Create ImageReader subclasses

src/deepdisc/data_format/file_io.py

@@ -1,10 +1,6 @@
 import json
 from pathlib import Path
 
-import numpy as np
-from astropy.visualization import make_lupton_rgb
-
-
 def get_data_from_json(filename):
     """Open a JSON text file, and return encoded data as dictionary.
 
@@ -28,127 +24,3 @@ def get_data_from_json(filename):
     with open(filename, "r", encoding="utf-8") as f:
         data = json.load(f)
     return data
-
-
-class ImageReader:
-    """Class that will read images on the fly for the training/testing dataloaders"""
-
-    def __init__(self, reader, norm="raw", **scalekwargs):
-        """
-        Parameters
-        ----------
-        reader : function
-            This function should take a single key and return a single image as a numpy array
-            ex) give a filename or an index in an array
-        norm : str
-            A contrast scaling to apply before data augmentation, i.e. luptonizing or z-score scaling
-            Default = raw
-        **scalekwargs : key word args
-            Key word args for the contrast scaling function
-        """
-        self.reader = reader
-        self.scalekwargs = scalekwargs
-        self.scaling = ImageReader.norm_dict[norm]
-
-    def __call__(self, key):
-        """Read the image and apply scaling.
-
-        Parameters
-        ----------
-        key : str or int
-            The key indicating the image to read.
-
-        Returns
-        -------
-        im : numpy array
-            The image.
-        """
-        im = self.reader(key)
-        im_scale = self.scaling(im, **self.scalekwargs)
-        return im_scale
-
-    def raw(im):
-        """Apply raw image scaling (no scaling done).
-
-        Parameters
-        ----------
-        im : numpy array
-            The image.
-
-        Returns
-        -------
-        numpy array
-            The image with pixels as float32.
-        """
-        return im.astype(np.float32)
-
-    def lupton(im, bandlist=[2, 1, 0], stretch=0.5, Q=10, m=0):
-        """Apply Lupton scaling to the image and return the scaled image.
-
-        Parameters
-        ----------
-        im : np array
-            The image being scaled
-        bandlist : list[int]
-            Which bands to use for lupton scaling (must be 3)
-        stretch : float
-            lupton stretch parameter
-        Q : float
-            lupton Q parameter
-        m: float
-            lupton minimum parameter
-
-        Returns
-        -------
-        image : numpy array
-            The 3-channel image after lupton scaling using astropy make_lupton_rgb
-        """
-        assert np.array(im.shape).argmin() == 2 and len(bandlist) == 3
-        b1 = im[:, :, bandlist[0]]
-        b2 = im[:, :, bandlist[1]]
-        b3 = im[:, :, bandlist[2]]
-
-        image = make_lupton_rgb(b1, b2, b3, minimum=m, stretch=stretch, Q=Q)
-        return image
-
-    def zscore(im, A=1):
-        """Apply z-score scaling to the image and return the scaled image.
-
-        Parameters
-        ----------
-        im : np array
-            The image being scaled
-        A : float
-            A multiplicative scaling factor applied to each band
-
-        Returns
-        -------
-        image : numpy array
-            The image after z-score scaling (subtract mean and divide by std deviation)
-        """
-        I = np.mean(im, axis=-1)
-        Imean = np.nanmean(I)
-        Isigma = np.nanstd(I)
-
-        for i in range(im.shape[-1]):
-            image[:, :, i] = A * (im[:, :, i] - Imean - m) / Isigma
-
-        return image
-
-    #This dict is created to map an input string to a scaling function
-    norm_dict = {"raw": raw, "lupton": lupton}
-
-    @classmethod
-    def add_scaling(cls, name, func):
-        """Add a custom contrast scaling function
-
-        ex)
-        def sqrt(image):
-            image[:,:,0] = np.sqrt(image[:,:,0])
-            image[:,:,1] = np.sqrt(image[:,:,1])
-            image[:,:,2] = np.sqrt(image[:,:,2])
-            return image
-
-        ImageReader.add_scaling('sqrt',sqrt)
-        """
-        cls.norm_dict[name] = func

src/deepdisc/data_format/image_readers.py

@@ -0,0 +1,210 @@
+import abc
+import os
+import numpy as np
+
+from astropy.io import fits
+from astropy.visualization import make_lupton_rgb
+
+class ImageReader(abc.ABC):
+    """Base class that will read images on the fly for the training/testing dataloaders
+
+    To implement an image reader for a new class, the derived class needs to have an
+    __init__() function that calls super().__init__(*args, **kwargs)
+    and a custom version of _read_image().
+    """
+
+    def __init__(self, norm="raw", *args, **kwargs):
+        """
+        Parameters
+        ----------
+        norm : str (optional)
+            A contrast scaling to apply before data augmentation, i.e. luptonizing or z-score scaling
+            Default = raw
+        **kwargs : key word args
+            Key word args for the contrast scaling function
+        """
+        self.scaling = ImageReader.norm_dict[norm]
+        self.scalekwargs = kwargs
+
+    @abc.abstractmethod
+    def _read_image(self, key):
+        """Read the image. No-op implementation.
+
+        Parameters
+        ----------
+        key : str or int
+            The key indicating the image to read.
+
+        Returns
+        -------
+        im : numpy array
+            The image.
+        """
+        pass
+
+    def __call__(self, key):
+        """Read the image and apply scaling.
+
+        Parameters
+        ----------
+        key : str or int
+            The key indicating the image to read.
+
+        Returns
+        -------
+        im : numpy array
+            The image.
+        """
+        im = self._read_image(key)
+        im_scale = self.scaling(im, **self.scalekwargs)
+        return im_scale
+
+    def raw(im):
+        """Apply raw image scaling (no scaling done).
+
+        Parameters
+        ----------
+        im : numpy array
+            The image.
+
+        Returns
+        -------
+        numpy array
+            The image with pixels as float32.
+        """
+        return im.astype(np.float32)
+
+    def lupton(im, bandlist=[2, 1, 0], stretch=0.5, Q=10, m=0):
+        """Apply Lupton scaling to the image and return the scaled image.
+
+        Parameters
+        ----------
+        im : np array
+            The image being scaled
+        bandlist : list[int]
+            Which bands to use for lupton scaling (must be 3)
+        stretch : float
+            lupton stretch parameter
+        Q : float
+            lupton Q parameter
+        m: float
+            lupton minimum parameter
+
+        Returns
+        -------
+        image : numpy array
+            The 3-channel image after lupton scaling using astropy make_lupton_rgb
+        """
+        assert np.array(im.shape).argmin() == 2 and len(bandlist) == 3
+        b1 = im[:, :, bandlist[0]]
+        b2 = im[:, :, bandlist[1]]
+        b3 = im[:, :, bandlist[2]]
+
+        image = make_lupton_rgb(b1, b2, b3, minimum=m, stretch=stretch, Q=Q)
+        return image
+
+    def zscore(im, A=1):
+        """Apply z-score scaling to the image and return the scaled image.
+
+        Parameters
+        ----------
+        im : np array
+            The image being scaled
+        A : float
+            A multiplicative scaling factor applied to each band
+
+        Returns
+        -------
+        image : numpy array
+            The image after z-score scaling (subtract mean and divide by std deviation)
+        """
+        I = np.mean(im, axis=-1)
+        Imean = np.nanmean(I)
+        Isigma = np.nanstd(I)
+
+        for i in range(im.shape[-1]):
+            image[:, :, i] = A * (im[:, :, i] - Imean - m) / Isigma
+
+        return image
+
+    #This dict is created to map an input string to a scaling function
+    norm_dict = {"raw": raw, "lupton": lupton}
+
+    @classmethod
+    def add_scaling(cls, name, func):
+        """Add a custom contrast scaling function
+
+        ex)
+        def sqrt(image):
+            image[:,:,0] = np.sqrt(image[:,:,0])
+            image[:,:,1] = np.sqrt(image[:,:,1])
+            image[:,:,2] = np.sqrt(image[:,:,2])
+            return image
+
+        ImageReader.add_scaling('sqrt',sqrt)
+        """
+        cls.norm_dict[name] = func
+
+
+class DC2ImageReader(ImageReader):
+    """An ImageReader for DC2 image files."""
+
+    def __init__(self, *args, **kwargs):
+        # Pass arguments to the parent function.
+        super().__init__(*args, **kwargs)
+
+    def _read_image(self, filename):
+        """Read the image.
+
+        Parameters
+        ----------
+        filename : str
+            The filename indicating the image to read.
+
+        Returns
+        -------
+        im : numpy array
+            The image.
+        """
+        file = filename.split("/")[-1].split(".")[0]
+        base = os.path.dirname(filename)
+        fn = os.path.join(base, file) + ".npy"
+        image = np.load(fn)
+        image = np.transpose(image, axes=(1, 2, 0)).astype(np.float32)
+        return image
+
+
+class HSCImageReader(ImageReader):
+    """An ImageReader for HSC image files."""
+
+    def __init__(self, *args, **kwargs):
+        # Pass arguments to the parent function.
+        super().__init__(*args, **kwargs)
+
+    def _read_image(self, filenames):
+        """Read the image.
+
+        Parameters
+        ----------
+        filenames : list
+            A length 3 list of filenames for the I, R, and G images.
+
+        Returns
+        -------
+        im : numpy array
+            The image.
+        """
+        if len(filenames) != 3:
+            raise ValueError("Incorrect number of filenames passed.")
+
+        g = fits.getdata(os.path.join(filenames[0]), memmap=False)
+        length, width = g.shape
+        image = np.empty([length, width, 3])
+        r = fits.getdata(os.path.join(filenames[1]), memmap=False)
+        i = fits.getdata(os.path.join(filenames[2]), memmap=False)
+
+        image[:, :, 0] = i
+        image[:, :, 1] = r
+        image[:, :, 2] = g
+        return image
+

src/deepdisc/inference/predictors.py

@@ -30,8 +30,8 @@ def get_predictions(dataset_dict, imreader, key_mapper, predictor):
     ----------
     dataset_dict : dictionary
         The dictionary metadata for a single image
-    imreader: ImageReader class
-        The ImageReader used to load in images
+    imreader: ImageReader object
+        An object derived from ImageReader base class to read the images.
     key_mapper: function
         The key_mapper should take a dataset_dict as input and return the key used by imreader
     predictor: AstroPredictor