Read reference images externally

Read reference images externally, like the input data.

satpy/tests/behave/features/steps/image_comparison.py

@@ -1,74 +1,96 @@
+# Copyright (c) 2024 Satpy developers
+#
+# This file is part of satpy.
+#
+# satpy is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# satpy.  If not, see <http://www.gnu.org/licenses/>.
+"""Image comparison tests."""
+
 import os
 import warnings
+from datetime import datetime
 from glob import glob
-from PIL import Image
+
 import cv2
 import dask
 import numpy as np
-from behave import given, when, then
-from satpy import Scene
-from datetime import datetime
 import pytz
+from behave import given, then, when
+
+from satpy import Scene
 
 ext_data_path = "/app/ext_data"
 #ext_data_path = "/home/bildabgleich/pytroll-image-comparison-tests/data"
 threshold = 2000
 
-# Define a before_all hook to create the timestamp and test results directory
 def before_all(context):
-    berlin_time = datetime.now(pytz.timezone('Europe/Berlin'))
+    """Define a before_all hook to create the timestamp and test results directory."""
+    berlin_time = datetime.now(pytz.timezone("Europe/Berlin"))
     context.timestamp = berlin_time.strftime("%Y-%m-%d-%H-%M-%S")
     context.test_results_dir = f"{ext_data_path}/test_results/image_comparison/{context.timestamp}"
-    os.makedirs(os.path.join(context.test_results_dir, 'generated'), exist_ok=True)
-    os.makedirs(os.path.join(context.test_results_dir, 'difference'), exist_ok=True)
+    os.makedirs(os.path.join(context.test_results_dir, "generated"), exist_ok=True)
+    os.makedirs(os.path.join(context.test_results_dir, "difference"), exist_ok=True)
 
     # Write the timestamp to test_results.txt
-    results_file = os.path.join(context.test_results_dir, 'test_results.txt')
-    with open(results_file, 'a') as f:
+    results_file = os.path.join(context.test_results_dir, "test_results.txt")
+    with open(results_file, "a") as f:
         f.write(f"Test executed at {context.timestamp}.\n\n")
 
-# Register the before_all hook
 def setup_hooks():
+    """Register the before_all hook."""
     from behave import use_fixture
     from behave.runner import Context
 
     use_fixture(before_all, Context)
 
 setup_hooks()
-@given('I have a {composite} reference image file from {satellite}')
+@given("I have a {composite} reference image file from {satellite}")
 def step_given_reference_image(context, composite, satellite):
+    """Prepare a reference image."""
     reference_image = f"reference_image_{satellite}_{composite}.png"
-    context.reference_image = cv2.imread(f"./features/data/reference/{reference_image}")
+    #context.reference_image = cv2.imread(f"./features/data/reference/{reference_image}")
+    context.reference_image = cv2.imread(f"{ext_data_path}/reference_images/{reference_image}")
     context.reference_different_image = cv2.imread(f"./features/data/reference_different/{reference_image}")
     context.satellite = satellite
     context.composite = composite
 
 
-@when('I generate a new {composite} image file from {satellite}')
+@when("I generate a new {composite} image file from {satellite}")
 def step_when_generate_image(context, composite, satellite):
-    os.environ['OMP_NUM_THREADS'] = os.environ['MKL_NUM_THREADS'] = '2'
-    os.environ['PYTROLL_CHUNK_SIZE'] = '1024'
-    warnings.simplefilter('ignore')
-    dask.config.set(scheduler='threads', num_workers=4)
+    """Generate test images."""
+    os.environ["OMP_NUM_THREADS"] = os.environ["MKL_NUM_THREADS"] = "2"
+    os.environ["PYTROLL_CHUNK_SIZE"] = "1024"
+    warnings.simplefilter("ignore")
+    dask.config.set(scheduler="threads", num_workers=4)
 
     # Get the list of satellite files to open
-    filenames = glob(f'{ext_data_path}/satellite_data/{satellite}/*.nc')
+    filenames = glob(f"{ext_data_path}/satellite_data/{satellite}/*.nc")
 
-    scn = Scene(reader='abi_l1b', filenames=filenames)
+    scn = Scene(reader="abi_l1b", filenames=filenames)
 
     scn.load([composite])
 
     # Save the generated image in the generated folder
-    generated_image_path = os.path.join(context.test_results_dir, 'generated',
-                                        f'generated_{context.satellite}_{context.composite}.png')
-    scn.save_datasets(writer='simple_image', filename=generated_image_path)
+    generated_image_path = os.path.join(context.test_results_dir, "generated",
+                                        f"generated_{context.satellite}_{context.composite}.png")
+    scn.save_datasets(writer="simple_image", filename=generated_image_path)
 
     # Save the generated image in the context
     context.generated_image = cv2.imread(generated_image_path)
 
 
-@then('the generated image should be the same as the reference image')
+@then("the generated image should be the same as the reference image")
 def step_then_compare_images(context):
+    """Compare test image to reference image."""
     # Load the images
     imageA = cv2.cvtColor(context.reference_image, cv2.COLOR_BGR2GRAY) # reference_different_image for testing only
     imageB = cv2.cvtColor(context.generated_image, cv2.COLOR_BGR2GRAY)
@@ -81,16 +103,16 @@ def step_then_compare_images(context):
     result_matrix = (array1 != array2).astype(np.uint8) * 255
 
     # Save the resulting numpy array as an image in the difference folder
-    diff_image_path = os.path.join(context.test_results_dir, 'difference',
-                                   f'diff_{context.satellite}_{context.composite}.png')
+    diff_image_path = os.path.join(context.test_results_dir, "difference",
+                                   f"diff_{context.satellite}_{context.composite}.png")
     cv2.imwrite(diff_image_path, result_matrix)
 
     # Count non-zero pixels in the result matrix
     non_zero_count = np.count_nonzero(result_matrix)
 
     # Write the results to a file in the test results directory
-    results_file = os.path.join(context.test_results_dir, 'test_results.txt')
-    with open(results_file, 'a') as f:
+    results_file = os.path.join(context.test_results_dir, "test_results.txt")
+    with open(results_file, "a") as f:
         f.write(f"Test for {context.satellite} - {context.composite}\n")
         f.write(f"Non-zero pixel differences: {non_zero_count}\n")
         if non_zero_count < threshold:
@@ -99,4 +121,6 @@ def step_then_compare_images(context):
             f.write(f"Result: Failed - {non_zero_count} pixel differences exceed the threshold of {threshold}.\n\n")
 
     # Assert that the number of differences is below the threshold
-    assert non_zero_count < threshold, f"Images are not similar enough. {non_zero_count} pixel differences exceed the threshold of {threshold}."
+    assert non_zero_count < threshold, (f"Images are not similar enough. "
+            f"{non_zero_count} pixel differences exceed the threshold of "
+            f"{threshold}.")