Moved image transpose to ASCOM Camera driver, improved obs.save_last_…

…image

pyscope/observatory/ascom_camera.py

@@ -1,5 +1,6 @@
 import logging
 from datetime import datetime as dt
+
 import numpy as np
 
 from .ascom_device import ASCOMDevice
@@ -20,6 +21,7 @@ def __init__(self, identifier, alpaca=False, device_number=0, protocol="http"):
         self._last_exposure_duration = None
         self._last_exposure_start_time = None
         self._image_data_type = None
+        self._DoTranspose = True
 
     def AbortExposure(self):
         logger.debug(f"ASCOMCamera.AbortExposure() called")
@@ -255,7 +257,9 @@ def ImageArray(self):
         if self._image_data_type is None:
             self.SetImageDataType()
         img_array = np.array(img_array, dtype=self._image_data_type)
-        return self._device.ImageArray
+        if self._DoTranspose:
+            img_array = np.transpose(img_array)
+        return img_array
 
     @property
     def ImageReady(self):
@@ -276,6 +280,9 @@ def LastExposureDuration(self):
     def LastExposureStartTime(self):
         logger.debug(f"ASCOMCamera.LastExposureStartTime property called")
         last_time = self._device.LastExposureStartTime
+        """ This code is needed to handle the case of the ASCOM ZWO driver
+        which returns an empty string instead of None if the camera does not
+        support the property """
         return (
             last_time
             if last_time != "" and last_time != None

pyscope/observatory/observatory.py

@@ -1168,11 +1168,14 @@ def save_last_image(
         if not self.camera.ImageReady:
             logger.exception("Image is not ready, cannot be saved")
             return False
+
+        # Read out the image array
+        img_array = self.camera.ImageArray
 
         if (
-            self.camera.ImageArray is None
-            or len(self.camera.ImageArray) == 0
-            or len(self.camera.ImageArray[0]) == 0
+            img_array is None
+            or len(img_array) == 0
+            or len(img_array) == 0
         ):
             logger.exception("Image array is empty, cannot be saved")
             return False
@@ -1182,9 +1185,9 @@ def save_last_image(
         hdr["SIMPLE"] = True
         hdr["BITPIX"] = (16, "8 unsigned int, 16 & 32 int, -32 & -64 real")
         hdr["NAXIS"] = (2, "number of axes")
-        hdr["NAXIS1"] = (len(self.camera.ImageArray), "fastest changing axis")
+        hdr["NAXIS1"] = (len(img_array), "fastest changing axis")
         hdr["NAXIS2"] = (
-            len(self.camera.ImageArray[0]),
+            len(img_array[0]),
             "next to fastest changing axis",
         )
         hdr["BSCALE"] = (1, "physical=BZERO + BSCALE*array_value")
@@ -1224,13 +1227,6 @@ def save_last_image(
             for hist in history:
                 hdr["HISTORY"] = hist
 
-        # By default, the ImageArray is 32 bit int, at least on my system
-        # of a ZWO 290MM Mini - we need to convert it to 16 bit unsigned int
-        img_array = np.array(self.camera.ImageArray).astype(np.uint16)
-        # Transpose the image array to match the FITS standard
-        # as well as the axis order defined above
-        img_array = np.transpose(img_array)
-
         hdu = fits.PrimaryHDU(img_array, header=hdr)
         hdu.writeto(filename, overwrite=overwrite)