"""Rebuild the Call for Papers PDF with a real text layer. The two pages stay exactly what they are — full-page renders of an approved design — but the PDF gains an invisible text layer placed over the visible words. The consequences are the point of the exercise: the CFP becomes searchable, indexable by Google, readable by a screen reader, and an author can finally select the deadline or the contact address and paste them somewhere. Nothing here is transcribed from memory. Every string below is read off the rendered pages, and `verify()` extracts the text back out of the finished PDF and checks the facts that matter. python3 fix_cfp_2026_08.py # page 2 repairs → cfp_p2_fixed.png python3 build_cfp_pdf.py # → META2027_Call_for_Papers.pdf """ import fitz from PIL import Image SCALE = 3 # the renders are 3× a 595 × 841 pt page QUALITY = 82 # visually indistinguishable here, and a third of the weight OUT = 'META2027_Call_for_Papers.pdf' LAYER_FONT = 'Sora.ttf' # Unicode-capable; only ever used invisibly # ---------------------------------------------------------------------------- the text layer # (text, x0, y0, x1, y1) in render pixels; y bands measured off the pages. PAGE1 = [ ("17TH INTERNATIONAL CONFERENCE ON METAMATERIALS, PHOTONIC CRYSTALS & PLASMONICS", 90, 340, 1740, 415), ("META 2027", 90, 480, 1200, 612), ("Niagara Falls Convention Centre", 90, 665, 1200, 710), ("Niagara Falls, Ontario, Canada", 90, 730, 1200, 775), ("JULY 13–16, 2027", 90, 806, 1200, 848), ("CALL FOR PAPERS", 130, 1258, 700, 1332), ("META invites original contributions addressing fundamental advances, emerging concepts, " "devices and applications across metamaterials, photonics, plasmonics and structured " "light–matter interactions.", 130, 1376, 1300, 1584), ("TRACK 1 Metamaterials, Metasurfaces & Structured Waves", 130, 1632, 1500, 1670), ("TRACK 2 Plasmonics, Nano-Optics & Light–Matter Interactions", 130, 1710, 1500, 1752), ("TRACK 3 Photonic Crystals, Topological & Quantum Photonics", 130, 1788, 1500, 1832), ("TRACK 4 Emerging Platforms, Design, Fabrication & Applications", 130, 1865, 1500, 1908), ("Call opens September 1, 2026", 130, 2024, 700, 2110), ("Submission deadline February 12, 2027", 700, 2024, 1150, 2110), ("Contributed papers 2 – 4 pages", 1150, 2024, 1620, 2110), ("ISSN 2429-1390", 130, 2225, 600, 2265), ("metaconferences.org", 1330, 2270, 1740, 2310), ] PAGE2 = [ ("META 2027 — CALL FOR PAPERS", 130, 62, 1200, 105), ("Niagara Falls, Canada · July 13–16, 2027", 130, 108, 1200, 145), ("What to submit", 130, 243, 800, 282), ("A contribution of two to four pages, prepared with the official META 2027 template: title, " "authors and affiliations; a short abstract of 50 words at most; motivation and context; " "principal methods and results; figures and references. Submit as PDF. Authors choose the " "length that fits their work. The paper submitted for review is the paper published in the " "proceedings — there is no second, final-paper deadline. Invited contributions: one page " "minimum.", 130, 330, 1740, 565), ("Review criteria", 130, 593, 800, 633), ("Scientific quality — sound methods, analysis and conclusions", 130, 681, 1740, 722), ("Originality — a new result, concept, method or significant advance", 130, 730, 1740, 770), ("Significance — relevance to META’s scope and interest to the community", 130, 779, 1740, 819), ("Clarity — motivation and results presented clearly for technical review", 130, 828, 1740, 868), ("Key dates", 130, 908, 800, 947), ("Call for Papers opens September 1, 2026", 130, 996, 1740, 1041), ("Submission deadline February 12, 2027", 130, 1044, 1740, 1090), ("Acceptance notification February 19, 2027", 130, 1093, 1740, 1138), ("Early registration until April 23, 2027", 130, 1142, 1740, 1189), ("Advanced registration until June 5, 2027", 130, 1191, 1740, 1238), ("Conference July 13–16, 2027", 130, 1240, 1740, 1290), ("General Co-Chairs", 130, 1319, 800, 1360), ("Khaled Mnaymneh National Research Council Canada", 130, 1407, 1740, 1450), ("Sofiane Haffouz National Research Council Canada", 130, 1454, 1740, 1497), ("Said Zouhdi Université Paris-Saclay, France", 130, 1501, 1740, 1545), ("Special sessions", 130, 1580, 800, 1625), ("Researchers are invited to propose Special Sessions on focused or rapidly developing areas " "within the scope of META 2027. Proposals should identify the scientific theme, the " "organizers and prospective contributors.", 130, 1663, 1740, 1804), ("Proceedings", 130, 1827, 800, 1874), ("Accepted contributions presented at META 2027 are published in the META Conference " "Proceedings (ISSN 2429-1390), indexed in Scopus. The paper submitted for review is the " "proceedings contribution: nothing further is uploaded after acceptance.", 130, 1912, 1740, 2050), ("CALL FOR PAPERS SUBMIT YOUR PAPER PAPER TEMPLATE", 130, 2350, 1740, 2400), ("metaconferences.org · contact@metaconferences.org · Proceedings ISSN 2429-1390 " "(Scopus-indexed)", 130, 2440, 1740, 2490), ] # facts the finished file must contain, checked by extracting its text back out MUST_CONTAIN = [ 'September 1, 2026', 'February 12, 2027', 'February 19, 2027', 'April 23, 2027', 'June 5, 2027', 'July 13–16, 2027', '50 words at most', '2 – 4 pages', 'ISSN 2429-1390', 'contact@metaconferences.org', 'Niagara Falls', ] MUST_NOT_CONTAIN = ['about 50 words', 'Autumn 2026', 'Dublin'] def add_page(doc, image_path, blocks): im = Image.open(image_path).convert('RGB') w, h = im.size[0] / SCALE, im.size[1] / SCALE page = doc.new_page(width=w, height=h) jpg = image_path.rsplit('.', 1)[0] + '_q.jpg' im.save(jpg, 'JPEG', quality=QUALITY, optimize=True, progressive=True) page.insert_image(fitz.Rect(0, 0, w, h), filename=jpg) # The layer is invisible, so the face is irrelevant to the eye — but not to the clipboard: # the Base-14 Helvetica turns every en dash into "?", which would corrupt "13 – 16 July 2027" # and "2 – 4 pages" for anyone who copies them. A real Unicode face fixes that. page.insert_font(fontname='cfp', fontfile=LAYER_FONT) for text, x0, y0, x1, y1 in blocks: rect = fitz.Rect(x0 / SCALE, y0 / SCALE, x1 / SCALE, y1 / SCALE) size = 11.0 while size > 3.0: # render_mode 3 = draw nothing; the glyphs are there, only invisible if page.insert_textbox(rect, text, fontname='cfp', fontsize=size, render_mode=3, align=0) >= 0: break size -= 0.5 else: raise SystemExit(f'texte trop long pour son cadre : {text[:60]}…') return page def verify(path): doc = fitz.open(path) text = ' '.join(' '.join(p.get_text().split()) for p in doc) missing = [s for s in MUST_CONTAIN if s not in text] present = [s for s in MUST_NOT_CONTAIN if s in text] print(f' {len(doc)} pages · {len(text)} caractères extractibles') print(' manquant :', missing or 'rien') print(' interdit présent :', present or 'rien') return not missing and not present def main(): doc = fitz.open() add_page(doc, 'cfp_p1.jpg', PAGE1) add_page(doc, 'cfp_p2_fixed.png', PAGE2) doc.set_metadata({ 'title': 'META 2027 — Call for Papers', 'subject': ('17th International Conference on Metamaterials, Photonic Crystals and ' 'Plasmonics. Niagara Falls, Ontario, Canada, July 13–16, 2027.'), 'author': 'META Conferences', 'keywords': ('metamaterials, photonic crystals, plasmonics, metasurfaces, nanophotonics, ' 'quantum photonics, call for papers, META 2027, Niagara Falls'), }) doc.subset_fonts() # the layer font ships as a subset, not the whole face doc.save(OUT, garbage=4, deflate=True, clean=True) doc.close() import os print(f'{OUT} écrit — {os.path.getsize(OUT) / 1024:.0f} Ko') if not verify(OUT): raise SystemExit('vérification du texte échouée') print(' vérification OK') if __name__ == '__main__': main()