handwriting-ocr / src /services /processors /az_processor.py
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import logging
import shutil
from pathlib import Path
from typing import Optional
import cv2
import numpy as np
from tqdm import tqdm
class AZProcessor:
def __init__(self):
self.logger = logging.getLogger(__name__)
self.project_root = Path(__file__).parent.parent.parent.parent
self.source_path = self.project_root / "data" / "raw" / "az_handwritten"
self.temp_path = self.project_root / "data" / "temp" / "AZ"
def _normalize_documentation(self) -> None:
"""Normalize documentation to simplified format (filename label)."""
doc_path = self.temp_path / "documentation.txt"
normalized_path = self.temp_path / "normalized_documentation.txt"
with open(doc_path, 'r') as f, open(normalized_path, 'w') as out:
for line in f:
if line.startswith('#') or not line.strip():
continue
parts = line.strip().split()
if len(parts) >= 2:
filename = parts[0] # First column (filename)
label = parts[-1].upper() # Last column (label)
out.write(f"{filename} {label}\n")
normalized_path.replace(doc_path)
self.logger.info("Documentation normalized to simplified format")
def process(self) -> bool:
try:
self.logger.info("Processing A-Z Handwritten dataset...")
self.temp_path.mkdir(parents=True, exist_ok=True)
if not self.source_path.exists():
self.logger.error(f"Source dataset not found at {self.source_path}")
return False
self._copy_dataset()
self._normalize_documentation()
image_files = list((self.temp_path / "images").glob("*.png"))
total_files = len(image_files)
for idx, img_path in enumerate(tqdm(image_files, desc="Processing A-Z")):
try:
image = cv2.imread(str(img_path), cv2.IMREAD_GRAYSCALE)
if image is None:
self.logger.warning(f"Failed to read image: {img_path}")
continue
processed = self._process_single_image(image)
cv2.imwrite(str(img_path), processed)
progress = (idx + 1) / total_files * 100
self.logger.debug(f"Processed {img_path.name} ({progress:.2f}%)")
except Exception as e:
self.logger.error(f"Error processing {img_path}: {str(e)}")
continue
self.logger.info("A-Z processing completed successfully")
return True
except Exception as e:
self.logger.error(f"Error in A-Z processing: {str(e)}")
return False
def _process_single_image(self, image: np.ndarray) -> np.ndarray:
"""Process single A-Z image through enhancement pipeline."""
image = self._enhance_contrast(image)
image = self._reduce_noise(image)
image = self._center_character(image)
image = self._normalize_stroke(image)
return image
def _enhance_contrast(self, image: np.ndarray) -> np.ndarray:
"""Enhance contrast using CLAHE."""
clahe = cv2.createCLAHE(clipLimit=2.0, tileGridSize=(8,8))
return clahe.apply(image)
def _reduce_noise(self, image: np.ndarray) -> np.ndarray:
"""Remove noise preserving edges."""
denoised = cv2.bilateralFilter(image, d=5, sigmaColor=75, sigmaSpace=75)
_, binary = cv2.threshold(denoised, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
return binary
def _center_character(self, image: np.ndarray) -> np.ndarray:
"""Center character using moments."""
contours, _ = cv2.findContours(image, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
if not contours:
return image
largest_contour = max(contours, key=cv2.contourArea)
M = cv2.moments(largest_contour)
if M["m00"] == 0:
return image
cx = int(M["m10"] / M["m00"])
cy = int(M["m01"] / M["m00"])
rows, cols = image.shape
shift_x = (cols // 2) - cx
shift_y = (rows // 2) - cy
M = np.float32([[1, 0, shift_x], [0, 1, shift_y]])
return cv2.warpAffine(image, M, (cols, rows))
def _normalize_stroke(self, image: np.ndarray) -> np.ndarray:
"""Normalize stroke width."""
kernel_size = max(2, min(image.shape) // 30)
kernel = cv2.getStructuringElement(cv2.MORPH_ELLIPSE, (kernel_size, kernel_size))
return cv2.morphologyEx(image, cv2.MORPH_CLOSE, kernel)
def _copy_dataset(self) -> None:
"""Copy dataset to temp directory."""
if self.source_path.exists():
shutil.copytree(self.source_path, self.temp_path, dirs_exist_ok=True)
self.logger.info(f"Copied dataset to {self.temp_path}")
else:
raise FileNotFoundError(f"Source dataset not found at {self.source_path}")
def test_processor():
"""Test AZ processor functionality."""
import tempfile
test_dir = Path(tempfile.mkdtemp())
try:
img_dir = test_dir / "data" / "raw" / "az_handwritten" / "images"
img_dir.mkdir(parents=True)
# Create test image
test_image = np.zeros((100, 100), dtype=np.uint8)
cv2.putText(test_image, "A", (25, 75), cv2.FONT_HERSHEY_SIMPLEX, 2, 255, 2)
# Add noise
noise = np.random.normal(0, 25, test_image.shape).astype(np.uint8)
noisy_image = cv2.add(test_image, noise)
cv2.imwrite(str(img_dir / "test.png"), noisy_image)
processor = AZProcessor()
processor.project_root = test_dir
processor.source_path = test_dir / "data" / "raw" / "az_handwritten"
processor.temp_path = test_dir / "data" / "temp" / "AZ"
assert processor.process() == True
processed_path = processor.temp_path / "images" / "test.png"
assert processed_path.exists()
processed_img = cv2.imread(str(processed_path), cv2.IMREAD_GRAYSCALE)
assert processed_img is not None
assert np.mean(processed_img) > 0
assert len(np.unique(processed_img)) > 1
print("All tests passed!")
finally:
shutil.rmtree(test_dir)
if __name__ == "__main__":
logging.basicConfig(
level=logging.INFO,
format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
test_processor()