Implement border detection

base_proxy.py

@@ -3,6 +3,24 @@ from pathlib import Path
 CARD_W_INCHES = 2.48031  # 63mm
 CARD_H_INCHES = 3.46457  # 88mm
 
+W_INCHES_EXPECTED = 2.72
+H_INCHES_EXPECTED = 3.7
+
 LEAVE_BLEED_INCHES = 0.04
 
 BASE_DIR = Path(__file__).parent
+
+SAVE_INTERMEDIATE_FOR_DEBUG = False
+
+
+def make_intermediate_name(input_path: Path, infix: str):
+    return BASE_DIR / 'cropped_cards' / f'{input_path.stem}.{infix}.jpg'
+
+
+def in_to_px(inches: float, dpi: int) -> int:
+    return round(inches * dpi)
+
+
+def mil_to_px(mils: int, dpi: int) -> int:
+    return int(mils * dpi // 1000)
+