Image to PDF

Combine multiple image screenshots (typically exam paper questions) into a well-formatted, paginated A4 PDF that is ready for printing.

When to Use

Trigger this skill when the user wants to:

• Combine / merge / stitch images into a PDF
• Put screenshots together into a printable document
• Create a PDF from exam paper photos or screenshots
• Pack question images onto A4 pages for printing

Look for phrases like: "拼到一起", "合成PDF", "拼接", "打印", "combine images", "merge into PDF", etc.

How to Use

This skill includes a Python script at scripts/combine.py (relative to this SKILL.md).

Step 1: Identify inputs and output

From the user's request, extract:

• Input: a directory path or list of image file paths
• Output: the desired PDF output path (default: output.pdf in the input directory)

Step 2: Run the script

Use uv run to handle dependencies automatically (no manual install needed):

uv run --with Pillow --with numpy python3 <path-to-this-skill>/scripts/combine.py <input> -o <output.pdf>

Input formats:

• A directory: python scripts/combine.py ./my_images/ -o result.pdf
• Multiple files: python scripts/combine.py img1.png img2.png -o result.pdf

Optional flags:

• --margin <px>: page margin in pixels at 300dpi (default: 80, ~7mm)
• --no-trim: disable automatic whitespace border trimming
• --dpi <n>: output DPI (default: 300)

Step 4: Report result

Tell the user:

• How many images were processed
• How many PDF pages were generated
• The output file path

What the Script Does

1. Loads images, auto-trims whitespace borders
2. Scales all images to the same width (A4 printable width)
3. Greedily packs images onto A4 pages (tight layout, no gaps)
4. When a page break is needed, uses pixel analysis to find whitespace rows so text is never cut
5. Outputs a 300 DPI PDF ready for printing