encode_data.py

from PIL import Image
import qrcode
import math

path = "./imginput.jpg"

general_info = f"{path};{path.split('.')[-1]}"
print(general_info)

# Read data
data = open(path, "rb").read()

# --- Create QR codes from chunks ---
chunk_size = 750  # bytes per QR
qr_codes = []
data_chunks = []

total = math.ceil(len(data)/chunk_size)
for i in range(total):
    chunk = data[i*chunk_size:(i+1)*chunk_size]
    chunk_str = chunk.decode("latin-1")
    data_chunks.append(chunk_str)
    payload = f"{i+1}/{total+1}|{chunk_str}"
    qr = qrcode.QRCode(
        version=None,  # automatic
        error_correction=qrcode.constants.ERROR_CORRECT_L,
        box_size=10,
        border=1
    )
    qr.add_data(payload, optimize=0)
    qr.make(fit=True)
    qr_img = qr.make_image(fill_color="black", back_color="white").convert("RGB")
    qr_codes.append(qr_img)

# --- SETTINGS ---
page_width_mm = 210
page_height_mm = 297
dpi = 300  # printing DPI
margin_mm = 1
spacing_mm = 1
images_per_row = 3
images_per_column = 4  # odd for center

def mm_to_px(mm, dpi):
    return int(mm * dpi / 25.4)

page_width_px = mm_to_px(page_width_mm, dpi)
page_height_px = mm_to_px(page_height_mm, dpi)
margin_px = mm_to_px(margin_mm, dpi)
spacing_px = mm_to_px(spacing_mm, dpi)

# Custom center QR code
center_qr = qrcode.QRCode(
    version=None,
    error_correction=qrcode.constants.ERROR_CORRECT_H,
    box_size=10,
    border=2
)

# Center
center_qr.add_data(f"0/{total+1}|" + general_info)
center_qr.make(fit=True)
center_image = center_qr.make_image(fill_color="black", back_color="white").convert("RGB")

# Calculate max size per cell
grid_width_px = page_width_px - 2*margin_px - (images_per_row-1)*spacing_px
grid_height_px = page_height_px - 2*margin_px - (images_per_column-1)*spacing_px
cell_width_px = grid_width_px // images_per_row
cell_height_px = grid_height_px // images_per_column

# Pagination
pages = []
images_per_page = images_per_row * images_per_column - 1  # leave center free
num_pages = math.ceil(len(qr_codes) / images_per_page)

for page_idx in range(num_pages):
    page = Image.new("RGB", (page_width_px, page_height_px), color="white")
    
    start_idx = page_idx * images_per_page
    end_idx = start_idx + images_per_page
    page_images = qr_codes[start_idx:end_idx]
    
    img_counter = 0
    for row in range(images_per_column):
        for col in range(images_per_row):
            # Center cell
            if row == images_per_column//2 and col == images_per_row//2:
                img = center_image
            else:
                if img_counter >= len(page_images):
                    continue
                img = page_images[img_counter]
                img_counter += 1
            
            # Resize to fit cell
            img_ratio = img.width / img.height
            cell_ratio = cell_width_px / cell_height_px
            
            if img_ratio > cell_ratio:
                new_width = cell_width_px
                new_height = int(cell_width_px / img_ratio)
            else:
                new_height = cell_height_px
                new_width = int(cell_height_px * img_ratio)
            
            img_resized = img.resize((new_width, new_height), Image.LANCZOS)
            
            # Position
            x = margin_px + col * (cell_width_px + spacing_px) + (cell_width_px - new_width)//2
            y = margin_px + row * (cell_height_px + spacing_px) + (cell_height_px - new_height)//2
            
            page.paste(img_resized, (x, y))
    
    pages.append(page)

# Show first page for testing
# pages[0].save("./qr_page.png")

# Export to PDF
pages[0].save("qr_pages.png", save_all=True, append_images=pages[1:])
print(f"Generated {num_pages} page(s) with center QR code.")