ocr / app.py
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import os
import io
import sys
import cv2
import base64
import pickle
import numpy as np
import tensorflow as tf
import matplotlib.pyplot as plt
import matplotlib.font_manager as fm
import tempfile
import sakshi_ocr
from fastapi import FastAPI, File, UploadFile, HTTPException
from fastapi.responses import HTMLResponse, JSONResponse
# Define paths to your assets (update these if necessary)
MODEL_PATH = 'hindi_ocr_model.keras'
ENCODER_PATH = 'label_encoder.pkl'
FONT_PATH = 'NotoSansDevanagari-Regular.ttf'
# Load custom font if available
if os.path.exists(FONT_PATH):
fm.fontManager.addfont(FONT_PATH)
plt.rcParams['font.family'] = 'Noto Sans Devanagari'
else:
print("Custom font not found. Using default font.")
# Load the OCR model
def load_model():
if not os.path.exists(MODEL_PATH):
raise FileNotFoundError(f"Model file not found at {MODEL_PATH}")
return tf.keras.models.load_model(MODEL_PATH)
# Load the label encoder
def load_label_encoder():
if not os.path.exists(ENCODER_PATH):
raise FileNotFoundError(f"Label encoder file not found at {ENCODER_PATH}")
with open(ENCODER_PATH, 'rb') as f:
return pickle.load(f)
# Global loading so they persist across requests
model = load_model()
label_encoder = load_label_encoder()
# Function for word detection
def detect_words(image):
# Assume input is a grayscale image
_, binary = cv2.threshold(image, 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)
kernel = np.ones((3, 3), np.uint8)
dilated = cv2.dilate(binary, kernel, iterations=2)
contours, _ = cv2.findContours(dilated, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
word_img = cv2.cvtColor(image, cv2.COLOR_GRAY2BGR)
word_count = 0
for contour in contours:
x, y, w, h = cv2.boundingRect(contour)
if w > 10 and h > 10:
cv2.rectangle(word_img, (x, y), (x+w, y+h), (0, 255, 0), 2)
word_count += 1
return word_img, word_count
# Function to run Sakshi OCR and capture its output
def run_sakshi_ocr(image_path):
buffer = io.StringIO()
old_stdout = sys.stdout
sys.stdout = buffer
try:
sakshi_ocr.generate(image_path)
finally:
sys.stdout = old_stdout
return buffer.getvalue()
# Utility function: convert image (numpy array) to a base64 encoded string
def image_to_base64(image, ext=".png"):
success, encoded_image = cv2.imencode(ext, image)
if not success:
return None
return base64.b64encode(encoded_image).decode('utf-8')
# Initialize FastAPI app
app = FastAPI(title="Hindi OCR App by sakshi")
@app.get("/", response_class=HTMLResponse)
async def root():
html_content = """
<html>
<head>
<title>Hindi OCR App by sakshi</title>
</head>
<body>
<h1>Hindi OCR App by sakshi</h1>
<form action="/predict" enctype="multipart/form-data" method="post">
<input name="file" type="file" accept="image/*">
<input type="submit" value="Upload and Predict">
</form>
</body>
</html>
"""
return HTMLResponse(content=html_content)
@app.post("/predict")
async def predict(file: UploadFile = File(...)):
# Read and decode the uploaded image
contents = await file.read()
nparr = np.frombuffer(contents, np.uint8)
img = cv2.imdecode(nparr, cv2.IMREAD_GRAYSCALE)
if img is None:
raise HTTPException(status_code=400, detail="Error reading the image.")
# Encode the original image to base64 for visualization
original_image = image_to_base64(cv2.cvtColor(img, cv2.COLOR_GRAY2BGR))
# Word detection
word_img, word_count = detect_words(img)
word_img_encoded = image_to_base64(word_img)
# OCR model prediction for single word
try:
img_resized = cv2.resize(img, (128, 32))
img_norm = img_resized / 255.0
img_input = img_norm[np.newaxis, ..., np.newaxis] # shape: (1, 32, 128, 1)
pred = model.predict(img_input)
pred_label_idx = np.argmax(pred)
pred_label = label_encoder.inverse_transform([pred_label_idx])[0]
# Generate an image with the prediction using matplotlib
fig, ax = plt.subplots()
ax.imshow(img, cmap='gray')
ax.set_title(f"Predicted: {pred_label}", fontsize=12)
ax.axis('off')
buf = io.BytesIO()
plt.savefig(buf, format="png")
buf.seek(0)
pred_img_array = np.frombuffer(buf.getvalue(), np.uint8)
prediction_img = cv2.imdecode(pred_img_array, cv2.IMREAD_COLOR)
prediction_img_encoded = image_to_base64(prediction_img)
plt.close(fig)
except Exception as e:
raise HTTPException(status_code=500, detail=f"Error in OCR model processing: {e}")
# Run Sakshi OCR on the image by saving temporarily
try:
with tempfile.NamedTemporaryFile(delete=False, suffix=".png") as tmp_file:
cv2.imwrite(tmp_file.name, img)
tmp_file_path = tmp_file.name
sakshi_output = run_sakshi_ocr(tmp_file_path)
os.remove(tmp_file_path)
except Exception as e:
sakshi_output = f"Error running Sakshi OCR: {e}"
# Prepare the response
response_data = {
"word_count": word_count,
"ocr_prediction": pred_label,
"sakshi_ocr_output": sakshi_output,
"original_image": original_image,
"word_detected_image": word_img_encoded,
"prediction_image": prediction_img_encoded
}
return JSONResponse(content=response_data)
if __name__ == "__main__":
import uvicorn
uvicorn.run(app, host="0.0.0.0", port=8000)