add script callback for before image save and change callback for after image save to use a class with parameters

modules/images.py

@@ -451,17 +451,6 @@ def save_image(image, path, basename, seed=None, prompt=None, extension='png', i
     """
     namegen = FilenameGenerator(p, seed, prompt)
 
-    if extension == 'png' and opts.enable_pnginfo and info is not None:
-        pnginfo = PngImagePlugin.PngInfo()
-
-        if existing_info is not None:
-            for k, v in existing_info.items():
-                pnginfo.add_text(k, str(v))
-
-        pnginfo.add_text(pnginfo_section_name, info)
-    else:
-        pnginfo = None
-
     if save_to_dirs is None:
         save_to_dirs = (grid and opts.grid_save_to_dirs) or (not grid and opts.save_to_dirs and not no_prompt)
 
@@ -489,19 +478,27 @@ def save_image(image, path, basename, seed=None, prompt=None, extension='png', i
         if add_number:
             basecount = get_next_sequence_number(path, basename)
             fullfn = None
-            fullfn_without_extension = None
             for i in range(500):
                 fn = f"{basecount + i:05}" if basename == '' else f"{basename}-{basecount + i:04}"
                 fullfn = os.path.join(path, f"{fn}{file_decoration}.{extension}")
-                fullfn_without_extension = os.path.join(path, f"{fn}{file_decoration}")
                 if not os.path.exists(fullfn):
                     break
         else:
             fullfn = os.path.join(path, f"{file_decoration}.{extension}")
-            fullfn_without_extension = os.path.join(path, file_decoration)
     else:
         fullfn = os.path.join(path, f"{forced_filename}.{extension}")
-        fullfn_without_extension = os.path.join(path, forced_filename)
+
+    pnginfo = existing_info or {}
+    if info is not None:
+        pnginfo[pnginfo_section_name] = info
+
+    params = script_callbacks.ImageSaveParams(image, p, fullfn, pnginfo)
+    script_callbacks.before_image_saved_callback(params)
+
+    image = params.image
+    fullfn = params.filename
+    info = params.pnginfo.get(pnginfo_section_name, None)
+    fullfn_without_extension, extension = os.path.splitext(params.filename)
 
     def exif_bytes():
         return piexif.dump({
@@ -510,12 +507,20 @@ def save_image(image, path, basename, seed=None, prompt=None, extension='png', i
             },
         })
 
-    if extension.lower() in ("jpg", "jpeg", "webp"):
+    if extension.lower() == '.png':
+        pnginfo_data = PngImagePlugin.PngInfo()
+        for k, v in params.pnginfo.items():
+            pnginfo_data.add_text(k, str(v))
+
+        image.save(fullfn, quality=opts.jpeg_quality, pnginfo=pnginfo_data)
+
+    elif extension.lower() in (".jpg", ".jpeg", ".webp"):
         image.save(fullfn, quality=opts.jpeg_quality)
+
         if opts.enable_pnginfo and info is not None:
             piexif.insert(exif_bytes(), fullfn)
     else:
-        image.save(fullfn, quality=opts.jpeg_quality, pnginfo=pnginfo)
+        image.save(fullfn, quality=opts.jpeg_quality)
 
     target_side_length = 4000
     oversize = image.width > target_side_length or image.height > target_side_length
@@ -538,7 +543,8 @@ def save_image(image, path, basename, seed=None, prompt=None, extension='png', i
     else:
         txt_fullfn = None
 
-    script_callbacks.image_saved_callback(image, p, fullfn, txt_fullfn)
+    script_callbacks.image_saved_callback(params)
+
     return fullfn, txt_fullfn
 
 

modules/script_callbacks.py

@@ -9,15 +9,34 @@ def report_exception(c, job):
     print(traceback.format_exc(), file=sys.stderr)
 
 
+class ImageSaveParams:
+    def __init__(self, image, p, filename, pnginfo):
+        self.image = image
+        """the PIL image itself"""
+
+        self.p = p
+        """p object with processing parameters; either StableDiffusionProcessing or an object with same fields"""
+
+        self.filename = filename
+        """name of file that the image would be saved to"""
+
+        self.pnginfo = pnginfo
+        """dictionary with parameters for image's PNG info data; infotext will have the key 'parameters'"""
+
+
 ScriptCallback = namedtuple("ScriptCallback", ["script", "callback"])
 callbacks_model_loaded = []
 callbacks_ui_tabs = []
 callbacks_ui_settings = []
+callbacks_before_image_saved = []
 callbacks_image_saved = []
 
+
 def clear_callbacks():
     callbacks_model_loaded.clear()
     callbacks_ui_tabs.clear()
+    callbacks_ui_settings.clear()
+    callbacks_before_image_saved.clear()
     callbacks_image_saved.clear()
 
 
@@ -49,10 +68,18 @@ def ui_settings_callback():
             report_exception(c, 'ui_settings_callback')
 
 
-def image_saved_callback(image, p, fullfn, txt_fullfn):
+def before_image_saved_callback(params: ImageSaveParams):
     for c in callbacks_image_saved:
         try:
-            c.callback(image, p, fullfn, txt_fullfn)
+            c.callback(params)
+        except Exception:
+            report_exception(c, 'before_image_saved_callback')
+
+
+def image_saved_callback(params: ImageSaveParams):
+    for c in callbacks_image_saved:
+        try:
+            c.callback(params)
         except Exception:
             report_exception(c, 'image_saved_callback')
 
@@ -64,7 +91,6 @@ def add_callback(callbacks, fun):
     callbacks.append(ScriptCallback(filename, fun))
 
 
-
 def on_model_loaded(callback):
     """register a function to be called when the stable diffusion model is created; the model is
     passed as an argument"""
@@ -90,11 +116,17 @@ def on_ui_settings(callback):
     add_callback(callbacks_ui_settings, callback)
 
 
+def on_before_image_saved(callback):
+    """register a function to be called before an image is saved to a file.
+    The callback is called with one argument:
+        - params: ImageSaveParams - parameters the image is to be saved with. You can change fields in this object.
+    """
+    add_callback(callbacks_before_image_saved, callback)
+
+
 def on_image_saved(callback):
-    """register a function to be called after modules.images.save_image is called.
-    The callback is called with three arguments:
-        - p - procesing object (or a dummy object with same fields if the image is saved using save button)
-        - fullfn - image filename
-        - txt_fullfn - text file with parameters; may be None
+    """register a function to be called after an image is saved to a file.
+    The callback is called with one argument:
+        - params: ImageSaveParams - parameters the image was saved with. Changing fields in this object does nothing.
     """
     add_callback(callbacks_image_saved, callback)