From 0761984bcd10a65d44e432895a5afa414366925f Mon Sep 17 00:00:00 2001
From: dgtlmoon <dgtlmoon@gmail.com>
Date: Sat, 12 Feb 2022 23:37:02 +0100
Subject: [PATCH] tweaks to image diff highlighter

---
 changedetectionio/__init__.py               | 20 ++++++++--
 changedetectionio/image_diff.py             | 41 +++++++++++++++++++++
 changedetectionio/templates/diff-image.html | 19 +++++++++-
 3 files changed, 76 insertions(+), 4 deletions(-)
 create mode 100644 changedetectionio/image_diff.py

diff --git a/changedetectionio/__init__.py b/changedetectionio/__init__.py
index a3ad7a3f..2654e0bf 100644
--- a/changedetectionio/__init__.py
+++ b/changedetectionio/__init__.py
@@ -808,10 +808,24 @@ def changedetection_app(config=None, datastore_o=None):
         return output
 
     # render an image which contains the diff of two images
-    @app.route("/diff/image/<string:uuid>/<string:first_date>/<string:second_date>")
-    def render_diff_image(uuid, first_date, second_date):
+    # We always compare the newest against whatever compare_date we are given
+    @app.route("/diff/image/<string:uuid>/<string:compare_date>")
+    def render_diff_image(uuid, compare_date):
+        from changedetectionio import image_diff
+
         from flask import make_response
-        resp = make_response("xxxxx")
+        watch = datastore.data['watching'][uuid]
+        newest = list(watch['history'].keys())[-1]
+
+        # @todo this is weird
+        if compare_date == 'None' or compare_date is None:
+            second_date = list(watch['history'].keys())[0]
+
+        new_img = watch['history'][newest]
+        prev_img = watch['history'][second_date]
+        img = image_diff.render_diff(new_img, prev_img)
+
+        resp = make_response(img)
         resp.headers['Content-Type'] = 'image/jpeg'
         return resp
 
diff --git a/changedetectionio/image_diff.py b/changedetectionio/image_diff.py
new file mode 100644
index 00000000..fe4e5fd4
--- /dev/null
+++ b/changedetectionio/image_diff.py
@@ -0,0 +1,41 @@
+# import the necessary packages
+from skimage.metrics import structural_similarity as compare_ssim
+import argparse
+import imutils
+import cv2
+
+# From https://www.pyimagesearch.com/2017/06/19/image-difference-with-opencv-and-python/
+def render_diff(fpath_imageA, fpath_imageB):
+
+	imageA = cv2.imread(fpath_imageA)
+	imageB = cv2.imread(fpath_imageB)
+
+	# convert the images to grayscale
+	grayA = cv2.cvtColor(imageA, cv2.COLOR_BGR2GRAY)
+	grayB = cv2.cvtColor(imageB, cv2.COLOR_BGR2GRAY)
+
+	# compute the Structural Similarity Index (SSIM) between the two
+	# images, ensuring that the difference image is returned
+	(score, diff) = compare_ssim(grayA, grayB, full=True)
+	diff = (diff * 255).astype("uint8")
+	print("SSIM: {}".format(score))
+
+	# threshold the difference image, followed by finding contours to
+	# obtain the regions of the two input images that differ
+	thresh = cv2.threshold(diff, 0, 255,
+		cv2.THRESH_BINARY_INV | cv2.THRESH_OTSU)[1]
+	cnts = cv2.findContours(thresh.copy(), cv2.RETR_EXTERNAL,
+		cv2.CHAIN_APPROX_SIMPLE)
+	cnts = imutils.grab_contours(cnts)
+
+	# loop over the contours
+	for c in cnts:
+		# compute the bounding box of the contour and then draw the
+		# bounding box on both input images to represent where the two
+		# images differ
+		(x, y, w, h) = cv2.boundingRect(c)
+		cv2.rectangle(imageA, (x, y), (x + w, y + h), (0, 0, 255), 2)
+		cv2.rectangle(imageB, (x, y), (x + w, y + h), (0, 0, 255), 2)
+
+	#return cv2.imencode('.jpg', imageB)[1].tobytes()
+	return cv2.imencode('.jpg', imageB)[1].tobytes()
\ No newline at end of file
diff --git a/changedetectionio/templates/diff-image.html b/changedetectionio/templates/diff-image.html
index 9e3b81e9..19b16569 100644
--- a/changedetectionio/templates/diff-image.html
+++ b/changedetectionio/templates/diff-image.html
@@ -23,11 +23,28 @@
 </div>
 
 <div id="diff-ui">
-  <img src="{{ url_for('render_diff_image', uuid=uuid, first_date=versions[0], second_date=current_previous_version) }}" />
+  <img style="max-width: 100%" src="{{ url_for('render_diff_image', uuid=uuid, compare_date=current_previous_version) }}" />
 </div>
 
 
 <script type="text/javascript" src="{{url_for('static_content', group='js', filename='diff.js')}}"></script>
 
+<script defer="">
+window.onload = function() {
+    /* Set current version date as local time in the browser also */
+    var current_v = document.getElementById("current-v-date");
+    var dateObject = new Date({{ newest_version_timestamp }}*1000);
+    current_v.innerHTML=dateObject.toLocaleString();
+
+    /* Convert what is options from UTC time.time() to local browser time */
+    var diffList=document.getElementById("diff-version");
+    if (typeof(diffList) != 'undefined' && diffList != null) {
+        for (var option of diffList.options) {
+          var dateObject = new Date(option.value*1000);
+          option.label=dateObject.toLocaleString();
+        }
+    }
+}
+</script>
 
 {% endblock %}
\ No newline at end of file