Erimil (選り見る)

A macOS application for visual preview and selective extraction of images from ZIP archives.

Features

• Visual Preview: Browse images inside ZIP files and PDFs without extracting
• Selective Extraction: Mark images to keep or exclude, then generate optimized ZIP
• Folder Support: Also works with regular image folders
• Keyboard-Driven: Navigate and select with keyboard shortcuts
• Favorites System: Mark important images with ★ for protection
• Bookmarks (栞): Named position markers for quick navigation within sources
• Slide Mode: Fullscreen viewing with Favorites Mode for quick navigation
• Spread View: Two-page display for books with RTL support
• PDF Support: View PDF documents page by page

Requirements

• macOS 14.0 (Sonoma) or later

Installation

Download the latest release from GitHub Releases.

Usage

Basic Workflow

1. Drag a folder containing ZIPs to the sidebar, or use File → Open
2. Click a ZIP file to view thumbnails
3. Select images to exclude (or keep, depending on mode)
4. Click "確定 → _opt.zip" to generate optimized archive

Selection Modes

Mode	Click/X Key	Result
Exclude Mode	Mark for removal	Selected items excluded from output
Keep Mode	Mark for keeping	Only selected items included in output

Toggle mode via the toolbar button or Settings.

Keyboard Shortcuts

Common Navigation (All Viewer Modes)

All navigation keys are RTL-aware - they follow "physical key position = visual screen position" principle.

Key	Action
← → ↑ ↓ / WASD	Navigate images
Z / C	Previous / Next favorite ★
Ctrl+A / Ctrl+D	Jump to first / last image
Ctrl+Z / Ctrl+C	Jump to first / last favorite
Cmd+1/2/3/4/5	Jump to 0% / 25% / 50% / 75% / 100%
Ctrl+R	Toggle reading direction (LTR ↔ RTL)
Shift+S	Add / delete bookmark (栞)
Shift+A / Shift+D	Previous / Next bookmark
Shift+B	Bookmark list overlay

Filer View (Thumbnail Grid)

Key	Action
X	Toggle selection
F	Toggle favorite ★
V	Toggle single page marker
Space	Open Quick Look preview
Enter / R	Open Viewer Mode
Ctrl+F	Open Slide Mode
Ctrl+W/S or Ctrl+↑/↓	Previous / Next source

Quick Look Preview

Key	Action
F	Switch to Slide Mode
V	Toggle single page marker
Q / Space / Esc / Enter	Close preview

Viewer Mode

Key	Action
X	Toggle selection
F	Toggle favorite ★
V	Toggle single page marker
T	Cycle thumbnail position
Enter	Open Slide Mode
Q / R / Esc	Close (return to Filer)
Ctrl+W/S or Ctrl+↑/↓	Previous / Next source

Slide Mode (Fullscreen)

Key	Normal Mode	Favorites Mode
← → ↑ ↓ / WASD	Previous/Next image	Previous/Next ★
Z / C	Previous/Next ★	Previous/Next ★
Tab	Next ★ + Enter Favorites Mode	Next ★
F	Toggle favorite ★	Toggle favorite ★
X	Toggle selection	Toggle selection
V	Toggle single page marker	Toggle single page marker
Q	Exit fullscreen	Exit Favorites Mode
Esc	Exit fullscreen	Exit fullscreen
Ctrl+W/S or Ctrl+↑/↓	Previous/Next source	Same
Ctrl+T	Cycle thumbnail position	Same
Shift+S	Add/delete bookmark (栞)	Same
Shift+A / Shift+D	Previous/Next bookmark	Same
Shift+B	Bookmark list overlay	Same
Space	Toggle controls	Toggle controls

Sidebar Navigation

Action	Result
Single-click	Select source, show thumbnails
Double-click	Select source + open Slide Mode

Slide Mode Features

Slide Mode provides fullscreen image viewing with powerful navigation:

Position Indicators

• Image position bar: Shows current position with ★ (favorites) and × (selections) markers
• Source position bar: Shows position among sibling ZIPs/folders/PDFs in the same directory

Favorites Mode

• Press Tab to enter Favorites Mode and jump to the next favorite
• ←/→ or A/D navigate between favorites only (skipping non-favorites)
• Yellow header indicates Favorites Mode is active
• Press Q to exit Favorites Mode (return to normal navigation)

Source Navigation

• Ctrl+W/S or Ctrl+↑/↓ to switch between ZIPs/folders/PDFs
• Maintains fullscreen state during navigation
• Loops from last to first (and vice versa)

Position Jump

• Ctrl+A/D to jump to first/last image
• Ctrl+Z/C to jump to first/last favorite
• Cmd+1-5 to jump to percentage positions (0%/25%/50%/75%/100%)
• All jumps are RTL-aware (physical key = visual position)

Spread View (Two-Page Display)

• Enable in Settings to display two pages side-by-side
• Ideal for book reading
• RTL (right-to-left) direction support for Japanese vertical text
• Wide images automatically displayed as single pages
• Press V to manually mark/unmark pages as single

Favorites System

Erimil uses a Hybrid Favorites design that tracks favorites in two ways:

★ Direct Favorite (Yellow Star)

Favorited in the current source (ZIP/folder). These are protected from deletion in Exclude mode.

When you press F on an image:

• The image is marked as ★ (direct favorite)
• It cannot be selected for exclusion
• Shows "PROTECTED" label in Exclude mode

☆ Inherited Favorite (White Star)

The same image content was favorited in another source. This is a reference only.

Scenario	Display	Protected?
Favorited in this ZIP	★ (yellow)	Yes
Same image favorited elsewhere	☆ (white)	No
Not favorited	(none)	No

Distillation Workflow

This design enables a powerful "distillation" workflow:

photos.zip (100 images)
    ↓ Mark favorites with ★
    ↓ Export
photos_opt.zip (50 images)
    ↓ Open - ☆ shows previous favorites
    ↓ Mark new ★ for best selection
    ↓ Export  
photos_opt_opt.zip (20 images) = Best Selection

Each pass refines your selection, with ☆ showing what you liked before.

Bookmarks (栞) System

Bookmarks are named position markers within a source, allowing quick navigation to important pages.

• Shift+S: Add a bookmark at current position (with custom name) or delete existing bookmark
• Shift+A/D: Navigate between bookmarks (wraps around, RTL-aware)
• Shift+B: Open bookmark list overlay for browsing and jumping
• Grid View: Bookmark dividers appear as section headers between thumbnails

Bookmarks are stored per-source and persist across sessions. Mnemonic: Shift = Shiori (栞).

Data Storage

Erimil stores cache and favorites in the sandboxed container:

~/Library/Containers/jp.pocketstudio.zem.Erimil/Data/Library/Application Support/Erimil/
├── cache/                      # Thumbnail cache (disk)
├── index.json                  # Path hash → content hash mapping
├── favorites_hybrid.json       # Favorites data (hybrid system)
├── bookmarks.json              # Per-source bookmarks (栞)
└── last_folder_bookmark.data   # Security-scoped bookmark for folder restoration

Contributing

Contributions are welcome! This project was created as a practical solution to a real problem, and maintained as a learning resource.

Development Philosophy

• Simplicity First: Resist feature creep
• Privacy Matters: No telemetry, no cloud
• Readable Code: Clear over clever
• User Agency: Give users control

Development Process & AI Usage

This project was developed with assistance from Claude AI (Anthropic). I want to be transparent about this approach and my reasoning.

Standing on the Shoulders of Giants

I've been fortunate to work with open source technologies for over 30 years—from the early internet days to Linux, Virtualization, Cloud Computing, Docker, and beyond. The knowledge and code shared freely by countless developers made my career possible. Using AI trained on open source code without acknowledgment would feel like forgetting where I came from.

Learning, Not Replacing

I used AI as a learning accelerator to explore SwiftUI, a framework I hadn't worked with before:

• I identified the problem (visual preview and selective extraction of images from ZIP archives)
• I defined all requirements and architectural decisions
• AI generated initial code structures and API examples
• I read and understood every line of generated code
• I debugged, refined, and made all final decisions

This mirrors how I learned in the 1990s: reading others' code, asking questions in forums, and building on shared knowledge. The tools changed, but the learning process remains the same.

Why Share This?

I'm sharing this development approach for a few reasons:

Transparency: The community deserves to know how projects are built, especially when new tools are involved.

For students: If you're learning to code, know that using AI as a learning tool is okay—as long as you understand what you're building. Don't copy-paste. Read, understand, modify, and make it yours.

For fellow developers: I don't claim this is the "right" way. It's simply my way of balancing learning new technologies with years of experience in software development. Your approach may differ, and that's perfectly valid.

A Note of Respect

To developers who built their skills entirely through manual effort: I deeply respect that path. This isn't about claiming my approach is superior—it's about being honest regarding the tools I used. The open source community thrives on honesty, sharing, and mutual respect. I hope this project reflects those values, even if the development process looks different from what came before.

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Acknowledgments

This project stands on the shoulders of giants and wouldn't exist without:

Development Support

• ZIPFoundation for reliable ZIP archive handling
• The macOS developer community for comprehensive documentation and helpful discussions
• Apple's engineering teams for SwiftUI and the macOS sandbox security model

Related Tools

• kurumil - Companion tool for image compression and AI upscaling

License

MIT License

Author

Masahito Zembutsu / @zembutsu