Bender – Mosaic Image Protection

Description

Your WordPress images travel as a mosaic. Whoever steals them finds only shuffled tiles.

Bender protects your site’s photos from scrapers, AI training bots, and outright theft, without touching SEO, speed, or the experience of your human visitors.

How it works

On upload (or from the Media Library), Bender automatically generates two derivatives for every image:

  1. Mosaic atlas – the image in full resolution, with an N×N grid permuted and flipped via HMAC-SHA256 Fisher-Yates using a per-image secret key. A single CDN-cacheable file: downloaded as-is, it’s an unreadable puzzle.
  2. Signed low-res – a reduced version with a visible diagonal watermark and IPTC copyright metadata (read by Google Images), used as the <img> source: SEO, social previews, and the no-JavaScript fallback.

The original hi-res URL never appears in the page markup. In the browser, Bender waits for the image to enter the viewport, downloads the atlas, requests the reconstruction map from a REST endpoint protected by a time-limited HMAC token, and reassembles the mosaic on a <canvas> with a blur-up cross-fade.

What it blocks (and what it honestly doesn’t)

  • HTML scrapers / mass bots — blocked: the HTML only contains the watermarked low-res
  • Right-click “Save image” — blocked: the canvas isn’t a file
  • Hi-res hotlinking — blocked: no plain hi-res URL exists
  • Downloading the atlas — useless: permuted, flipped tiles, no map
  • Map enumeration via REST — mitigated: time-limited HMAC token, per-IP rate limiting
  • Screenshots — not blockable, by any technology

That’s why Bender always signs, not just hides: visible watermarking and IPTC metadata make authorship provable even when a copy slips through.

What’s included

This plugin is fully functional as-is, with no locked or restricted features:

  • Automatic protection on upload, unlimited images
  • 6×6 mosaic grid
  • Visible “Bender™” watermark
  • Default IPTC copyright metadata
  • JPEG atlas format
  • Bulk protect/unprotect from the Media Library, with a protection status column and filter

Denser grids, WebP/PNG atlas formats, fully customizable watermark and IPTC text, invisible forensic (LSB) watermarking, and configurable token validity are available in Bender Pro, a separate plugin distributed outside WordPress.org.

Screenshots

Installation

  1. Upload the bender-mosaic-image-protection folder to /wp-content/plugins/, or install directly from the Plugins screen.
  2. Activate the plugin.
  3. Requires PHP 7.4+ with the GD extension (standard on virtually any WordPress hosting).
  4. Go to the Bender menu to adjust served resolution, quality, and watermark/IPTC toggles. New uploads are protected automatically by default.
  5. For existing images: Media Library select images “Protect with Bender” bulk action.

Page caching: align the token validity (24 hours by default) with your page cache duration, so tokens served from cache remain valid.

FAQ

What is Bender and what does it do?

Bender is a WordPress plugin that protects images from theft: it breaks them into an unreadable mosaic for scrapers and bots, shows visitors a live canvas reconstruction, and serves search engines a signed low-res version with a watermark and IPTC copyright metadata.

Does Bender really block downloads of the high-resolution images?

It blocks automated scrapers, hotlinking, and right-click “Save image”, because the HTML never contains a plain hi-res URL. It cannot prevent a screenshot, because no web technology can — that’s why every image is still signed with a watermark and IPTC metadata.

Does Bender slow down the site or hurt SEO?

No — SEO stays intact and actually improves. The low-res version is a real <img> tag with alt text, indexable by Google Images, with IPTC metadata enabling the “Licensable” badge. CSS and JS together weigh about 4 KB with zero dependencies.

What does a visitor without JavaScript see?

The sharp, watermarked low-res version. There’s never a broken image; canvas reconstruction only happens if JavaScript is active.

Does Bender work with page caching?

Yes: align the token validity (24 hours by default) with your page cache duration.

Does Bender require special hosting?

No — only PHP 7.4+ with the GD extension, standard on virtually any WordPress hosting.

Reviews

There are no reviews for this plugin.

Contributors & Developers

“Bender – Mosaic Image Protection” is open source software. The following people have contributed to this plugin.

Contributors

Changelog

0.1.11

  • Added a “Protection” filter to the Media Library (list view), next to the date filter: show only protected or only unprotected images. Handy on large libraries to find what still needs protecting.
  • Fixed protected images shrinking when the theme’s <img> tag carries no width/height attributes. The tag’s only size reference then becomes the low-res file (480px wide) that replaces the original in src, so the image — and the frame around it — collapsed to that width. Bender now carries over the dimensions the tag had before protection, taken from the file it pointed to. The protected image also keeps a max-width of its own, for themes that size images with a child-combinator rule (.slide > img), which no longer matches once the image sits inside the frame.

0.1.10

  • Fixed protected images changing the page layout. The frame that replaces the <img> was a block-level box with its own aspect ratio, so it — not the theme — decided the size: images sized by the theme through CSS rules on the img selector (logos capped to a fixed height, sliders with a minimum height) grew to their full aspect ratio, containers that took their height from the image collapsed or stretched, and margins coming from copied utility classes were applied twice. The frame is now a plain inline-block wrapper with no aspect ratio of its own, and the image inside keeps the width, height and object-fit the theme gave it, so the layout is identical to the same page without the plugin.

0.1.9

  • Fixed the protected frame collapsing to its own aspect ratio instead of the box the theme had set: when the original <img> (or its <picture> wrapper) carried layout classes or inline styles — the common width:100%; height:100%; object-fit:cover inside a fixed-height container used by carousels, cards and hero sections — the frame that replaces it now inherits them, so the image keeps the width and height it had before.
  • Fixed lazy-loading themes and plugins undoing the protection on scroll: data-src/data-srcset (and the other usual lazy-load attributes) were left on the tag, so the lazy loader put the original image URL back into src as soon as the image entered the viewport.

0.1.8

  • Fixed the “Custom themes / page builders” fallback (universal_scan) leaving <picture> elements (responsive images with multiple <source> breakpoints, e.g. carousels/sliders) completely unprotected: the hi-res URLs in the <source> tags bypassed the mosaic entirely, and the generated canvas ignored the width/height intended for that layout. <picture>/<source> are now replaced by the protected frame like a plain <img>, and the frame keeps the original width/height aspect ratio when set.

0.1.7

  • Fixed the “Custom themes / page builders” fallback (universal_scan, added in 0.1.6): when the only protected image on a page was reached exclusively through this fallback, the mosaic viewer script/style were enqueued too late to ever be printed (the fallback rewrites the fully-buffered page, which closes after wp_head/wp_footer already ran), so visitors saw the static low-res <img> with no <canvas> upgrade — the image looked unprotected even though the server-side markup was correct. Assets are now enqueued as soon as the fallback decides to scan the page, before output buffering starts.

0.1.6

  • Added a fallback for custom-coded themes and page builders that print <img> tags outside the_content()/the_post_thumbnail() (e.g. wp_get_attachment_image() called directly, or a raw <img src="..."> in a hand-built gallery/slider): those images were left completely unprotected before, even after marking the attachment as protected. Bender now also scans the fully rendered page and swaps in the protected version for any image it recognizes. New “Custom themes / page builders” setting to disable this if not needed.

0.1.5

  • Fixed 3 strings (the settings page intro and the “what it stops” note) that silently failed to load their bundled translation because the English source used a straight apostrophe (‘) while the .po files had a typographic one (’). All 6 bundled languages regenerated.

0.1.4

  • Bundled ready-made translations (Italian, Spanish, French, German, Brazilian Portuguese, Chinese Simplified) in languages/, loaded automatically via load_plugin_textdomain() — no need to wait for community translations on translate.wordpress.org.

0.1.3

  • All admin-facing strings (settings page, Media Library column, row/bulk actions, admin notices, error messages) are now proper English source strings wrapped for translation with the bender-mosaic-image-protection text domain, instead of hardcoded Italian. Translators can now localize the plugin via translate.wordpress.org.

0.1.2

  • The fixed values of this edition (6×6 grid, watermark text/opacity, IPTC copyright/credit, 24h REST token TTL) are no longer implemented through generically-parameterized helper functions called with constant arguments. Each is now hardcoded directly inside the function that uses it (no unused $n/$opacity/$ttl-style parameters left over), so the free codebase itself contains no latent/dormant configurability for these values.

0.1.1

  • All function, class, define, and option/transient names now use the bendmoim/BENDMOIM prefix (was bender/Bender, with one stray pg_rl_ transient key).
  • Removed dormant Pro-only code paths from the free codebase (variable grid size, WebP/PNG atlas formats, customizable watermark/IPTC text, LSB steganographic watermark, configurable token TTL) instead of merely locking them via options. This edition now hardcodes the free-tier values described in the plugin’s own settings screen.

0.1.0

  • Initial release.