refactor: organize models in submodules (#2845)

* refactor ocr models

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

* refactor vlm api models

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

* refactor vlm_models

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

* refactor picture description

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

* refactor table structure

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

* refactor all into stages

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

---------

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

Author: dolfim-ibm

docling/experimental/pipeline/threaded_layout_vlm_pipeline.py

@@ -32,13 +32,13 @@
 from docling.experimental.datamodel.threaded_layout_vlm_pipeline_options import (
     ThreadedLayoutVlmPipelineOptions,
 )
-from docling.models.api_vlm_model import ApiVlmModel
 from docling.models.base_model import BaseVlmPageModel
-from docling.models.layout_model import LayoutModel
-from docling.models.vlm_models_inline.hf_transformers_model import (
+from docling.models.stages.layout.layout_model import LayoutModel
+from docling.models.vlm_pipeline_models.api_vlm_model import ApiVlmModel
+from docling.models.vlm_pipeline_models.hf_transformers_model import (
     HuggingFaceTransformersVlmModel,
 )
-from docling.models.vlm_models_inline.mlx_model import HuggingFaceMlxModel
+from docling.models.vlm_pipeline_models.mlx_model import HuggingFaceMlxModel
 from docling.pipeline.base_pipeline import BasePipeline
 from docling.pipeline.standard_pdf_pipeline import (
     ProcessingResult,
@@ -162,7 +162,7 @@ def build_prompt(
                     vlm_options=vlm_options,
                 )
             elif vlm_options.inference_framework == InferenceFramework.VLLM:
-                from docling.models.vlm_models_inline.vllm_model import VllmVlmModel
+                from docling.models.vlm_pipeline_models.vllm_model import VllmVlmModel
 
                 self.vlm_model = VllmVlmModel(
                     enabled=True,

docling/models/extraction/__init__.py

@@ -1,10 +1,10 @@
 def ocr_engines():
-    from docling.models.auto_ocr_model import OcrAutoModel
-    from docling.models.easyocr_model import EasyOcrModel
-    from docling.models.ocr_mac_model import OcrMacModel
-    from docling.models.rapid_ocr_model import RapidOcrModel
-    from docling.models.tesseract_ocr_cli_model import TesseractOcrCliModel
-    from docling.models.tesseract_ocr_model import TesseractOcrModel
+    from docling.models.stages.ocr.auto_ocr_model import OcrAutoModel
+    from docling.models.stages.ocr.easyocr_model import EasyOcrModel
+    from docling.models.stages.ocr.ocr_mac_model import OcrMacModel
+    from docling.models.stages.ocr.rapid_ocr_model import RapidOcrModel
+    from docling.models.stages.ocr.tesseract_ocr_cli_model import TesseractOcrCliModel
+    from docling.models.stages.ocr.tesseract_ocr_model import TesseractOcrModel
 
     return {
         "ocr_engines": [
@@ -19,8 +19,12 @@ def ocr_engines():
 
 
 def picture_description():
-    from docling.models.picture_description_api_model import PictureDescriptionApiModel
-    from docling.models.picture_description_vlm_model import PictureDescriptionVlmModel
+    from docling.models.stages.picture_description.picture_description_api_model import (
+        PictureDescriptionApiModel,
+    )
+    from docling.models.stages.picture_description.picture_description_vlm_model import (
+        PictureDescriptionVlmModel,
+    )
 
     return {
         "picture_description": [
@@ -34,7 +38,7 @@ def layout_engines():
     from docling.experimental.models.table_crops_layout_model import (
         TableCropsLayoutModel,
     )
-    from docling.models.layout_model import LayoutModel
+    from docling.models.stages.layout.layout_model import LayoutModel
 
     return {
         "layout_engines": [
@@ -45,7 +49,9 @@ def layout_engines():
 
 
 def table_structure_engines():
-    from docling.models.table_structure_model import TableStructureModel
+    from docling.models.stages.table_structure.table_structure_model import (
+        TableStructureModel,
+    )
 
     return {
         "table_structure_engines": [