stitched-full-page-capture

Stitched Full-Page Capture

Overview

Use settled viewport screenshots instead of trusting one-shot browser fullPage captures. This is especially important for Framer pages and other lazy/scroll-animated sites where the MP4 can look correct while the tall screenshot is mostly blank.

When to use this skill

• When a full-page screenshot of a lazy-loaded, scroll-animated, Framer, WebGL/canvas, or reveal-heavy page comes back blank, gray, white, sparse, or shows only a tiny content strip.
• When a one-shot full-page screenshot disagrees with a working scroll-recording MP4 that shows the page rendering correctly.
• When article evidence or section crops must be cut from a trustworthy full-page image instead of an unreliable native fullPage capture.
• When repairing or regenerating daily UI-inspiration article captures via the bundled stitch_full_page_capture.mjs script against a manifest.json.
• When validating a stitched capture by checking dimensions, blank/gray bands, and agreement with the representative still, MP4, and motion frames.
• Not for pages that already render correctly in a single native fullPage screenshot with no lazy-load, scroll-animation, or reveal issues — a plain one-shot capture is enough there.

Core Workflow

1. Open the real page URL, not a marketplace thumbnail, cover image, remix page, or asset URL.
2. Warm the page by scrolling from top to bottom once so lazy media and reveal sections mount.
3. Return to the top.
4. Scroll downward in viewport-sized or slightly-overlapping steps.
5. Wait about 2 seconds after each scroll stop.
6. Capture the settled viewport.
7. Stitch the viewport captures vertically into one full-page image.
8. Cut section crops from that stitched image, not from the native browser fullPage screenshot.
9. Validate the stitched image against the representative still, MP4, and motion frames.

Reject a full-page candidate when it has blank/gray/white bands, very low visual content, missing lazy-loaded sections, an extremely narrow content column, or obvious disagreement with the scroll video.

Script

For daily UI inspiration articles, use the helper script from this skill directory when available:

node <skills-root>/stitched-full-page-capture/scripts/stitch_full_page_capture.mjs \
  --manifest articles/YYYY-MM-DD-ui-inspiration-capture/manifest.json

The script:

• reads items[].pageUrl, fullPageImage, and sectionImages;
• opens each live page in Playwright Chromium;
• warms lazy content by scrolling once;
• captures settled viewport slices;
• stitches slices into fullPageImage;
• regenerates each existing section crop from the stitched image;
• updates manifest.json with fullPageCaptureMethod: "stitchedViewportScreenshots", viewport, step, segment count, and corrected crop coordinates.

Useful options:

--item 4              # repair only item 4, 1-based
--viewport 1440x1100 # default
--step 950           # default; use less than viewport height for overlap
--wait 2000          # ms to wait after each scroll stop
--quality 3          # ffmpeg JPEG quality, lower is better

Validation

After capture or repair:

• Inspect at least the page that was visibly wrong before.
• Confirm sips -g pixelWidth -g pixelHeight full-page/*.jpg reports expected wide/tall dimensions.
• Confirm the full-page image is not mostly blank and includes lower-page content.
• Confirm section crop coordinates are contiguous and end at the full-page image height.
• Run the project’s normal checks, for example:

git diff --check -- articles/YYYY-MM-DD-ui-inspiration-capture/content.md articles/YYYY-MM-DD-ui-inspiration-capture/manifest.json
node scripts/check-ui-inspiration-duplicates.mjs articles/YYYY-MM-DD-ui-inspiration-capture/manifest.json
for f in articles/YYYY-MM-DD-ui-inspiration-capture/videos/*.mp4; do ffprobe -v error "$f" >/dev/null; done

Notes

• The scroll video is evidence that the page can render during real scrolling, but it is not a substitute for full-page still evidence.
• Native fullPage screenshots can still be saved as comparison candidates, but do not use them as source of truth unless they visually match the stitched capture.
• For daily UI articles, update the manifest and commit only the repaired article assets and metadata.

References

• Upstream source: https://github.com/MengTo/Skills/tree/main/agent-skills/codex/stitched-full-page-capture
• Script: scripts/stitch_full_page_capture.mjs
• Agent config: agents/openai.yaml