enh: image prompt enhancer

backend/open_webui/config.py

@@ -1055,6 +1055,32 @@ JSON format: { "tags": ["tag1", "tag2", "tag3"] }
 {{MESSAGES:END:6}}
 </chat_history>"""
 
+IMAGE_PROMPT_GENERATION_PROMPT_TEMPLATE = PersistentConfig(
+    "IMAGE_PROMPT_GENERATION_PROMPT_TEMPLATE",
+    "task.image.prompt_template",
+    os.environ.get("IMAGE_PROMPT_GENERATION_PROMPT_TEMPLATE", ""),
+)
+
+DEFAULT_IMAGE_PROMPT_GENERATION_PROMPT_TEMPLATE = """### Task:
+Generate a detailed prompt for am image generation task based on the given language and context. Describe the image as if you were explaining it to someone who cannot see it. Include relevant details, colors, shapes, and any other important elements.
+
+### Guidelines:
+- Be descriptive and detailed, focusing on the most important aspects of the image.
+- Avoid making assumptions or adding information not present in the image.
+- Use the chat's primary language; default to English if multilingual.
+- If the image is too complex, focus on the most prominent elements.
+
+### Output:
+Strictly return in JSON format:
+{
+    "prompt": "Your detailed description here."
+}
+
+### Chat History:
+<chat_history>
+{{MESSAGES:END:6}}
+</chat_history>"""
+
 ENABLE_TAGS_GENERATION = PersistentConfig(
     "ENABLE_TAGS_GENERATION",
     "task.tags.enable",