app.py

import os
import io
import cv2
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from PIL import Image
from math import tau
from concurrent.futures import ThreadPoolExecutor
import gradio as gr

def fourier_transform_drawing(input_image, frames, coefficients, img_size, blur_kernel_size, desired_range, num_points, theta_points):
    # Convert PIL to OpenCV image
    img = cv2.cvtColor(np.array(input_image), cv2.COLOR_RGB2BGR)

    # Resize the image for faster processing
    img = cv2.resize(img, (img_size, img_size), interpolation=cv2.INTER_AREA)

    # Image processing
    imgray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    blurred = cv2.GaussianBlur(imgray, (blur_kernel_size, blur_kernel_size), 0)
    _, thresh = cv2.threshold(blurred, 0, 255, cv2.THRESH_BINARY_INV | cv2.THRESH_OTSU)
    contours, _ = cv2.findContours(thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

    # find the contour with the largest area
    # largest_contour_idx = np.argmax([cv2.contourArea(c) for c in contours])
    # largest_contour = contours[largest_contour_idx]
    
    # Combine all contours
    def combine_all_contours(contours):
        combined_contour = np.array([], dtype=np.int32).reshape(0, 1, 2)
        for contour in contours:
            combined_contour = np.vstack((combined_contour, contour))
        return combined_contour

    combined_contour = combine_all_contours(contours)
    verts = [tuple(coord) for coord in combined_contour.squeeze()]
    xs, ys = np.asarray(list(zip(*verts)))

    # Scale the coordinates
    x_range, y_range = np.max(xs) - np.min(xs), np.max(ys) - np.min(ys)
    scale_x, scale_y = desired_range / x_range, desired_range / y_range
    xs = (xs - np.mean(xs)) * scale_x
    ys = (-ys + np.mean(ys)) * scale_y

    # Compute Fourier coefficients
    t_list = np.linspace(0, tau, len(xs))
    t_values = np.linspace(0, tau, num_points)
    f_precomputed = np.interp(t_values, t_list, xs + 1j * ys)

    def compute_cn(f_exp, n, t_values):
        coef = np.trapz(f_exp * np.exp(-n * t_values * 1j), t_values) / tau
        return coef

    N = coefficients
    indices = [0] + [j for i in range(1, N + 1) for j in (i, -i)]

    # Parallel computation of coefficients
    with ThreadPoolExecutor(max_workers=8) as executor:
        coefs = list(executor.map(lambda n: (compute_cn(f_precomputed, n, t_values), n), indices))

    # Animation setup
    fig, ax = plt.subplots()
    circles = [ax.plot([], [], 'b-')[0] for _ in range(-N, N + 1)]
    circle_lines = [ax.plot([], [], 'g-')[0] for _ in range(-N, N + 1)]
    drawing, = ax.plot([], [], 'r-', linewidth=2)

    ax.set_xlim(-desired_range, desired_range)
    ax.set_ylim(-desired_range, desired_range)
    ax.set_axis_off()
    ax.set_aspect('equal')
    fig.set_size_inches(15, 15)

    draw_x, draw_y = [], []
    theta = np.linspace(0, tau, theta_points)
    coefs_static = [(np.linalg.norm(c), fr) for c, fr in coefs]

    # Animation function
    def animate(i, coefs, time):
        center = (0, 0)
        for idx, (r, fr) in enumerate(coefs_static):
            c_dynamic = coefs[idx][0] * np.exp(1j * (fr * tau * time[i]))
            x, y = center[0] + r * np.cos(theta), center[1] + r * np.sin(theta)
            circle_lines[idx].set_data([center[0], center[0] + np.real(c_dynamic)], [center[1], center[1] + np.imag(c_dynamic)])
            circles[idx].set_data(x, y) 
            center = (center[0] + np.real(c_dynamic), center[1] + np.imag(c_dynamic))
        
        draw_x.append(center[0])
        draw_y.append(center[1])
        drawing.set_data(draw_x[:i+1], draw_y[:i+1])

    # Create and save the animation
    anim = animation.FuncAnimation(fig, animate, frames=frames, interval=5, fargs=(coefs, np.linspace(0, 1, num=frames)))
    output_animation = "output.mp4"
    anim.save(output_animation, fps=15)
    plt.close(fig)
    return output_animation

# Gradio interface setup
interface = gr.Interface(
    fn=fourier_transform_drawing,
    inputs=[
        gr.Image(label="Input Image", sources=['upload'], type="pil"),
        gr.Slider(minimum=5, maximum=500, value=100, label="Number of Frames"),
        gr.Slider(minimum=1, maximum=500, value=50, label="Number of Coefficients"),
        gr.Number(value=224, label="Image Size (px)", precision=0),
        gr.Slider(minimum=3, maximum=11, step=2, value=5, label="Blur Kernel Size (odd number)"),
        gr.Number(value=400, label="Desired Range for Scaling", precision=0),
        gr.Number(value=1000, label="Number of Points for Integration", precision=0),
        gr.Slider(minimum=50, maximum=500, value=80, label="Theta Points for Animation")
    ],
    outputs=gr.Video(),
    title="Fourier Transform Drawing",
    description="Upload an image and generate a Fourier Transform drawing animation.",
    examples=[["Fourier2.jpg", 100, 200, 224, 5, 400, 1000, 80], ["Luffy.png", 100, 100, 224, 5, 400, 1000, 80]]
)

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