app.py

import streamlit as st
import numpy as np
import cv2
import tempfile
import os
from io import BytesIO
from matplotlib import pyplot as plt

# Load model files
prototxt_path = "colorization_deploy_v2.prototxt"
model_path = "colorization_release_v2.caffemodel"
kernel_path = "pts_in_hull.npy"

# Streamlit app title
st.title("Video Colorization App")

# File upload
uploaded_video = st.file_uploader("Upload a black and white video", type=["mp4", "avi"])

if uploaded_video is not None:
    # Save uploaded video to a temporary file
    tfile = tempfile.NamedTemporaryFile(delete=False)
    tfile.write(uploaded_video.read())
    video_path = tfile.name

    # Output path for the colorized video
    output_path = os.path.join(tempfile.gettempdir(), "colorized_video.mp4")

    # Load the pre-trained model
    net = cv2.dnn.readNetFromCaffe(prototxt_path, model_path)
    points = np.load(kernel_path)
    points = points.transpose().reshape(2, 313, 1, 1)
    net.getLayer(net.getLayerId("class8_ab")).blobs = [points.astype(np.float32)]
    net.getLayer(net.getLayerId("conv8_313_rh")).blobs = [np.full([1, 313], 2.686, dtype="float32")]

    # Open the video file
    cap = cv2.VideoCapture(video_path)

    # Get video properties
    frame_width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
    frame_height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
    fps = cap.get(cv2.CAP_PROP_FPS)

    # Create a VideoWriter object to save the colorized video
    fourcc = cv2.VideoWriter_fourcc(*"mp4v")
    out = cv2.VideoWriter(output_path, fourcc, fps, (frame_width, frame_height))

    frame_count = 0
    stframe = st.empty()  # Placeholder for showing frames in Streamlit

    # Process each frame
    while True:
        ret, frame = cap.read()
        if not ret:
            break

        frame_count += 1
        print(f"Frame: {frame_count}")
        # Convert frame to LAB color space and preprocess
        normalized = frame.astype("float32") / 255.0
        lab = cv2.cvtColor(normalized, cv2.COLOR_BGR2LAB)
        resized = cv2.resize(lab, (224, 224))
        L = cv2.split(resized)[0]
        L -= 50

        # Set the input and get the colorization
        net.setInput(cv2.dnn.blobFromImage(L))
        ab = net.forward()[0, :, :, :].transpose((1, 2, 0))
        ab = cv2.resize(ab, (frame.shape[1], frame.shape[0]))

        # Combine with the L channel
        L = cv2.split(lab)[0]
        colorized = np.concatenate((L[:, :, np.newaxis], ab), axis=2)
        colorized = cv2.cvtColor(colorized, cv2.COLOR_LAB2BGR)
        colorized = (255 * colorized).astype("uint8")

              

        # Write colorized frame to output
        out.write(colorized)

    # Release resources
    cap.release()
    out.release()

    # Provide a download link for the colorized video
    st.success("Video colorization completed!")
    with open(output_path, "rb") as file:
        btn = st.download_button(label="Download Colorized Video", data=file, file_name="colorized_video.mp4", mime="video/mp4")