image-post-processor

Image Post Processor

Transforms raw PNG outputs from the image pipeline (any provider — openclawroot relay or official OpenAI, both return gpt-image-style PNGs) into production-ready WebP variants.

Inputs

• projects/{slug}/assets/images/{article-slug}/{custom_id}.png × 4
• workspace/{task_id}/image_prompts.json (for alt_text_seed, filename_seed)

4-step pipeline (per image)

import subprocess
from pathlib import Path

images_dir = Path("projects/{slug}/assets/images/{article-slug}/")
for png_file in images_dir.glob("*.png"):
    slot_id = png_file.stem
    
    # Step 1: Strip EXIF
    subprocess.run(["python", "-m", "scripts.image.exif_stripper", str(png_file)])
    
    # Step 2: WebP convert
    webp_file = png_file.with_suffix(".webp")
    subprocess.run(["python", "-m", "scripts.image.webp_converter",
                    str(png_file), "-o", str(webp_file), "-q", "85"])
    
    # Step 3: Srcset 3 sizes
    is_cover = slot_id == "cover"
    args = ["python", "-m", "scripts.image.srcset_generator",
            str(webp_file), "-o", str(images_dir)]
    if is_cover:
        args.append("--cover")  # uses 480/1024/2048
    subprocess.run(args)
    
    # (Removed 2026-06-10: the old "Step 4: compress to <200KB" --target-kb loop.
    # q85 is the single quality knob now — a hard KB cap on 2K/4K sources just
    # re-compressed them to ~q75 and undid the quality upgrade.)

    # Step 4: SEO filename rename
    article_slug = ws.parent.name  # or from state
    purpose = lookup_purpose_for_slot(slot_id)  # from image_prompts.json
    new_name = subprocess.run(["python", "-m", "scripts.image.image_seo_filename",
                                "--slug", article_slug,
                                "--purpose", purpose,
                                "--ext", ".webp"],
                               capture_output=True, text=True).stdout.strip()
    webp_file.rename(images_dir / new_name)

Output

projects/{slug}/assets/images/{article-slug}/
├── best-fishing-rods-2026-cover.webp        (3840w)
├── best-fishing-rods-2026-cover-480w.webp
├── best-fishing-rods-2026-cover-1024w.webp
├── best-fishing-rods-2026-cover-2048w.webp
├── best-fishing-rods-2026-section-1.webp    (1024w)
├── ... (similar for sections 2, 3)
└── image_meta.json                           (per-image metadata)