[GUI Plugin] Hardcover

[sornay]

Hardcover

A Calibre plugin that applies Apple Books-style hardcover effects to your book covers.

Adds realistic 3D spine shadows, spine highlights, page edges, rounded corners, and a subtle background blur to flat cover images.

Features

- Hardcover compositing — spine shadow, spine highlight, page edges, rounded corners, background blur
- RTL support — full right-to-left spine for Arabic, Hebrew, Persian books
- Side-by-side preview — compare original vs generated cover before applying
- Batch processing — generate and apply covers for multiple books at once, with progress bars
- Non-destructive — original covers are backed up and can be restored at any time
- Library filtering — toolbar menu to filter books by generation status
- Keyboard navigation — left/right arrows to browse books in the preview dialog

Requirements

- Calibre 5.0 or newer [not sure]
- Windows, macOS, or Linux

Installation

1. Download hardcover-plugin.zip
2. In Calibre, go to Preferences > Plugins > Load plugin from file
3. Select the zip file and restart Calibre
4. A blue book icon appears in your toolbar

Usage

Single cover

1. Select a book in your library
2. Click the Hardcover toolbar icon
3. Check RTL Spine if the book is right-to-left
4. Click Generate
5. Preview the result, then click Apply

Batch processing

1. Select multiple books in your library
2. Open Hardcover
3. Click Generate All — a progress bar shows status
4. Click Apply All to apply all generated covers

Restoring originals

- Single book: select the book, open Hardcover, click Restore
- Multiple books: click Restore All

Library filters

Right-click the toolbar icon for:
- Show books with generated covers
- Show books without generated covers

Keyboard shortcuts

Left arrow — previous book
Right arrow — next book

How it works

The plugin composites pre-rendered overlay images (spine shadows, highlights, page edges) onto your cover using blend modes that replicate Apple Books' rendering:

1. Resize cover to 600px wide (preserving aspect ratio)
2. Apply rounded-rectangle mask
3. Create blurred background with multiply blend
4. Apply spine-linearburn overlay (multiply blend)
5. Apply spine-normal overlay (alpha composite)
6. Apply spine-softlight overlay (soft-light blend)
7. Apply page edges overlay (alpha composite)

-Completely vibe coded guys, hope you like it as much as I do

[Comfy.n]

Very cool and works fine. The "Show Me" terminology feels unclear to me.

[sornay]

Originally Posted by Comfy.n

Very cool and works fine. The "Show Me" terminology feels unclear to me.

I added this button for times when you generate a cover but forget to apply it. it shows you just the generated covers and let you decide whether apply or not. It might be overkill