@md2docx/image

@m2d/image

@m2d/image: Client-side image and SVG rasterization plugin for @m2d/core. Converts Markdown ![alt](url), HTML <img>, and diagram SVGs into DOCX-compatible ImageRun elements in browser environments.

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Features

• Universal Image Resolution: Resolves Markdown ![alt](url), HTML <img>, Base64 data URIs, and SVG elements into OpenXML DrawingML pictures.
• Client-Side Canvas Rasterization: High-fidelity in-browser SVG-to-raster conversion via HTML5 Canvas.
• Configurable Error Policies: Supports "warn", "silent", "throw", and "placeholder" modes on image load or network failures.
• Diagram Code Fallbacks: Automatically transforms failed Mermaid diagrams and raw SVGs into authentic Word code blocks with borders and Consolas styling.
• Collapsible Headings in Word: Injects collapsible H6 headings (Word Heading 5) above fallback code blocks without cluttering standard 1–3 level Tables of Contents.
• IndexedDB & Memory Caching: Lock-free multi-tier caching prevents duplicate image fetches and canvas conversions.

Looking for server-side (Node.js) image resolution? Use @m2d/image-node powered by sharp.

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Installation

This package (@md2docx/image) is an official alias of @m2d/image.

Why does this exist?

We provide this package to offer shorter import paths and improved discoverability. While both packages provide identical functionality, @m2d/image is the primary source of truth.

Which one should I use?

• Use @md2docx/image if you prefer the shorter name or specific branding or ESM Only.
• Use @m2d/image for the most stable long-term reference and standard alignment.

Feature	@m2d/image	@md2docx/image
Source Code	Primary	Proxy
Updates	Immediate	Synchronized (Immediately)
Bundle Size	100%	100% (Zero overhead)
Format	ESM + CJS	ESM Only
Maintenance	Primary	Proxy (inherits)
Security	Primary	Proxy (inherits)

Maintenance & Support

Security: Security audits are performed on the canonical package; this alias inherits all security patches automatically.

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$ pnpm add @m2d/image @m2d/core docx

or

$ npm install @m2d/image @m2d/core docx

or

$ yarn add @m2d/image @m2d/core docx

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Quick Start

import { toDocx } from "@m2d/core";
import { imagePlugin } from "@m2d/image";
import { mermaidPlugin } from "@m2d/mermaid";
import remarkParse from "remark-parse";
import { unified } from "unified";

const markdown = `
# Document With Images

![Architecture Diagram](https://example.com/arch.png)

\`\`\`mermaid
graph TD
  A[Start] --> B[Finish]
\`\`\`
`;

const mdast = unified().use(remarkParse).parse(markdown);

const docxBlob = await toDocx(mdast, {}, {
  plugins: [
    mermaidPlugin(), // Generates SVG nodes
    imagePlugin(),   // Converts images and diagram SVGs to DOCX ImageRuns
  ],
});

Plugin Ordering: When combining with diagram plugins like @m2d/mermaid or HTML plugins like @m2d/html, place imagePlugin() after them in the plugins array.

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Plugin Options

export interface IImagePluginOptions {
  /** Maximum image width in inches (default: 6) */
  maxW?: number;

  /** Maximum image height in inches (default: 8) */
  maxH?: number;

  /** Resolution scaling factor for base64 images (default: 3) */
  scale?: number;

  /** Quality factor (0-1) for lossy image formats (default: 0.92) */
  quality?: number;

  /** Fallback image format to convert unsupported types (default: "png") */
  fallbackImageType?: "png" | "jpg";

  /** Custom placeholder image source (path, URL, or data URL) */
  placeholder?: string;

  /**
   * General image error behavior:
   * - "warn": Emits a styled muted text badge with alt text (default).
   * - "silent": Drops the image node completely.
   * - "throw": Rejects toDocx conversion promise with the underlying Error.
   * - "placeholder": Inserts options.placeholder image.
   */
  errorMode?: "warn" | "silent" | "throw" | "placeholder";

  /**
   * Fallback strategy for failed Mermaid diagrams:
   * - "code": Renders the raw Mermaid code in a formatted Word code block (default).
   * - "warn": Emits a warning badge [Mermaid Diagram Error: ...].
   * - "silent": Drops the node completely.
   */
  mermaidFallback?: "code" | "warn" | "silent";

  /**
   * Fallback strategy for failed non-Mermaid SVGs:
   * - "warn": Emits styled muted text badge (default).
   * - "code": Renders raw SVG XML in a Word code block (`lang: "xml"`).
   * - "silent": Drops the node completely.
   */
  svgFallback?: "warn" | "code" | "silent";

  /**
   * Optional heading added above fallback code blocks (H6 level, maps to Word Heading 5).
   * - true: Injects '###### ⚠️ Diagram Source (Render Fallback)' (default).
   * - false: Omits the heading.
   * - string: Injects custom heading text.
   */
  collapsibleHeading?: boolean | string;

  /** Custom image resolver function */
  imageResolver?: ImageResolver;

  /** Cache configuration or sharing across instances */
  cache?: Record<string, Promise<unknown>>;
  maxAgeMinutes?: number; // default: 10080 (7 days)
}

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Deep Dive Guides

Explore our detailed documentation guides:

• Error Handling & Fallbacks Guide: Comprehensive guide on error modes, collapsible headings, and Word TOC safety.
• Custom Resolvers & Caching Guide: Authenticated image fetching, custom headers, and multi-tier IndexedDB cache configuration.

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License

This library is licensed under the MIT open-source license.

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with by Mayank Kumar Chaudhari