manga_translator/detection/default_utils/imgproc.py

"""  
Copyright (c) 2019-present NAVER Corp.
MIT License
"""

# -*- coding: utf-8 -*-
import numpy as np
from skimage import io
import cv2

def loadImage(img_file):
    img = io.imread(img_file)           # RGB order
    if img.shape[0] == 2: img = img[0]
    if len(img.shape) == 2 : img = cv2.cvtColor(img, cv2.COLOR_GRAY2RGB)
    if img.shape[2] == 4:   img = img[:,:,:3]
    img = np.array(img)

    return img

def normalizeMeanVariance(in_img, mean=(0.485, 0.456, 0.406), variance=(0.229, 0.224, 0.225)):
    # should be RGB order
    img = in_img.copy().astype(np.float32)

    img -= np.array([mean[0] * 255.0, mean[1] * 255.0, mean[2] * 255.0], dtype=np.float32)
    img /= np.array([variance[0] * 255.0, variance[1] * 255.0, variance[2] * 255.0], dtype=np.float32)
    return img

def denormalizeMeanVariance(in_img, mean=(0.485, 0.456, 0.406), variance=(0.229, 0.224, 0.225)):
    # should be RGB order
    img = in_img.copy()
    img *= variance
    img += mean
    img *= 255.0
    img = np.clip(img, 0, 255).astype(np.uint8)
    return img

def resize_aspect_ratio(img, square_size, interpolation, mag_ratio=1):
    height, width, channel = img.shape

    # magnify image size
    target_size = mag_ratio * square_size#max(height, width)

    # set original image size
    # if target_size > square_size:
    #     target_size = square_size

    ratio = target_size / max(height, width)    

    target_h, target_w = int(round(height * ratio)), int(round(width * ratio))
    proc = cv2.resize(img, (target_w, target_h), interpolation = interpolation)

    MULT = 256

    # make canvas and paste image
    target_h32, target_w32 = target_h, target_w
    pad_h = 0
    pad_w = 0
    if target_h % MULT != 0:
        pad_h = (MULT - target_h % MULT)
        target_h32 = target_h + pad_h
    if target_w % MULT != 0:
        pad_w = (MULT - target_w % MULT)
        target_w32 = target_w + pad_w
    resized = np.zeros((target_h32, target_w32, channel), dtype=np.uint8)
    resized[0:target_h, 0:target_w, :] = proc
    target_h, target_w = target_h32, target_w32

    size_heatmap = (int(target_w/2), int(target_h/2))

    return resized, ratio, size_heatmap, pad_w, pad_h

def cvt2HeatmapImg(img):
    img = (np.clip(img, 0, 1) * 255).astype(np.uint8)
    img = cv2.applyColorMap(img, cv2.COLORMAP_JET)
    return img