From 6e2a3eaf927aa0e9d97040250a7760b99fe0acbb Mon Sep 17 00:00:00 2001
From: Amras <amras0000@gmail.com>
Date: Wed, 8 Nov 2023 17:24:40 +0100
Subject: [PATCH] Rotate images based on EXIF Orientation

This change resolves https://github.com/rr-/szurubooru/issues/470
As well as correcting a related issue with thumbnail rotation.

Based on the EXIF Orientation data,
 we correctly size the scaled image in the post view,
 and rotate the image before creating its thumbnail.
---
 server/szurubooru/func/images.py | 67 ++++++++++++++++++++++++++++----
 1 file changed, 59 insertions(+), 8 deletions(-)

diff --git a/server/szurubooru/func/images.py b/server/szurubooru/func/images.py
index 93b66710..1d55762b 100644
--- a/server/szurubooru/func/images.py
+++ b/server/szurubooru/func/images.py
@@ -16,6 +16,30 @@ from szurubooru import errors
 from szurubooru.func import mime, util
 
 logger = logging.getLogger(__name__)
+logger.setLevel(level=logging.INFO)
+
+# Refer to:
+# https://exiftool.org/TagNames/EXIF.html
+# https://ffmpeg.org/ffmpeg-filters.html#transpose-1
+# https://www.impulseadventure.com/photo/images/orient_flag.gif
+ORIENTATION_FILTER = {
+    "Horizontal (normal)": "null",
+    "Mirror Horizontal": "transpose=clock_flip,transpose=cclock",
+    "Rotate 180": "transpose=clock,transpose=clock",
+    "Mirror vertical": "transpose=clock_flip,transpose=clock",
+    "Mirror horizontal and rotate 270 CW": "transpose=cclock_flip,transpose=clock,transpose=clock",
+    "Rotate 90 CW": "transpose=clock",
+    "Mirror horizontal and rotate 90 CW": "transpose=clock_flip,transpose=clock,transpose=clock",
+    "Rotate 270 CW": "transpose=cclock",
+}
+
+
+ORTHOGONAL_ORIENTATIONS = (
+    "Mirror horizontal and rotate 270 CW",
+    "Rotate 90 CW",
+    "Mirror horizontal and rotate 90 CW",
+    "Rotate 270 CW",
+)
 
 
 def convert_heif_to_png(content: bytes) -> bytes:
@@ -32,10 +56,14 @@ class Image:
 
     @property
     def width(self) -> int:
+        if self._is_orthogonal():
+            return self.info["ImageHeight"]
         return self.info["ImageWidth"]
 
     @property
     def height(self) -> int:
+        if self._is_orthogonal():
+            return self.info["ImageWidth"]
         return self.info["ImageHeight"]
 
     @property
@@ -66,17 +94,32 @@ class Image:
         logger.warning("Unexpected time format(duration=%r)", duration_data)
         return None
 
+    def _orientation_filter(self) -> str:
+        try:
+            return ORIENTATION_FILTER[self.info["Orientation"]]
+        except KeyError:
+            return "null"
+
+    def _is_orthogonal(self) -> bool:
+        try:
+            return self.info["Orientation"] in ORTHOGONAL_ORIENTATIONS
+        except KeyError:
+            return False
+
     def resize_fill(self, width: int, height: int) -> None:
         width_greater = self.width > self.height
         width, height = (-1, height) if width_greater else (width, -1)
 
+        filters = "{orientation},scale='{width}:{height}'".format(
+            orientation=self._orientation_filter(), width=width, height=height)
+
         cli = [
             "-i",
             "{path}",
             "-f",
             "image2",
             "-filter:v",
-            "scale='{width}:{height}'".format(width=width, height=height),
+            filters,
             "-map",
             "0:v:0",
             "-vframes",
@@ -86,9 +129,7 @@ class Image:
             "-",
         ]
         duration = self.duration
-        if (
-            duration is not None and self.info["FileType"] != "SWF"
-        ):
+        if duration is not None and self.info["FileType"] != "SWF":
             total_seconds = duration.total_seconds()
             if total_seconds > 3:
                 cli = [
@@ -108,6 +149,8 @@ class Image:
                 "{path}",
                 "-f",
                 "image2",
+                "-filter:v",
+                self._orientation_filter(),
                 "-map",
                 "0:v:0",
                 "-vframes",
@@ -130,7 +173,7 @@ class Image:
                 "-f",
                 "image2",
                 "-filter_complex",
-                "overlay",
+                "overlay," + self._orientation_filter(),
                 "-map",
                 "0:v:0",
                 "-vframes",
@@ -142,6 +185,7 @@ class Image:
         )
 
     def to_webm(self) -> bytes:
+        filters = self._orientation_filter()
         with util.create_temp_file_path(suffix=".log") as phase_log_path:
             # Pass 1
             self._execute(
@@ -152,6 +196,8 @@ class Image:
                     "1",
                     "-passlogfile",
                     phase_log_path,
+                    "-filter:v",
+                    filters,
                     "-vcodec",
                     "libvpx-vp9",
                     "-crf",
@@ -176,6 +222,8 @@ class Image:
                     "2",
                     "-passlogfile",
                     phase_log_path,
+                    "-filter:v",
+                    filters,
                     "-vcodec",
                     "libvpx-vp9",
                     "-crf",
@@ -204,6 +252,10 @@ class Image:
                 height = self.height - 1
                 altered_dimensions = True
 
+            filters = self._orientation_filter()
+            if altered_dimensions:
+                filters += ",scale='%d:%d'" % (width, height)
+
             args = [
                 "-i",
                 "{path}",
@@ -223,11 +275,10 @@ class Image:
                 "aac",
                 "-f",
                 "mp4",
+                "-filter:v",
+                filters,
             ]
 
-            if altered_dimensions:
-                args += ["-filter:v", "scale='%d:%d'" % (width, height)]
-
             self._execute(args + ["-y", mp4_temp_path])
 
             with open(mp4_temp_path, "rb") as mp4_temp: