Implemented OCR Functionality

Data/Python_API_Endpoints/ocr_engines.py

@@ -0,0 +1,85 @@
+import os
+import io
+import base64
+import torch
+import pytesseract
+import easyocr
+import numpy as np
+from PIL import Image
+
+# ---------------------------------------------------------------------
+# Configure internal Tesseract path
+# ---------------------------------------------------------------------
+BASE_DIR = os.path.dirname(os.path.abspath(__file__))
+TESSERACT_FOLDER = os.path.join(BASE_DIR, "Tesseract-OCR")
+TESSERACT_EXE = os.path.join(TESSERACT_FOLDER, "tesseract.exe")
+TESSDATA_DIR = os.path.join(TESSERACT_FOLDER, "tessdata")
+
+if not os.path.isfile(TESSERACT_EXE):
+    raise EnvironmentError("Missing tesseract.exe in /Tesseract-OCR. Ensure the full folder is copied.")
+
+pytesseract.pytesseract.tesseract_cmd = TESSERACT_EXE
+os.environ["TESSDATA_PREFIX"] = TESSDATA_DIR
+
+# ---------------------------------------------------------------------
+# EasyOCR Global Instances
+# ---------------------------------------------------------------------
+easyocr_reader_cpu = None
+easyocr_reader_gpu = None
+
+def initialize_ocr_engines():
+    global easyocr_reader_cpu, easyocr_reader_gpu
+    if easyocr_reader_cpu is None:
+        easyocr_reader_cpu = easyocr.Reader(['en'], gpu=False)
+    if easyocr_reader_gpu is None:
+        easyocr_reader_gpu = easyocr.Reader(['en'], gpu=torch.cuda.is_available())
+
+# ---------------------------------------------------------------------
+# Main OCR Handler
+# ---------------------------------------------------------------------
+def run_ocr_on_base64(image_b64: str, engine: str = "tesseract", backend: str = "cpu") -> list[str]:
+    if not image_b64:
+        raise ValueError("No base64 image data provided.")
+
+    try:
+        raw_bytes = base64.b64decode(image_b64)
+        image = Image.open(io.BytesIO(raw_bytes)).convert("RGB")
+    except Exception as e:
+        raise ValueError(f"Invalid base64 image input: {e}")
+
+    engine = engine.lower().strip()
+    backend = backend.lower().strip()
+
+    if engine in ["tesseract", "tesseractocr"]:
+        try:
+            text = pytesseract.image_to_string(image, config="--psm 6 --oem 1")
+        except pytesseract.TesseractNotFoundError:
+            raise RuntimeError("Tesseract binary not found in internal folder.")
+    elif engine == "easyocr":
+        initialize_ocr_engines()
+        reader = easyocr_reader_gpu if backend == "gpu" else easyocr_reader_cpu
+        result = reader.readtext(np.array(image), detail=1)
+
+        # Group by Y position (line-aware sorting)
+        result = sorted(result, key=lambda r: r[0][0][1])
+        lines = []
+        current_line = []
+        last_y = None
+        line_threshold = 10
+
+        for (bbox, text, _) in result:
+            y = bbox[0][1]
+            if last_y is None or abs(y - last_y) < line_threshold:
+                current_line.append(text)
+            else:
+                lines.append(" ".join(current_line))
+                current_line = [text]
+            last_y = y
+
+        if current_line:
+            lines.append(" ".join(current_line))
+        text = "\n".join(lines)
+    else:
+        raise ValueError(f"OCR engine '{engine}' not recognized.")
+
+    return [line.strip() for line in text.splitlines() if line.strip()]