initial commit

tests/compare_pdf_icc.py

@@ -0,0 +1,82 @@
+#!/usr/bin/env python3
+"""Compare a real ICCBased PDF through the sandboxed worker at three scales."""
+from pathlib import Path
+from io import BytesIO
+import argparse
+import hashlib
+import json
+import math
+import os
+import subprocess
+from PIL import Image, ImageChops, ImageDraw, ImageStat, ImageCms
+
+ROOT=Path(__file__).resolve().parent.parent
+parser=argparse.ArgumentParser(description=__doc__)
+parser.add_argument("--build-dir",type=Path,default=ROOT/os.environ.get("DOCVIEW_BUILD_DIR","build"))
+parser.add_argument("--output",type=Path,default=ROOT/"tests/results/pdf-icc")
+args=parser.parse_args()
+from pypdf import PdfReader
+BUILD=args.build_dir.resolve()
+CORPUS=ROOT/"tests/fixtures/pdf/extended"
+OUT=args.output.resolve(); OUT.mkdir(parents=True,exist_ok=True)
+manifest=json.loads((CORPUS/"manifest.json").read_text())
+spec=next(item for item in manifest["documents"] if item["file"]=="icc-linear-rgb.pdf")
+source=CORPUS/spec["file"]; before=hashlib.sha256(source.read_bytes()).hexdigest()
+assert before==spec["sha256"]
+profile=(CORPUS/"linear-srgb.icc").read_bytes()
+assert hashlib.sha256(profile).hexdigest()==manifest["color_profile"]["sha256"]
+reader=PdfReader(source)
+color_space=reader.pages[0]["/Resources"]["/ColorSpace"]["/Linear"]
+assert str(color_space[0])=="/ICCBased"
+assert color_space[1].get_object().get_data()==profile
+image=reader.pages[0]["/Resources"]["/XObject"]["/Sample"].get_object()
+assert str(image["/ColorSpace"][0])=="/ICCBased"
+assert image["/ColorSpace"][1].get_object().get_data()==profile
+cms_profile=ImageCms.ImageCmsProfile(BytesIO(profile))
+report={"scope":"Self-authored ICCBased RGB matrix/TRC vector and raster at actual worker render scales; not full ICC/CMYK/printing acceptance",
+    "fixture_sha256_before":before,"profile":manifest["color_profile"],
+    "worker_sha256":hashlib.sha256((BUILD/"docview-pdf-worker").read_bytes()).hexdigest(),
+    "profile_copyright_readback":ImageCms.getProfileCopyright(cms_profile).strip(),
+    "profile_description_readback":ImageCms.getProfileDescription(cms_profile).strip(),
+    "profile_embedded_in_vector_and_image":True,"transport":"production sandboxed PDFWorker, WorkerProcess, FontBroker, tile IPC",
+    "poppler_version":subprocess.run(["/usr/bin/pdftoppm","-v"],capture_output=True,text=True).stderr.splitlines()[0],
+    "sha256":{str(path.relative_to(ROOT)):hashlib.sha256(path.read_bytes()).hexdigest() for path in
+        [BUILD/"pdf-worker-evidence",BUILD/"docview-pdf-worker",BUILD/"libdocview_pdf.a",BUILD/"libdocview_font_broker.a",ROOT/"tests/render_pdf_worker.cpp",ROOT/"tests/compare_pdf_icc.py",ROOT/"tests/fixtures/pdf/icc_generator.py"]},
+    "reference":"Analytic sRGB transfer function of stated linear RGB values; independent Poppler raster; no human-approved golden",
+    "scales":[]}
+overview=[]; success=True
+for scale in [.5,1.,4.]:
+    folder=OUT/("scale-"+str(scale).replace(".","_")); (folder/"pdfium").mkdir(parents=True,exist_ok=True)
+    subprocess.run([str(BUILD/"pdf-worker-evidence"),str(source),str(folder/"pdfium"),str(scale)],check=True)
+    subprocess.run(["/usr/bin/pdftoppm","-singlefile","-cropbox","-r",str(72*scale),"-png",str(source),str(folder/"poppler")],check=True)
+    a=Image.open(folder/"pdfium/page-1.png").convert("RGB"); b=Image.open(folder/"poppler.png").convert("RGB")
+    meta=json.loads((folder/"pdfium/metadata.json").read_text()); assert meta["renderScale"]==scale
+    size=[math.ceil(v*scale) for v in spec["expected"]["page_sizes_pt"][0]]
+    entry={"scale":scale,"dpi":72*scale,"expected_size":size,"pdfium_size":list(a.size),"poppler_size":list(b.size),
+        "dimensions_match_source":list(a.size)==size==list(b.size),"probes":[]}
+    success=success and entry["dimensions_match_source"]
+    for probe in spec["expected"]["icc_probes"]:
+        x,y=probe["point_pt"]; point=(round(x*scale),round((350-y)*scale))
+        actual_a,actual_b=a.getpixel(point),b.getpixel(point)
+        expected=probe["expected_rgb"]; tolerance=spec["expected"]["probe_tolerance_rgb"]
+        check=dict(probe,point_px=point,pdfium_rgb=actual_a,poppler_rgb=actual_b,
+            both_match_analytic_color=all(abs(actual[k]-expected[k])<=tolerance for actual in (actual_a,actual_b) for k in range(3)))
+        entry["probes"].append(check);success=success and check["both_match_analytic_color"]
+    diff=ImageChops.difference(a,b);diff.save(folder/"difference.png")
+    entry["mean_absolute_channel_error"]=sum(ImageStat.Stat(diff).mean)/3
+    entry["icc_midgray_differs_from_device_control"]=all(abs(entry["probes"][6][which][0]-entry["probes"][7][which][0])>40 for which in ("pdfium_rgb","poppler_rgb"))
+    success=success and entry["icc_midgray_differs_from_device_control"]
+    sheet=Image.new("RGB",(1500,350),"#ededed");draw=ImageDraw.Draw(sheet)
+    for col,(name,img) in enumerate([("PDFium / production worker",a),("Poppler / independent",b),("Absolute RGB difference",diff)]):
+        draw.text((col*500+10,12),f"{scale:g}x {name}",fill="black");thumb=img.copy();thumb.thumbnail((488,300))
+        sheet.paste(thumb,(col*500+(500-thumb.width)//2,42))
+    sheet.save(folder/"comparison.png");overview.append(sheet);report["scales"].append(entry)
+report["fixture_sha256_after"]=hashlib.sha256(source.read_bytes()).hexdigest()
+report["original_unchanged"]=report["fixture_sha256_after"]==before;success=success and report["original_unchanged"]
+report["all_source_assertions_pass"]=success
+canvas=Image.new("RGB",(1500,len(overview)*350),"white")
+for i,sheet in enumerate(overview):canvas.paste(sheet,(0,i*350))
+canvas.save(OUT/"overview.png")
+(OUT/"comparison.json").write_text(json.dumps(report,ensure_ascii=False,indent=2)+"\n")
+print(json.dumps({"all_source_assertions_pass":success,"scales":len(report["scales"]),"probe_count":sum(len(x["probes"]) for x in report["scales"]),"original_unchanged":report["original_unchanged"],"profile_copyright":report["profile_copyright_readback"]},indent=2))
+if not success: raise SystemExit(f"ICC source assertion failed; see {OUT / 'comparison.json'}")