Landsat: add plot method

[adamjstewart]

We removed the RasterDataset.plot method in #476. Landsat was the only remaining RasterDataset that didn't have a replacement plot method. Added it so we don't have to explain why Landsat used to have a plot method but no longer does.

Also cleaned up some typing and documentation mistakes. RasterDataset.__getitem__ returns Dict[str, Any], not Dict[str, Tensor]. Plot methods weren't added in 0.3 since they existed (albeit in the base class) in 0.2. They were changed because they now have completely different inputs.

Example image from Novaya Zemlya, Russia:

[calebrob6]

How are you generating that actually? I'm getting problems:

from torchgeo.datasets import Landsat8
from torchgeo.samplers import RandomGeoSampler
import numpy as np
import matplotlib.pyplot as plt

ds = Landsat8(root="tmp/", bands=Landsat8.all_bands)
sampler = RandomGeoSampler(ds, size=50, length=1)
bb = next(iter(sampler))
ds[bb]

Is giving me the following error:

---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
/tmp/ipykernel_32350/2392223127.py in <module>
----> 1 ds[bb]

~/code/torchgeo/torchgeo/datasets/geo.py in __getitem__(self, query)
    417                             end = match.end("resolution")
    418                             filename = filename[:start] + "*" + filename[end:]
--> 419                     filepath = glob.glob(os.path.join(directory, filename))[0]
    420                     band_filepaths.append(filepath)
    421                 data_list.append(self._merge_files(band_filepaths, query))

IndexError: list index out of range

Where:

> ls tmp
LC08_L2SP_013033_20190830_20200826_02_T1_SR_B1.TIF
LC08_L2SP_013033_20190830_20200826_02_T1_SR_B2.TIF
LC08_L2SP_013033_20190830_20200826_02_T1_SR_B3.TIF
LC08_L2SP_013033_20190830_20200826_02_T1_SR_B4.TIF
LC08_L2SP_013033_20190830_20200826_02_T1_SR_B5.TIF
LC08_L2SP_013033_20190830_20200826_02_T1_SR_B6.TIF
LC08_L2SP_013033_20190830_20200826_02_T1_SR_B7.TIF

[calebrob6]

Ahhh nvrmnd I didn't have all the bands downloaded but it was defaulting to all bands.

[calebrob6]

Stretching to full range is okay. When the image patch doesn't have a wide range it looks overexposed, but for most cases it will be fine!

E.g. water only patch

What happens when you divide by constant and clip: