add img2img_extra_noise for backend original

modules/script_callbacks.py

@@ -27,6 +27,18 @@ class ImageSaveParams:
         """dictionary with parameters for image's PNG info data; infotext will have the key 'parameters'"""
 
 
+class ExtraNoiseParams:
+    def __init__(self, noise, x, xi):
+        self.noise = noise
+        """Random noise generated by the seed"""
+
+        self.x = x
+        """Latent representation of the image"""
+
+        self.xi = xi
+        """Noisy latent representation of the image"""
+
+
 class CFGDenoiserParams:
     def __init__(self, x, image_cond, sigma, sampling_step, total_sampling_steps, text_cond, text_uncond):
         self.x = x
@@ -246,6 +258,14 @@ def image_save_btn_callback(filename: str):
             report_exception(e, c, 'image_save_btn_callback')
 
 
+def extra_noise_callback(params: ExtraNoiseParams):
+    for c in callback_map['callbacks_extra_noise']:
+        try:
+            c.callback(params)
+        except Exception as e:
+            report_exception(e, c, 'callbacks_extra_noise')
+
+
 def cfg_denoiser_callback(params: CFGDenoiserParams):
     for c in callback_map['callbacks_cfg_denoiser']:
         try:
@@ -437,6 +457,14 @@ def on_image_save_btn(callback):
     add_callback(callback_map['callbacks_image_save_btn'], callback)
 
 
+def on_extra_noise(callback):
+    """register a function to be called before adding extra noise in img2img or hires fix;
+    The callback is called with one argument:
+        - params: ExtraNoiseParams - contains noise determined by seed and latent representation of image
+    """
+    add_callback(callback_map['callbacks_extra_noise'], callback)
+
+
 def on_cfg_denoiser(callback):
     """register a function to be called in the kdiffussion cfg_denoiser method after building the inner model inputs.
     The callback is called with one argument: