Better (?) default left margin

copienator/commands/cutleft.py

@@ -26,6 +26,7 @@ from copienator import (
 from copienator.filesystem import staged_files
 from copienator.copy_errors import clear_copy_error, mark_copy_error, marked_copy_paths
 from copienator.configuration import SHOW_PERSONAL_STEPS
+from copienator.left_margin import analyse_margins
 
 DELIMITER_WIDTH = 5
 DELIMITER_COLOR = (0, 0, 0)
@@ -34,6 +35,7 @@ CROP_SHIFT_STEP = 50
 CROP_WIDTH_STEP = 50
 RENDER_DPI = 200
 NARROW_PAGE_RATIO = 0.8
+AUTO_STRIP_WIDTH_FACTOR = 1.10
 pdf_cache_lock = threading.Lock()
 
 # The requested spelling is kept as the public switch for this alternate layout.
@@ -116,6 +118,9 @@ def process_single_pdf(
     shift_offset: int = 0,
     max_per_file: int = 5,
     width_offset: int = 0,
+    *,
+    automatic_margin: bool = True,
+    margin_analysis: dict | None = None,
 ) -> tuple[Image.Image, list[Image.Image], dict[str, object]] | None:
     """Convert one PDF into a preview, full-resolution splits and metadata."""
     try:
@@ -124,7 +129,10 @@ def process_single_pdf(
         if not images:
             return None
         reference_width = normal_page_width(pdf_path, images)
+        if automatic_margin and max_per_file != 1 and margin_analysis is None:
+            margin_analysis = analyse_margins(images, RENDER_DPI, reference_width)
         full_width_pages = []
+        page_crops = []
         for page_index, image in enumerate(images):
             width, height = image.size
             if max_per_file == 1:
@@ -140,8 +148,17 @@ def process_single_pdf(
                     width,
                     width // 3 + 100 + shift_offset + max(0, width_offset),
                 )
+            if automatic_margin and max_per_file != 1:
+                left = min(width - 1, max(0, margin_analysis['starts_px'][page_index] + shift_offset))
+                strip_width = round(
+                    ((reference_width if width < NARROW_PAGE_RATIO * reference_width else width) // 3)
+                    * AUTO_STRIP_WIDTH_FACTOR
+                )
+                right = min(width, left + strip_width + max(0, width_offset))
             if right > left:
                 cropped_images.append(image.crop((left, 0, right, height)))
+                page_crops.append({'page': page_index + 1, 'left_px': left, 'right_px': right,
+                                   'width_px': width, 'height_px': height})
                 if left == 0 and right == width:
                     full_width_pages.append(page_index + 1)
         if not cropped_images:
@@ -165,6 +182,8 @@ def process_single_pdf(
             "number_of_files": len(split_images),
             "columns_per_file": distribution,
             "full_width_pages": full_width_pages,
+            "page_crops": page_crops,
+            "auto_margin": margin_analysis if automatic_margin and max_per_file != 1 else None,
         }
         return preview, split_images, schema
     except Exception as exc:  # noqa: BLE001 - interactive item failure
@@ -208,6 +227,7 @@ class ImageReviewer:
         files: list[Path],
         output_dir: Path,
         default_max_per_file: int = 5,
+        automatic_margin: bool = True,
     ) -> None:
         self.files = files
         self.output_dir = output_dir
@@ -216,6 +236,8 @@ class ImageReviewer:
         self.had_errors = False
         self.stop_prefetch = threading.Event()
         self.current_result = None
+        self.automatic_margin = automatic_margin
+        self.margin_analysis = None
         self.index = 0
         self.current_shift = 0
         self.current_width_offset = 0
@@ -283,6 +305,7 @@ class ImageReviewer:
         self.current_shift = 0
         self.current_width_offset = 0
         self.current_result = None
+        self.margin_analysis = None
         self.trigger_processing(self.files[self.index], self.current_shift)
 
     def trigger_processing(self, pdf_path: Path, shift: int) -> None:
@@ -299,6 +322,8 @@ class ImageReviewer:
                     shift,
                     self.current_max_per_file,
                     self.current_width_offset,
+                    automatic_margin=self.automatic_margin,
+                    margin_analysis=self.margin_analysis,
                 )
             )
 
@@ -325,6 +350,8 @@ class ImageReviewer:
     ) -> None:
         self.current_preview = result[0]
         self.current_result = result
+        if result[2].get('auto_margin') is not None:
+            self.margin_analysis = result[2]['auto_margin']
         self.update_display(pdf_path.name, result[2])
 
     def update_display(self, filename: str, schema: dict[str, object]) -> None:
@@ -338,6 +365,17 @@ class ImageReviewer:
             if personnal_binding
             else ""
         )
+        analysis = schema.get('auto_margin')
+        margin_info = ''
+        if analysis:
+            offsets = sorted({round(crop['left_px'] * 25.4 / RENDER_DPI, 1)
+                              for crop in schema['page_crops']})
+            needs_review = any(group['status'] in {'inconsistent', 'uncertain', 'insufficient-ink'}
+                               for group in analysis['groups'])
+            margin_info = (f"Auto margin: {offsets} mm from left"
+                           + (' | Check uncertain pages' if needs_review else '') + '\n')
+            if analysis.get('no_margin_from_page') is not None:
+                margin_info += f"No margin from page {analysis['no_margin_from_page']} onwards\n"
         self.label_info.configure(
             text=(
                 f"[{self.index + 1}/{len(self.files)}] {filename} | "
@@ -345,6 +383,7 @@ class ImageReviewer:
                 f"Extra width: {self.current_width_offset}px\n"
                 f"Files: {schema['number_of_files']} | "
                 f"Cols: {schema['columns_per_file']}\n"
+                f"{margin_info}"
                 "Arrows: left/right move by 50px | up/down widen/narrow by 50px\n"
                 "Enter: Save and next | !: flag error and skip | 1: use full pages"
                 f"{personal_instructions}"
@@ -428,6 +467,7 @@ def run(
     fullpage: bool = False,
     no_visual_check: bool = False,
     marked: bool = False,
+    automatic_margin: bool = True,
 ) -> ExitCode:
     files = marked_copy_paths(workspace) if marked else _selected_files(workspace, target)
     if not files:
@@ -463,6 +503,7 @@ def run(
         files,
         workspace.cutleft_dir,
         default_max_per_file=1 if fullpage else 5,
+        automatic_margin=automatic_margin,
     )
     if not reviewer.completed:
         return ExitCode.INTERRUPTED
@@ -472,6 +513,10 @@ def run(
 def build_parser() -> argparse.ArgumentParser:
     parser = target_parser("Interactively crop the label margin from PDF copies")
     parser.add_argument("--marked", action="store_true", help="Review flagged copies and clear only margin-cropping flags after saving with Enter")
+    parser.add_argument(
+        '--manual-margin', action='store_true',
+        help='Use the previous fixed margin instead of automatically estimating body-text positions',
+    )
     parser.add_argument(
         "--fullpage",
         action="store_true",
@@ -496,6 +541,7 @@ def main(argv: Sequence[str] | None = None) -> int:
             fullpage=args.fullpage,
             no_visual_check=args.no_visual_check,
             marked=args.marked,
+            automatic_margin=not args.manual_margin,
         )
 
     return execute(parser, argv, handle)