Merge pull request #4173 from evshiron/fix/encode-pnginfo

add back png info in image api

modules/api/api.py

@@ -10,6 +10,7 @@ from modules.api.models import *
 from modules.processing import StableDiffusionProcessingTxt2Img, StableDiffusionProcessingImg2Img, process_images
 from modules.sd_samplers import all_samplers
 from modules.extras import run_extras, run_pnginfo
+from PIL import PngImagePlugin
 from modules.sd_models import checkpoints_list
 from modules.realesrgan_model import get_realesrgan_models
 from typing import List
@@ -34,9 +35,21 @@ def setUpscalers(req: dict):
 
 
 def encode_pil_to_base64(image):
-    buffer = io.BytesIO()
-    image.save(buffer, format="png")
-    return base64.b64encode(buffer.getvalue())
+    with io.BytesIO() as output_bytes:
+
+        # Copy any text-only metadata
+        use_metadata = False
+        metadata = PngImagePlugin.PngInfo()
+        for key, value in image.info.items():
+            if isinstance(key, str) and isinstance(value, str):
+                metadata.add_text(key, value)
+                use_metadata = True
+
+        image.save(
+            output_bytes, "PNG", pnginfo=(metadata if use_metadata else None)
+        )
+        bytes_data = output_bytes.getvalue()
+    return base64.b64encode(bytes_data)
 
 
 class Api:
@@ -205,7 +218,7 @@ class Api:
         shared.state.interrupt()
 
         return {}
-        
+
     def get_config(self):
         options = {}
         for key in shared.opts.data.keys():
@@ -214,9 +227,9 @@ class Api:
                 options.update({key: shared.opts.data.get(key, shared.opts.data_labels.get(key).default)})
             else:
                 options.update({key: shared.opts.data.get(key, None)})
-        
+
         return options
-        
+
     def set_config(self, req: OptionsModel):
         # currently req has all options fields even if you send a dict like { "send_seed": false }, which means it will
         # overwrite all options with default values.
@@ -237,13 +250,13 @@ class Api:
 
     def get_upscalers(self):
         upscalers = []
-        
+
         for upscaler in shared.sd_upscalers:
             u = upscaler.scaler
             upscalers.append({"name":u.name, "model_name":u.model_name, "model_path":u.model_path, "model_url":u.model_url})
-        
+
         return upscalers
-        
+
     def get_sd_models(self):
         return [{"title":x.title, "model_name":x.model_name, "hash":x.hash, "filename": x.filename, "config": x.config} for x in checkpoints_list.values()]
 
@@ -255,11 +268,11 @@ class Api:
 
     def get_realesrgan_models(self):
         return [{"name":x.name,"path":x.data_path, "scale":x.scale} for x in get_realesrgan_models(None)]
-    
+
     def get_promp_styles(self):
         styleList = []
         for k in shared.prompt_styles.styles:
-            style = shared.prompt_styles.styles[k] 
+            style = shared.prompt_styles.styles[k]
             styleList.append({"name":style[0], "prompt": style[1], "negative_prompr": style[2]})
 
         return styleList