Merge pull request #37 from rok4/feature/rasterset

Feature/rasterset

Author: Dolite

src/rok4/Raster.py

@@ -1,18 +1,20 @@
-"""Provide functions to read information on raster data from file path or object path
+"""Provide functions to read information on raster data
 
 The module contains the following class :
 
-    - 'Raster' - Structure describing raster data.
-
+    - Raster - Structure describing raster data.
+    - RasterSet - Structure describing a set of raster data.
 """
 
+import copy
+import json
 import re
 from enum import Enum
+from typing import Tuple, Dict
 
 from osgeo import ogr, gdal
-from typing import Tuple
 
-from rok4.Storage import exists, get_osgeo_path
+from rok4.Storage import exists, get_osgeo_path, put_data_str
 from rok4.Utils import ColorFormat, compute_bbox,compute_format
 
 # Enable GDAL/OGR exceptions
@@ -23,12 +25,18 @@ class Raster:
     """A structure describing raster data
 
     Attributes :
-        path (str): path to the file/object (ex: file:///path/to/image.tif or s3://bucket/path/to/image.tif)
-        bbox (Tuple[float, float, float, float]): bounding rectange in the data projection
+        path (str): path to the file/object (ex:
+          file:///path/to/image.tif or s3://bucket/path/to/image.tif)
+        bbox (Tuple[float, float, float, float]): bounding rectange
+          in the data projection
         bands (int): number of color bands (or channels)
-        format (ColorFormat): numeric variable format for color values. Bit depth, as bits per channel, can be derived from it.
-        mask (str): path to the associated mask file or object, if any, or None (same path as the image, but with a ".msk" extension and TIFF format. ex: file:///path/to/image.msk or s3://bucket/path/to/image.msk)
-        dimensions (Tuple[int, int]): image width and height expressed in pixels
+        format (ColorFormat): numeric variable format for color values.
+          Bit depth, as bits per channel, can be derived from it.
+        mask (str): path to the associated mask file or object, if any,
+          or None (same path as the image, but with a ".msk" extension
+          and TIFF format. ex:
+          file:///path/to/image.msk or s3://bucket/path/to/image.msk)
+        dimensions (Tuple[int, int]): image width and height, in pixels
     """
 
     def __init__(self) -> None:
@@ -40,7 +48,7 @@ def __init__(self) -> None:
         self.path = None
 
     @classmethod
-    def from_file(cls, path: str) -> 'Raster':
+    def from_file(cls, path: str) -> "Raster":
         """Creates a Raster object from an image
 
         Args:
@@ -53,7 +61,9 @@ def from_file(cls, path: str) -> 'Raster':
                 from rok4.Raster import Raster
 
                 try:
-                    raster = Raster.from_file("file:///data/images/SC1000_TIFF_LAMB93_FXX/SC1000_0040_6150_L93.tif")
+                    raster = Raster.from_file(
+                        "file:///data/SC1000/0040_6150_L93.tif"
+                    )
 
                 except Exception as e:
                     print(f"Cannot load information from image : {e}")
@@ -65,7 +75,6 @@ def from_file(cls, path: str) -> 'Raster':
         Returns:
             Raster: a Raster instance
         """
-
         if not exists(path):
             raise Exception(f"No file or object found at path '{path}'.")
 
@@ -76,15 +85,16 @@ def from_file(cls, path: str) -> 'Raster':
         image_datasource = gdal.Open(work_image_path)
         self.path = path
 
-        path_pattern = re.compile('(/[^/]+?)[.][a-zA-Z0-9_-]+$')
-        mask_path = path_pattern.sub('\\1.msk', path)
+        path_pattern = re.compile("(/[^/]+?)[.][a-zA-Z0-9_-]+$")
+        mask_path = path_pattern.sub("\\1.msk", path)
 
         if exists(mask_path):
             work_mask_path = get_osgeo_path(mask_path)
             mask_driver = gdal.IdentifyDriver(work_mask_path).ShortName
             if 'GTiff' != mask_driver:
-                raise Exception(f"Mask file '{mask_path}' is not a TIFF image. (GDAL driver : '{mask_driver}'")
-
+                message = (f"Mask file '{mask_path}' is not a TIFF image."
+                           + f" (GDAL driver : '{mask_driver}'")
+                raise Exception(message)
             self.mask = mask_path
         else:
             self.mask = None
@@ -97,36 +107,55 @@ def from_file(cls, path: str) -> 'Raster':
         return self
 
     @classmethod
-    def from_parameters(cls, path: str, bands: int, bbox: Tuple[float, float, float, float], dimensions: Tuple[int, int], format: ColorFormat, mask: str = None) -> 'Raster':
+    def from_parameters(
+            cls, path: str, bands: int, bbox: Tuple[float, float, float, float],
+            dimensions: Tuple[int, int], format: ColorFormat, mask: str = None) -> "Raster":
         """Creates a Raster object from parameters
 
         Args:
-            path (str): path to the file/object (ex: file:///path/to/image.tif or s3://bucket/path/to/image.tif)
+            path (str): path to the file/object (ex:
+              file:///path/to/image.tif or s3://bucket/image.tif)
             bands (int): number of color bands (or channels)
-            bbox (Tuple[float, float, float, float]): bounding rectange in the data projection
-            dimensions (Tuple[int, int]): image width and height expressed in pixels
-            format (ColorFormat): numeric variable format for color values. Bit depth, as bits per channel, can be derived from it.
-            mask (str, optionnal): path to the associated mask file or object, if any, or None (same path as the image, but with a ".msk" extension and TIFF format. ex: file:///path/to/image.msk or s3://bucket/path/to/image.msk)
+            bbox (Tuple[float, float, float, float]): bounding rectange
+              in the data projection
+            dimensions (Tuple[int, int]): image width and height
+              expressed in pixels
+            format (ColorFormat): numeric format for color values.
+              Bit depth, as bits per channel, can be derived from it.
+            mask (str, optionnal): path to the associated mask, if any,
+              or None (same path as the image, but with a
+              ".msk" extension and TIFF format. ex:
+              file:///path/to/image.msk or s3://bucket/image.msk)
 
         Examples:
 
-            Loading informations from parameters, related to a TIFF main image coupled to a TIFF mask image
+            Loading informations from parameters, related to
+              a TIFF main image coupled to a TIFF mask image
 
                 from rok4.Raster import Raster
 
                 try:
-                    raster = Raster.from_parameters(path="file:///data/images/SC1000_TIFF_LAMB93_FXX/SC1000_0040_6150_L93.tif", mask="file:///data/images/SC1000_TIFF_LAMB93_FXX/SC1000_0040_6150_L93.msk", bands=3, format=ColorFormat.UINT8, dimensions=(2000, 2000), bbox=(40000.000, 5950000.000, 240000.000, 6150000.000))
+                    raster = Raster.from_parameters(
+                      path="file:///data/SC1000/_0040_6150_L93.tif",
+                      mask="file:///data/SC1000/0040_6150_L93.msk",
+                      bands=3,
+                      format=ColorFormat.UINT8,
+                      dimensions=(2000, 2000),
+                      bbox=(40000.000, 5950000.000,
+                            240000.000, 6150000.000)
+                    )
 
                 except Exception as e:
-                    print(f"Cannot load information from parameters : {e}")
+                    print(
+                      f"Cannot load information from parameters : {e}"
+                    )
 
         Raises:
             KeyError: a mandatory argument is missing
 
         Returns:
             Raster: a Raster instance
         """
-
         self = cls()
 
         self.path = path
@@ -135,5 +164,192 @@ def from_parameters(cls, path: str, bands: int, bbox: Tuple[float, float, float,
         self.dimensions = dimensions
         self.format = format
         self.mask = mask
+        return self
+
+
+class RasterSet:
+    """A structure describing a set of raster data
+
+    Attributes :
+        raster_list (List[Raster]): List of Raster instances in the set
+        colors (List[Dict]): List of color properties for each raster
+              instance. Contains only one element if
+              the set is homogenous.
+            Element properties:
+                bands (int): number of color bands (or channels)
+                format (ColorFormat): numeric variable format for
+                  color values. Bit depth, as bits per channel,
+                  can be derived from it.
+        srs (str): Name of the set's spatial reference system
+        bbox (Tuple[float, float, float, float]): bounding rectange
+          in the data projection, enclosing the whole set
+    """
+
+    def __init__(self) -> None:
+        self.bbox = (None, None, None, None)
+        self.colors = []
+        self.raster_list = []
+        self.srs = None
+
+    @classmethod
+    def from_list(cls, path: str, srs: str) -> "RasterSet":
+        """Instanciate a RasterSet from an images list path and a srs
+
+        Args:
+            path (str): path to the images list file or object
+              (each line in this list contains the path to
+              an image file or object in the set)
+
+        Examples:
+
+            Loading informations from a file stored list
+
+                from rok4.Raster import RasterSet
+
+                try:
+                    raster_set = RasterSet.from_list(
+                      path="file:///data/SC1000.list",
+                      srs="EPSG:3857"
+                    )
+
+                except Exception as e:
+                    print(
+                      f"Cannot load information from list file : {e}"
+                    )
+
+        Raises:
+            RuntimeError: raised by OGR/GDAL if anything goes wrong
+            NotImplementedError: Storage type not handled
+
+        Returns:
+            RasterSet: a RasterSet instance
+        """
+        self = cls()
+        self.srs = srs
+
+        local_list_path = get_osgeo_path(path)
+        image_list = []
+        with open(file=local_list_path, mode="r") as list_file:
+            for line in list_file:
+                image_path = line.strip(" \t\n\r")
+                image_list.append(image_path)
+
+        temp_bbox = [None, None, None, None]
+        for image_path in image_list:
+            raster = Raster.from_file(image_path)
+            self.raster_list.append(raster)
+            if temp_bbox == [None, None, None, None]:
+                for i in range(0, 4, 1):
+                    temp_bbox[i] = raster.bbox[i]
+            else:
+                if temp_bbox[0] > raster.bbox[0]:
+                    temp_bbox[0] = raster.bbox[0]
+                if temp_bbox[1] > raster.bbox[1]:
+                    temp_bbox[1] = raster.bbox[1]
+                if temp_bbox[2] < raster.bbox[2]:
+                    temp_bbox[2] = raster.bbox[2]
+                if temp_bbox[3] < raster.bbox[3]:
+                    temp_bbox[3] = raster.bbox[3]
+            color_dict = {"bands": raster.bands, "format": raster.format}
+            if color_dict not in self.colors:
+                self.colors.append(color_dict)
+        self.bbox = tuple(temp_bbox)
+        return self
+
+    @classmethod
+    def from_descriptor(cls, path: str) -> "RasterSet":
+        """Creates a RasterSet object from a descriptor file or object
+
+        Args:
+            path (str): path to the descriptor file or object
+
+        Examples:
+
+            Loading informations from a file stored descriptor
+
+                from rok4.Raster import RasterSet
+
+                try:
+                    raster_set = RasterSet.from_descriptor(
+                      "file:///data/images/descriptor.json"
+                    )
+
+                except Exception as e:
+                    message = ("Cannot load information from "
+                              + f"descriptor file : {e}")
+                    print(message)
 
+        Raises:
+            RuntimeError: raised by OGR/GDAL if anything goes wrong
+            NotImplementedError: Storage type not handled
+
+        Returns:
+            RasterSet: a RasterSet instance
+        """
+        self = cls()
+        descriptor_path = get_osgeo_path(path)
+        with open(file=descriptor_path, mode="r") as file_handle:
+            raw_content = file_handle.read()
+        serialization = json.loads(raw_content)
+        self.srs = serialization["srs"]
+        self.raster_list = []
+        for raster_dict in serialization["raster_list"]:
+            parameters = copy.deepcopy(raster_dict)
+            parameters["bbox"] = tuple(raster_dict["bbox"])
+            parameters["dimensions"] = tuple(raster_dict["dimensions"])
+            parameters["format"] = ColorFormat[ raster_dict["format"] ]
+            self.raster_list.append(Raster.from_parameters(**parameters))
+        self.bbox = tuple(serialization["bbox"])
+        self.colors = []
+        for color_dict in serialization["colors"]:
+            color_item = copy.deepcopy(color_dict)
+            color_item["format"] = ColorFormat[ color_dict["format"] ]
+            self.colors.append(color_item)
         return self
+
+    @property
+    def serializable(self) -> Dict:
+        """Get the dict version of the raster set, descriptor compliant
+
+        Returns:
+            Dict: descriptor structured object description
+        """
+        serialization = {
+            "bbox": list(self.bbox),
+            "srs": self.srs,
+            "colors": [],
+            "raster_list" : []
+        }
+        for color in self.colors:
+            color_serial = {
+                "bands": color["bands"],
+                "format": color["format"].name
+            }
+            serialization["colors"].append(color_serial)
+        for raster in self.raster_list:
+            raster_dict = {
+                "path": raster.path,
+                "dimensions": list(raster.dimensions),
+                "bbox": list(raster.bbox),
+                "bands": raster.bands,
+                "format": raster.format.name
+            }
+            if raster.mask is not None:
+                raster_dict["mask"] = raster.mask
+            serialization["raster_list"].append(raster_dict)
+        return serialization
+
+    def write_descriptor(self, path: str = None) -> None:
+        """Print raster set's descriptor as JSON
+
+        Args:
+            path (str, optional): Complete path (file or object)
+              where to print the raster set's JSON. Defaults to None,
+              JSON is printed to standard output.
+        """
+        content = json.dumps(self.serializable, sort_keys=True)
+        if path is None:
+            print(content)
+        else:
+            put_data_str(content, path)
+