self, dataset: Sentinel2) -> None:
         query = BoundingBox(0, 0, 0, 0, 0, 0)
         with pytest.raises(

torchgeo/datasets/sentinel.py

@@ -5,7 +5,10 @@
 
 from typing import Any, Callable, Dict, Optional, Sequence
 
+import matplotlib.pyplot as plt
+import torch
 from rasterio.crs import CRS
+from torch import Tensor
 
 from .geo import RasterDataset
 
@@ -66,7 +69,7 @@ class Sentinel2(Sentinel):
         "B11",
         "B12",
     ]
-    rgb_bands = ["B04", "B03", "B02"]
+    RGB_BANDS = ["B04", "B03", "B02"]
 
     separate_files = True
 
@@ -98,3 +101,47 @@ def __init__(
         self.bands = bands if bands else self.all_bands
 
         super().__init__(root, crs, res, transforms, cache)
+
+    def plot(  # type: ignore[override]
+        self,
+        sample: Dict[str, Tensor],
+        show_titles: bool = True,
+        suptitle: Optional[str] = None,
+    ) -> plt.Figure:
+        """Plot a sample from the dataset.
+
+        Args:
+            sample: a sample returned by :meth:`RasterDataset.__getitem__`
+            show_titles: flag indicating whether to show titles above each panel
+            suptitle: optional string to use as a suptitle
+
+        Returns:
+            a matplotlib Figure with the rendered sample
+
+        Raises:
+            ValueError: if the RGB bands are not included in ``self.bands``
+
+        .. versionadded:: 0.3
+        """
+        rgb_indices = []
+        for band in self.RGB_BANDS:
+            if band in self.bands:
+                rgb_indices.append(self.bands.index(band))
+            else:
+                raise ValueError("Dataset doesn't contain some of the RGB bands")
+
+        image = sample["image"][rgb_indices].permute(1, 2, 0)
+        image = torch.clamp(image / 3000, min=0, max=1)  # type: ignore[attr-defined]
+
+        fig, ax = plt.subplots(1, 1, figsize=(4, 4))
+
+        ax.imshow(image)
+        ax.axis("off")
+
+        if show_titles:
+            ax.set_title("Image")
+
+        if suptitle is not None:
+            plt.suptitle(suptitle)
+
+        return fig