Rustybara

Prepress-focused PDF manipulation toolkit for graphic designers and print operators.

Rustybara is the convergence of three standalone prepress CLI tools into a unified Rust library and interactive toolset, built on the same primitives those tools proved in production:

It ships as a library crate (rustybara), a CLI/TUI binary (rbara), and a GPU-accelerated PDF page viewer (rbv).

Features

• Trim print marks — Strip printer marks, slug content, and anything outside the TrimBox from PDF pages.
• Resize to bleed — Expand MediaBox (and CropBox) by a specified bleed margin to prepare files for print production.
• Export to image — Rasterize PDF pages to JPEG, PNG, WebP, or TIFF at any DPI.
• Remap CMYK colors — Substitute specific CMYK values in PDF content streams with tolerance-based matching.
• ICC color management — Feature-gated (color) lcms2 integration for ICC profile loading and color space transforms (RGB, CMYK, Gray).
• Pipeline API — Chain operations fluently: open → trim → resize → remap → save.
• Batch processing — Process entire directories of PDFs from CLI or TUI.
• Interactive TUI — App-style terminal interface for designers who prefer guided workflows over raw CLI flags. Configurable output directory.
• Prepress vocabulary — Every API surface speaks in boxes, bleeds, and DPI — not generic PDF primitives.

Quick Start

As a library

Add to your Cargo.toml:

[dependencies]

rustybara = "0.1"

use rustybara::PdfPipeline;

fn main() -> rustybara::Result<()> {
    // Trim marks, resize to 9pt bleed, save
    PdfPipeline::open("input.pdf")?
        .trim()?
        .resize(9.0)?
        .save_pdf("output.pdf")?;

    Ok(())
}

Rasterize a page

use rustybara::{PdfPipeline, encode::OutputFormat, raster::RenderConfig};

fn main() -> rustybara::Result<()> {
    let pipeline = PdfPipeline::open("input.pdf")?;
    let config = RenderConfig::prepress(); // 300 DPI

    pipeline.save_page_image(0, "page_1.jpg", &OutputFormat::Jpg, &config)?;
    Ok(())
}

CLI

# Trim print marks

rbara trim input.pdf


# Resize to 9pt bleed

rbara resize --bleed 9.0 input.pdf


# Export pages as 300 DPI PNGs

rbara image --format png --dpi 300 input.pdf


# Remap a CMYK color (rich black → 60/40/20/100)

rbara remap-color --from 1.0 1.0 1.0 1.0 --to 0.6 0.4 0.2 1.0 input.pdf

TUI

Launch rbara with no arguments to enter the interactive terminal interface:

rbara

Arrow keys navigate, Enter selects, Esc goes back. Single-letter shortcuts are shown in the footer bar. Press ? for the full keyboard reference.

Architecture

Module Map

rustybara/src/
  lib.rs          — Public re-exports
  pipeline.rs     — PdfPipeline: high-level chaining API
  error.rs        — Unified error type
  geometry/
    rect.rs       — Rect (position + dimensions, PDF coordinate system)
    matrix.rs     — Matrix (2D affine CTM transformations)
  pages/
    boxes.rs      — PageBoxes: TrimBox, MediaBox, BleedBox, CropBox reader
  stream/
    filter.rs     — ContentFilter: CTM-walking content stream filter
    color_ops.rs  — ColorRemap: CMYK→CMYK value substitution in content streams
  raster/
    render.rs     — PageRenderer trait, CpuRenderer (pdfium-render)
    config.rs     — RenderConfig (DPI, annotation toggles)
  encode/
    save.rs       — OutputFormat enum, image encoding (JPG/PNG/WebP/TIFF)
  color/            (feature-gated: "color")
    icc.rs        — ColorSpace, IccProfile (ICC profile loading + detection)
    transform.rs  — ColorTransform, RenderingIntent (lcms2 bridge)

Public API

rustybara is a high-level, prepress-scoped crate. The public API speaks in prepress vocabulary:

// Prepress operations
PdfPipeline::open(path)?
    .trim()?                    // Remove content outside TrimBox
    .resize(bleed_pts)?         // Expand page boxes by bleed margin
    .remap_color(from, to, tolerance)?  // Substitute CMYK values
    .save_pdf(path)?;           // Write the result

// Rasterization
pipeline.render_page(0, &config)?;                          // → DynamicImage
pipeline.save_page_image(0, path, &format, &config)?;       // → file

// Page inspection
let boxes = PageBoxes::read(&doc, page_id)?;
boxes.trim_or_media()           // TrimBox if present, else MediaBox
boxes.bleed_rect(9.0)           // Expand trim by bleed amount

Renderer Trait

Rendering is behind a trait for future GPU backend support:

pub trait PageRenderer {
    fn render(&self, page: &PdfPage, config: &RenderConfig)
        -> Result<DynamicImage>;
}

pub struct CpuRenderer;   // pdfium-render — ships today
// pub struct GpuRenderer; // vello/wgpu — future work

Dependencies

Runtime Requirement — PDFium

The render_page and save_page_image functions require the PDFium shared library at runtime. Place the appropriate binary alongside your executable:

Pre-built binaries: pdfium-binaries

Operations that do not rasterize (trim, resize, save_pdf, page_count, PageBoxes::read) work without PDFium.

rbara — CLI & TUI Binary

rbara is the interactive front-end for rustybara. It provides both a flag-based CLI for scripting and a TUI for guided workflows.

Keyboard Reference (TUI)

UX Model

The TUI follows an app-style keyboard model — arrow keys, Enter, Esc — designed for designers who have never used a terminal before. Vim-style bindings may be layered on as aliases in a future version.

File-first workflow: launch → select file or directory → commands become available. Directories auto-glob *.pdf files.

rbv — PDF Page Viewer

rbv is a minimal GPU-accelerated window for PDF page preview, built on wgpu + winit. It is spawned by rbara on demand and communicates via command-line arguments and exit codes.

rbv <file_path> <page_index> [--dpi <n>]

Status: Not yet implemented. See the roadmap below.

Known Limitations

Roadmap

• ICC color management (color module via lcms2) — v0.1.2
• CMYK→CMYK color remapping in content streams — v0.1.2
• RGB→CMYK conversion (vector graphics + embedded images)
• Spot color detection service
• rbv GPU-accelerated page viewer
• PDF/X validation and preflight reports
• Configurable JPEG quality (--quality flag)
• cargo-dist release pipeline (Linux, Windows, macOS including Apple Silicon)

Contributing

cargo test --workspace

• MSRV is Rust 1.85 (edition 2024). Do not raise this floor without discussion.
• The TrimBox is always the source-of-truth reference box. It is never modified by any operation.
• Public API additions require documentation and at least one integration test.
• The app-style keyboard model is the UX baseline for rbara. Modal bindings are opt-in aliases only.

License

• rustybara (library): LGPL-3.0-only
• rbara and rbv (binaries): GPL-3.0-only

The LGPL license on the library allows downstream tools to link against rustybara without copyleft obligations on their own code, while the binaries remain fully copyleft.

Copyright (c) 2026 Addy Alvarado