Metadata Utilities

Extract and manipulate metadata from NovelAI-generated images.

Extract Metadata

Read generation parameters embedded in NovelAI images:

import { extractMetadata } from 'novelai-sdk-unofficial';
import { readFileSync } from 'fs';

const imageBuffer = readFileSync('novelai-image.png');
const metadata = await extractMetadata(imageBuffer);

console.log(metadata);
// {
//   prompt: '1girl, cat ears',
//   negativePrompt: 'bad anatomy',
//   steps: 28,
//   scale: 5.0,
//   seed: 12345,
//   sampler: 'k_euler_ancestral',
//   ...
// }

Metadata Fields

The ImageMeta type includes:

Field	Type	Description
prompt	string	Generation prompt
negativePrompt	string	Negative prompt
steps	number	Generation steps
scale	number	CFG scale
seed	number	Random seed
sampler	string	Sampler used
width	number	Image width
height	number	Image height
model	string	Model used

Erase Metadata

Remove metadata from images for privacy:

import { eraseMetadata } from 'novelai-sdk-unofficial';
import { readFileSync, writeFileSync } from 'fs';

const imageBuffer = readFileSync('novelai-image.png');

// Erase all metadata
const cleanImage = await eraseMetadata(imageBuffer, 'all');
writeFileSync('clean-image.png', cleanImage);

Erase Targets

Target	Description
'all'	Remove all metadata
'prompt'	Remove only prompt-related data
'stealth'	Remove stealth metadata

// Remove only prompt
const noPrompt = await eraseMetadata(imageBuffer, 'prompt');

// Remove stealth metadata
const noStealth = await eraseMetadata(imageBuffer, 'stealth');

// Remove everything
const clean = await eraseMetadata(imageBuffer, 'all');

Use Cases

Reproduce an Image

const metadata = await extractMetadata(imageBuffer);

// Use extracted parameters to regenerate
const images = await client.image.generate({
  prompt: metadata.prompt,
  negativePrompt: metadata.negativePrompt,
  steps: metadata.steps,
  scale: metadata.scale,
  seed: metadata.seed,
  sampler: metadata.sampler as Sampler,
});

Privacy Before Sharing

async function prepareForSharing(imagePath: string): Promise<Buffer> {
  const image = readFileSync(imagePath);
  return eraseMetadata(image, 'all');
}

const safeImage = await prepareForSharing('my-image.png');
writeFileSync('share-safe.png', safeImage);

Batch Metadata Extraction

import { readdir } from 'fs/promises';
import { join } from 'path';

async function extractAllMetadata(directory: string) {
  const files = await readdir(directory);
  const pngFiles = files.filter(f => f.endsWith('.png'));
  
  const results = [];
  for (const file of pngFiles) {
    const buffer = readFileSync(join(directory, file));
    try {
      const meta = await extractMetadata(buffer);
      results.push({ file, metadata: meta });
    } catch {
      results.push({ file, metadata: null });
    }
  }
  
  return results;
}

Error Handling

try {
  const metadata = await extractMetadata(imageBuffer);
  console.log(metadata);
} catch (error) {
  console.error('Failed to extract metadata:', error.message);
  // Image may not be from NovelAI or metadata may be corrupted
}

Notes

• Only PNG images from NovelAI contain extractable metadata
• JPEG and other formats don't preserve NovelAI metadata
• Some images may have metadata stripped already
• The SDK reads both standard and stealth metadata formats