BGR2Gray_app.py

import streamlit as st
import cv2
import numpy as np
from PIL import Image
import io

st.set_page_config(page_title="Grayscale Converter", page_icon="🖤", layout="wide")
st.set_page_config(page_title="Grayscale Image Converter", layout="wide")
st.title("🖼️ Grayscale Image Converter")

# 1. Upload the image
uploaded_file = st.file_uploader("Upload an image", type=["jpg", "jpeg", "png"])

if uploaded_file is not None:
    # 2. Load the image using PIL, then convert to OpenCV format
    image = Image.open(uploaded_file)
    img_rgb = np.array(image.convert("RGB"))  # Convert to RGB
    img_bgr = cv2.cvtColor(img_rgb, cv2.COLOR_RGB2BGR)  # Convert to BGR for OpenCV

    # 3. Convert to grayscale
    gray = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2GRAY)

    # 4. Display side-by-side images using columns
    col1, col2 = st.columns(2)

    with col1:
        st.subheader("Original Image")
        st.image(image, use_container_width=True)

    with col2:
        st.subheader("Grayscale Image")
        st.image(gray, use_container_width=True, clamp=True, channels="GRAY")

    # 5. Download option
    st.markdown("---")
    st.subheader("💾 Download Grayscale Image")
    filename = st.text_input(
        "Enter filename (without extension)", value="grayscale_image"
    )

    if filename:
        # Convert grayscale image to PIL and then to byte stream
        gray_image_pil = Image.fromarray(gray)
        buf = io.BytesIO()
        gray_image_pil.save(buf, format="PNG")
        byte_im = buf.getvalue()

        st.download_button(
            label="Download as PNG",
            data=byte_im,
            file_name=filename + ".png",
            mime="image/png",
        )