app.py

# app.py  –  2025‑06 update
import os, cv2, time, psutil, shutil, tempfile, zipfile, numpy as np, gradio as gr
from paddleocr import PaddleOCR

# ------------------------------------------------------------------------
# 1. PaddleOCR – latest lightweight v5‑mobile with angle‑cls disabled
# ------------------------------------------------------------------------
ocr = PaddleOCR(
    lang="en",
    det_model_dir="ppocr_v5_det",
    rec_model_dir="ppocr_v5_rec",
    use_angle_cls=False,            # comic bubbles are already horizontal
    show_log=False
)

# ------------------------------------------------------------------------
# 2. Utility helpers
# ------------------------------------------------------------------------
def wait_for_cpu(th=90, interval=3, timeout=30):
    """Pause if CPU is saturated (helps on free‑tier Spaces)."""
    start = time.time()
    while psutil.cpu_percent(interval=1) > th:
        time.sleep(interval)
        if time.time() - start > timeout:
            break

def classify_bg(avg, w=230, b=50, y=100):
    r, g, b_ = avg
    if r >= w and g >= w and b_ >= w:          # white
        return (255, 255, 255)
    if r <= b and g <= b and b_ <= b:          # black
        return (0, 0, 0)
    if r >= y and g >= y and b_ < y:           # yellowish narration box
        return (255, 255, 0)
    return None

def sample_border(img, box, pad=2):
    h, w = img.shape[:2]
    x1, y1, x2, y2 = box
    x1, x2 = max(0, x1 - pad), min(w - 1, x2 + pad)
    y1, y2 = max(0, y1 - pad), min(h - 1, y2 + pad)
    border = np.concatenate([
        img[y1:y1+pad, x1:x2], img[y2-pad:y2, x1:x2],
        img[y1:y2, x1:x1+pad], img[y1:y2, x2-pad:x2]
    ], axis=0)
    return tuple(np.median(border.reshape(-1, 3), axis=0).astype(int))

# ------------------------------------------------------------------------
# 3. Bubble‑mask (simple heuristic: very‑light regions enclosed)
# ------------------------------------------------------------------------
def make_bubble_mask(rgb):
    gray = cv2.cvtColor(rgb, cv2.COLOR_RGB2GRAY)
    # threshold near‑white & narration‑yellow
    _, white = cv2.threshold(gray, 230, 255, cv2.THRESH_BINARY)
    # small morph closing to join dotted edges
    kernel = cv2.getStructuringElement(cv2.MORPH_ELLIPSE, (5,5))
    mask = cv2.morphologyEx(white, cv2.MORPH_CLOSE, kernel, iterations=2)
    return mask // 255   # 0/1

# ------------------------------------------------------------------------
# 4. Detect & clean
# ------------------------------------------------------------------------
def remove_text_in_bubbles(img_path, dst_path):
    bgr = cv2.imread(img_path)
    if bgr is None:  # skip unreadable
        return
    rgb = cv2.cvtColor(bgr, cv2.COLOR_BGR2RGB)
    bubble_mask = make_bubble_mask(rgb)

    results = ocr.ocr(rgb, cls=False)
    if not results or not results[0]:
        cv2.imwrite(dst_path, bgr)
        return

    for line in results[0]:
        box = line[0]
        text, conf = line[1]
        if conf < 0.4 or not text.strip():
            continue

        # bounding box
        xs, ys = zip(*box)
        x1, x2 = int(min(xs)), int(max(xs))
        y1, y2 = int(min(ys)), int(max(ys))

        # skip if box centre is outside bubble mask
        cx, cy = int((x1+x2)/2), int((y1+y2)/2)
        if bubble_mask[cy, cx] == 0:
            continue  # text is not inside a bubble

        # dynamic padding by height
        h_box = y2 - y1
        pad = 2 if h_box <= 30 else 4 if h_box <= 60 else 6
        x1p, y1p = max(0, x1-pad), max(0, y1-pad)
        x2p, y2p = min(rgb.shape[1]-1, x2+pad), min(rgb.shape[0]-1, y2+pad)

        # choose fill colour
        crop = rgb[y1p:y2p, x1p:x2p]
        fill = classify_bg(np.mean(crop.reshape(-1,3), axis=0))
        if fill is None:
            fill = sample_border(rgb, (x1, y1, x2, y2))

        cv2.rectangle(bgr, (x1p, y1p), (x2p, y2p), fill, thickness=-1)

    cv2.imwrite(dst_path, bgr)

# ------------------------------------------------------------------------
# 5. Gradio batch wrapper
# ------------------------------------------------------------------------
def process_folder(files):
    wait_for_cpu()
    out_dir = tempfile.mkdtemp()
    for f in files:
        fname = os.path.basename(f)
        remove_text_in_bubbles(f, os.path.join(out_dir, fname))
    zip_path = shutil.make_archive(out_dir, 'zip', out_dir)
    return zip_path

# ------------------------------------------------------------------------
# 6. Gradio UI
# ------------------------------------------------------------------------
demo = gr.Interface(
    fn=process_folder,
    inputs=gr.File(file_types=[".jpg", ".jpeg", ".png"],
                   label="Upload comic page images",
                   file_count="multiple"),
    outputs=gr.File(label="Download cleaned .zip"),
    title="Comic Bubble Text Cleaner – PP‑OCRv5",
    description=("Removes speech/thought/narration bubble text only, "
                 "leaving outside FX or captions untouched. "
                 "Powered by PaddleOCR PP‑OCRv5‑mobile."),
    concurrency_limit=1
)

if __name__ == "__main__":
    demo.launch()