Download and solve images from comic-days.com

cd_hack.py

import cv2, json, asyncio, numpy
from urllib.parse import urlparse
from aiohttp import ClientSession

def solve(file: bytes, page: int) -> None:

    np_array = numpy.frombuffer(file, numpy.uint8)
    image = cv2.imdecode(np_array, cv2.IMREAD_COLOR)
    new_image = image.copy()

    height, width, _ = image.shape
    tile_width, tile_height = width // 32 * 8, height // 4
    
    for x in range(4):
        for y in range(4):
            s_x, s_y = x * tile_width, y * tile_height
            d_x, d_y = x * tile_height, y * tile_width
            tile = image[s_y:s_y+tile_height, s_x:s_x+tile_width]
            new_image[d_x:d_x+tile_height, d_y:d_y+tile_width] = tile

    cv2.imwrite(f"{page:02}.jpg", new_image)

async def process_image(session: ClientSession, page: int, url: str) -> None:
    async with session.get(url) as response:
        content = await response.content.read()
        await asyncio.to_thread(solve, content, page)

async def main() -> None:

    futures = []

    with open("HAR.json") as file:
        data = json.load(file)

    async with ClientSession() as session:
        for entry in data['log']['entries']:
            url = entry['request']['url']
            parsed_url = urlparse(url)

            if parsed_url.netloc == "cdn-img.comic-days.com":
                page = parsed_url.path.split('-')[0][-2:]
                futures.append(process_image(session, int(page), url))

        await asyncio.gather(*futures)

if __name__ == "__main__":
    asyncio.run(main())

cd_hack_multiple.py

import cv2, json, asyncio, numpy
from urllib.parse import urlparse
from aiohttp import ClientSession
from pathlib import Path

def solve(file: bytes, page: int):

    np_array = numpy.frombuffer(file, numpy.uint8)
    image = cv2.imdecode(np_array, cv2.IMREAD_COLOR)
    new_image = image.copy()

    height, width, _ = image.shape
    tile_width, tile_height = width // 32 * 8, height // 4
    
    for x in range(4):
        for y in range(4):
            s_x, s_y = x * tile_width, y * tile_height
            d_x, d_y = x * tile_height, y * tile_width
            tile = image[s_y:s_y+tile_height, s_x:s_x+tile_width]
            new_image[d_x:d_x+tile_height, d_y:d_y+tile_width] = tile

    return new_image

async def process_image(session: ClientSession, page: int, url: str, output) -> None:
    async with session.get(url) as response:
        content = await response.content.read()
        output_data = await asyncio.to_thread(solve, content, page)
        cv2.imwrite(f"{output}/{page:04}.jpg", output_data)

async def process_har(session: ClientSession, har: dict, output) -> None:

    futures = []

    Path(output).mkdir(parents=True, exist_ok=True)

    for entry in har['log']['entries']:
        url = entry['request']['url']
        parsed_url = urlparse(url)

        if parsed_url.netloc == "cdn-img.comic-days.com":
            if "link-slot-series" in parsed_url.path: continue
            page = parsed_url.path.split('-')[0][-4:]
            futures.append(process_image(session, int(page), url, output))

    await asyncio.gather(*futures)

async def main() -> None:

    async with ClientSession() as session:

        if (har := Path("HAR.json")).exists():
            text = har.read_text(); data = json.loads(text)
            process_har(session, data, "Output")
        else: 
            futures = []
            for dir in Path.cwd().glob("*.har"):
                text = dir.read_text(); data = json.loads(text)
                futures.append(process_har(session, data, dir.stem))

            await asyncio.gather(*futures)
                    

if __name__ == "__main__":
    asyncio.run(main())

To use:

1. Open chapter you want to download
2. Open developer tools (F12 usually) and go to network tab
3. Reload the page
4. Seek through all the images in chapter
   5.1 (for single) Save HAR data to "HAR.json" file (click gear, then save HAR data, then rename file to HAR.json)
   5.2 (for multiple) Save HAR data to chapter_num.har (click gear, then save HAR data, then type chapter number)
5. Place it along with script in directory where you want to download images
6. Launch the script and wait a few seconds

Works for paid chapters as well since you provide links manually.