src/streamlit_app.py

import io
import numpy as np
import streamlit as st
from PIL import Image, ImageFilter, ImageOps

st.set_page_config(page_title="Image → Sketch (Lite)", page_icon="🎨", layout="centered")
st.title("Image → Sketch (Lite) 🎨")
st.caption("PIL + NumPy ile basit kurşun kalem efekti (Gaussian blur + color dodge).")

file = st.file_uploader("Bir görsel yükle (jpg, png, jpeg)", type=["jpg", "png", "jpeg"])
radius = st.slider("Bulanıklık yarıçapı (Gaussian)", 1, 25, 8)

def color_dodge(gray_img: Image.Image, blur_img: Image.Image) -> Image.Image:
    """PIL (L) iki resmi color-dodge ile birleştirir (NumPy ile)."""
    g = np.asarray(gray_img).astype(np.float32)
    b = np.asarray(blur_img).astype(np.float32)
    # 255 - b yaklaştıkça bölme büyür; sıfıra bölmeyi engellemek için epsilon
    eps = 1e-3
    out = np.clip(g * 255.0 / (255.0 - b + eps), 0, 255).astype(np.uint8)
    return Image.fromarray(out, mode="L")

if file:
    img = Image.open(file).convert("RGB")
    gray = img.convert("L")
    inverted = ImageOps.invert(gray)
    blurred = inverted.filter(ImageFilter.GaussianBlur(radius=radius))
    sketch = color_dodge(gray, blurred)

    col1, col2 = st.columns(2)
    with col1:
        st.image(img, caption="Orijinal", use_container_width=True)
    with col2:
        st.image(sketch, caption=f"Sketch (radius={radius})", use_container_width=True, clamp=True)

    # İndir
    buf = io.BytesIO()
    sketch.save(buf, format="PNG")
    st.download_button("PNG olarak indir", data=buf.getvalue(), file_name="sketch.png", mime="image/png")
else:
    st.info("Devam etmek için bir görsel yükle.")