utils/data.py

import cv2
import numpy as np


# Data utils
def HWC3(x):
    assert x.dtype == np.uint8
    if x.ndim == 2:
        x = x[:, :, None]
    assert x.ndim == 3
    H, W, C = x.shape
    assert C == 1 or C == 3 or C == 4
    if C == 3:
        return x
    if C == 1:
        return np.concatenate([x, x, x], axis=2)
    if C == 4:
        color = x[:, :, 0:3].astype(np.float32)
        alpha = x[:, :, 3:4].astype(np.float32) / 255.0
        y = color * alpha + 255.0 * (1.0 - alpha)
        y = y.clip(0, 255).astype(np.uint8)
        return y


def resize_image(input_image, resolution):
    H, W, C = input_image.shape
    H = float(H)
    W = float(W)
    k = float(resolution) / min(H, W)
    H *= k
    W *= k
    H = int(np.round(H / 64.0)) * 64
    W = int(np.round(W / 64.0)) * 64
    img = cv2.resize(input_image, (W, H), interpolation=cv2.INTER_LANCZOS4 if k > 1 else cv2.INTER_AREA)
    return img

def apply_color(image, color_map):
    image = cv2.cvtColor(image, cv2.COLOR_RGB2LAB)
    color_map = cv2.cvtColor(color_map, cv2.COLOR_RGB2LAB)

    l, _, _ = cv2.split(image)
    _, a, b = cv2.split(color_map)

    merged = cv2.merge([l, a, b])

    result = cv2.cvtColor(merged, cv2.COLOR_LAB2RGB)
    return result