app.py

import numpy as np
import matplotlib.pyplot as plt
from skimage.color import rgb2gray
from skimage.transform import resize
from skimage.draw import line
from skimage.filters import gaussian
import gradio as gr
import tempfile

def adjust_brightness_contrast(img, brightness=0.0, contrast=1.0):
    img = img * contrast + brightness
    img = np.clip(img, 0, 1)
    return img

def preprocess_image(image, size=(200, 200), brightness=0.0, contrast=1.0):
    if image.ndim == 3:
        img_gray = rgb2gray(image)
    else:
        img_gray = image
    img_resized = resize(img_gray, size, anti_aliasing=True)
    img_adj = adjust_brightness_contrast(img_resized, brightness, contrast)
    img_inverted = 1 - img_adj  # black = 1, white = 0
    img_inverted = (img_inverted - img_inverted.min()) / (img_inverted.max() - img_inverted.min() + 1e-8)
    return img_inverted

def generate_pins(num_pins, radius=1.0):
    angles = np.linspace(0, 2 * np.pi, num_pins, endpoint=False)
    pins = np.array([(radius * np.cos(a), radius * np.sin(a)) for a in angles])
    return pins

def draw_line(canvas, pin1, pin2, opacity=0.2):
    h, w = canvas.shape
    x1 = int((pin1[0] + 1) / 2 * (w - 1))
    y1 = int((pin1[1] + 1) / 2 * (h - 1))
    x2 = int((pin2[0] + 1) / 2 * (w - 1))
    y2 = int((pin2[1] + 1) / 2 * (h - 1))
    rr, cc = line(y1, x1, y2, x2)
    rr = np.clip(rr, 0, h-1)
    cc = np.clip(cc, 0, w-1)
    canvas[rr, cc] = np.clip(canvas[rr, cc] - opacity, 0, 1)
    return canvas

def blur_and_downsample(img, sigma=1.5, size=(100, 100)):
    img_blur = gaussian(img, sigma=sigma)
    img_small = resize(img_blur, size, anti_aliasing=True)
    return img_small

def generate_connections(img, pins, num_connections, opacity=0.2):
    num_pins = len(pins)
    connections = []
    current_pin = 0
    canvas = np.ones_like(img)
    target_blur = blur_and_downsample(img)
    for _ in range(num_connections):
        best_error = np.inf
        best_pin = None
        best_rr, best_cc = None, None
        for next_pin in range(num_pins):
            if next_pin == current_pin:
                continue
            h, w = canvas.shape
            x1 = int((pins[current_pin][0] + 1) / 2 * (w - 1))
            y1 = int((pins[current_pin][1] + 1) / 2 * (h - 1))
            x2 = int((pins[next_pin][0] + 1) / 2 * (w - 1))
            y2 = int((pins[next_pin][1] + 1) / 2 * (h - 1))
            rr, cc = line(y1, x1, y2, x2)
            rr = np.clip(rr, 0, h-1)
            cc = np.clip(cc, 0, w-1)
            temp_canvas = canvas.copy()
            temp_canvas[rr, cc] = np.clip(temp_canvas[rr, cc] - opacity, 0, 1)
            temp_blur = blur_and_downsample(temp_canvas)
            error = np.sum((temp_blur - target_blur) ** 2)
            if error < best_error:
                best_error = error
                best_pin = next_pin
                best_rr, best_cc = rr, cc
        if best_pin is None:
            break
        connections.append((current_pin, best_pin))
        canvas[best_rr, best_cc] = np.clip(canvas[best_rr, best_cc] - opacity, 0, 1)
        current_pin = best_pin
    return connections

def draw_string_art(image, num_pins, num_connections, opacity=0.2, brightness=0.0, contrast=1.0):
    img = preprocess_image(image, brightness=brightness, contrast=contrast)
    pins = generate_pins(num_pins)
    connections = generate_connections(img, pins, num_connections, opacity)
    fig, ax = plt.subplots(figsize=(8, 8))
    ax.set_facecolor("white")
    ax.axis("off")
    for c in connections:
        p1, p2 = pins[c[0]], pins[c[1]]
        ax.plot([p1[0], p2[0]], [p1[1], p2[1]], 'k-', linewidth=0.7, alpha=opacity)
    ax.scatter(pins[:,0], pins[:,1], c='red', s=16)
    plt.tight_layout(pad=0)
    plt.close(fig)
    connections_1_based = [str(c[0]+1) for c in connections]
    connections_str = ', '.join(connections_1_based)
    temp_file = tempfile.NamedTemporaryFile(delete=False, suffix=".txt", mode="w", encoding="utf-8")
    temp_file.write(connections_str)
    temp_file.close()
    return fig, temp_file.name

def interface(image, num_pins, num_connections, opacity, brightness, contrast):
    fig, filename = draw_string_art(image, num_pins, num_connections, opacity, brightness, contrast)
    return fig, filename

demo = gr.Interface(
    fn=interface,
    inputs=[
        gr.Image(type="numpy", label="Upload Image"),
        gr.Slider(50, 400, 100, step=1, label="Number of Pins"),
        gr.Slider(500, 10000, 1000, step=1, label="Number of Connections"),
        gr.Slider(0.05, 0.5, 0.2, step=0.01, label="String Opacity (Lower = Lighter)"),
        gr.Slider(-0.5, 0.5, 0.0, step=0.01, label="Brightness"),
        gr.Slider(0.5, 2.0, 1.0, step=0.01, label="Contrast")
    ],
    outputs=[
        gr.Plot(label="String Art"),
        gr.File(label="Connections File")
    ],
    title="String Art Generator (Wow!Strings-like)",
    description="Upload an image, set the number of pins, connections, string opacity, brightness, and contrast. The generator will create a string art image that closely resembles your input and a downloadable connection file."
)

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