image_utils.py

import base64
import numpy as np
from PIL import Image
from io import BytesIO

def load_captured_image(b64_string):
    if not b64_string or not b64_string.startswith("data:image/png;base64,"): return None
    img_data = base64.b64decode(b64_string.split(',')[1])
    return Image.open(BytesIO(img_data)).convert("RGB")

def hex_to_rgb(hex_color):
    try:
        hex_color = hex_color.lstrip('#')
        return tuple(int(hex_color[i:i+2], 16) for i in (0, 2, 4))
    except (ValueError, TypeError, AttributeError):
        return (0, 0, 0)

def process_fade_with_drop(source_image, preserve_hex, falloff_str, drop_hex, drop_strength_str, min_fade_str, recolor_hex, recolor_strength_str):
    if source_image is None: return None
    source_array = np.array(source_image, dtype=np.float32)
    preserve_rgb = np.array(hex_to_rgb(preserve_hex), dtype=np.float32)
    drop_rgb = np.array(hex_to_rgb(drop_hex), dtype=np.float32)
    recolor_rgb = np.array(hex_to_rgb(recolor_hex), dtype=np.float32)
    falloff = float(falloff_str) if float(falloff_str) > 0 else 1
    drop_strength = float(drop_strength_str)
    min_fade_ratio = float(min_fade_str) / 100.0
    recolor_strength = float(recolor_strength_str) / 100.0
    dist_to_preserve = np.linalg.norm(source_array - preserve_rgb, axis=2)
    base_alpha = np.clip(dist_to_preserve / falloff, 0.0, 1.0)
    dist_to_drop = np.linalg.norm(source_array - drop_rgb, axis=2)
    repulsion_influence = 1.0 - np.clip(dist_to_drop / 100.0, 0.0, 1.0)
    repulsion_multiplier = 1.0 + (repulsion_influence * drop_strength)
    final_alpha = np.clip(base_alpha * repulsion_multiplier, 0.0, 1.0)
    final_alpha = np.maximum(final_alpha, min_fade_ratio)
    alpha_reshaped = final_alpha[:, :, np.newaxis]
    white_bg = np.full_like(source_array, 255)
    faded_array = source_array * (1 - alpha_reshaped) + white_bg * alpha_reshaped
    if recolor_strength > 0:
        recolor_mask = final_alpha < 1.0
        pixels_to_recolor = faded_array[recolor_mask]
        recolored_pixels = pixels_to_recolor * (1 - recolor_strength) + recolor_rgb * recolor_strength
        faded_array[recolor_mask] = recolored_pixels
    final_image_array = np.clip(faded_array, 0, 255).astype(np.uint8)
    return Image.fromarray(final_image_array)