API

The API works with Sentinel-2 satellite images. It has two endpoints:

• /attributes: Returns the attributes of the image

  • width: The width of the raster in pixels.
  • height: The height of the raster in pixels.
  • bands: The number of bands in the raster. Each band represents a different channel of data, such as red, green, and blue.
  • crs: The coordinate reference system (CRS) of the raster. The CRS defines how the raster is projected onto the Earth.
  • bbox: The bounding box of the raster. The bounding box defines the minimum and maximum latitude and longitude values of the raster.
  • driver: The driver that was used to create the raster file. The driver defines the format of the raster file.
  • dtype: The data type of the raster image. The data type defines the type of data that is stored in each pixel of the image.
  • transform: The transform of the raster image. The transform defines how the raster image is georeferenced.
  • nodata: The nodata value of the raster image. The nodata value defines which pixels are not valid data.

To retrieve all attributes, you can use the following snippet, which uses the rasterio library to read the image and retrieve the metadata (alternatively, you can use dataset.attr):

import rasterio
 
with rasterio.open("S2L2A_2022-06-09.tiff") as dataset:
    metadata = dataset.meta
 
print(metadata)

• /thumbnail: Returns a thumbnail of the image at a given resolution (e.g. 200x200)

The application uses Rasterio to read the image and Pillow to create the thumbnail.

Tech Stack

1. Python: The programming language used to write the code.

2. FastAPI: A modern, fast (high-performance), web framework for building APIs with Python 3.6+ based on standard Python type hints.

3. Rasterio: A Python library that allows for easy reading and writing of geospatial raster data (like GeoTIFF files).

4. PIL (Python Imaging Library): A Python library used for opening, manipulating, and saving many different image file formats.

5. Matplotlib: A plotting library for the Python programming language and its numerical mathematics extension NumPy.

6. Uvicorn: An ASGI server that runs asynchronous Python web code in a single process.

7. io: A Python module that provides the Python interfaces to stream handling. The builtin open function is defined in this module.

8. typing: A Python module that provides runtime support for type hints as specified by PEP 484, PEP 526, PEP 544, PEP 586, PEP 589, and PEP 560.