linkedin-carousel

LinkedIn Carousel — Babel Fish

Translating a stack of screenshots into a feed-ready document post. The trick isn't the PDF — it's making the padding invisible.

Boundaries

• MAY: read source images, run magick, write PNGs and PDFs to the requested output path.
• MAY NOT: upload to LinkedIn, post on the user's behalf, or modify the source images in place.

Prerequisites

• ImageMagick installed (magick on PATH). Check with which magick.
• Sources are raster images (PNG/JPG). For non-image inputs, ask the user to export first.

Phase 0 — Understand

Entry: User asked for a LinkedIn carousel.

Gather, asking only what's missing:

• Sources: ordered list of image paths (order = page order in the carousel).
• Slug: kebab-case filename for the PDF (e.g. harness-lab-carousel). If the user gives a topic, derive it; otherwise ask.
• Output path: default thoughts/social-media/carousels/<slug>.pdf if the repo has that dir; otherwise ask.
• Aspect preference: portrait (best feed performance), square, or landscape. If the user has no preference, infer from sources in Phase 1.

Exit: Source list, output path, and aspect intent are known.

Phase 1 — Plan

Entry: Inputs gathered.

Reason step-by-step before generating:

1. Run magick identify on each source to get width × height.
2. Pick canvas aspect to minimize padding:
   • User asked for portrait → 1080×1350 (×2 = 2160×2700).
   • User asked for square → 1080×1080 (×2 = 2160×2160).
   • No preference → if the sources cluster around one aspect, pick the median w/h ratio — this minimizes total padding across the deck. If sources span a wide range (e.g. 1.6:1 → 2.6:1), pick the aspect that makes the most pages padding-free, and accept that the outliers will get bands.
3. Sample background color per page — the move that makes seams invisible. Need the dimensions first, then sample three corners:

   read W H < <(magick identify -format "%w %h" "$src")
   magick "$src" -format \
     "tl=%[pixel:p{5,5}] tr=%[pixel:p{$((W-5)),5}] bl=%[pixel:p{5,$((H-5))}]\n" \
     info:
   

   If all three corners agree, use that color. If they disagree, the source has no clean border — fall back to #F4EFE3 (or another neutral the user prefers) and tell them.
4. Render at 2× target resolution with Lanczos resampling. 300 DPI in the final PDF.