Updated prompt to extract text and format it in Markdown, including a…

src/markitdown/_markitdown.py

@@ -1087,7 +1087,40 @@ def convert(self, local_path, **kwargs) -> Union[None, DocumentConverterResult]:
 
     def _get_llm_description(self, local_path, extension, client, model, prompt=None):
         if prompt is None or prompt.strip() == "":
-            prompt = "Write a detailed caption for this image."
+            prompt = '''
+                Analyze the image and extract all visible text in the original language. Reproduce the extracted text in a structured Markdown format, preserving any formatting such as headings, bullet points, and highlights. Ensure the output accurately reflects the structure and style of the original document.
+
+                Follow these additional guidelines based on the content type:
+
+                **Tables:**
+                    * Create exact markdown representation of the table using markdown syntax (|column1|column2|)
+                    * Create a separator row (|---|---|) after the header
+                    * Transcribe all values exactly as they appear in the table
+
+                **Mathematical Formulas:**
+                    * Use LaTeX notation within markdown delimiters, e.g., `$$ y = mx + b $$`
+
+                **Charts and Graphs:**
+                    * Identify the graph type (bar, line, pie, etc.)
+                    * Extract data points into a markdown table
+                    * Include axis labels, units, and scale information
+                    * Describe patterns (e.g., linear, exponential) under markdown headers
+                    * Record maximums, minimums, and important values
+
+                **Flowcharts and Diagrams:**
+                    * Use mermaid markdown syntax where possible:
+                ```mermaid
+                graph LR
+                    A-->B
+                    B-->C
+                ```
+                    * For process flows, create a numbered list with clear step progression and any branching conditions
+                    * For technical diagrams, list components and their relationships in a structured way, preserving measurements/specifications in tables
+
+                For any visual elements that cannot be represented directly in Markdown, describe them in plain text under a section titled "Visual Notes."
+
+                Maintain numerical precision exactly as shown, preserve all labels and annotations as markdown text, and structure the output for both human and machine readability. Output only the converted Markdown text without any additional commentary or explanations.
+            '''
 
         data_uri = ""
         with open(local_path, "rb") as image_file: