imposer

A command-line tool for imposing PDF files into booklet format. It reorders pages so that when printed double-sided and folded, they create a properly ordered booklet.

Installation

Via go install

go install github.com/cosmix/imposer/cmd/impose@latest

Build from source

git clone https://github.com/cosmix/imposer.git
cd imposer
go build ./cmd/impose

Usage

# Using flags
impose -i input.pdf -o output.pdf

# Using positional arguments
impose input.pdf output.pdf

How It Works

The tool performs the following operations:

1. Reads the input PDF file
2. Calculates the correct page order for booklet printing
3. Reorders pages so that when printed double-sided and folded:
   • Pages appear in the correct reading order
   • The total page count is padded to a multiple of 4 if needed
   • Pages are arranged in printer spreads (last-first, first-last pattern)

Example

For an 8-page document, pages will be arranged as:

• Sheet 1 front: Page 8 | Page 1
• Sheet 1 back: Page 2 | Page 7
• Sheet 2 front: Page 6 | Page 3
• Sheet 2 back: Page 4 | Page 5

When printed double-sided, folded in half, and stacked, the pages will read in order from 1 to 8.

License

MIT License - see LICENSE for details