Image Metadata

Unstable API 0.7.0 @project-lakechain/image-metadata-extractor

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The image metadata extractor enriches document metadata with specific information about input images, such as their dimensions, dominant color, orientation, EXIF tags, and more. Those metadata can then be later used by subsequent middlewares in the pipeline, or stored in a database.

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📷 Extracting Metadata

To use this middleware, you import it in your CDK stack and instantiate it as part of a pipeline.

import { ImageMetadataExtractor } from '@project-lakechain/image-metadata-extractor';
import { CacheStorage } from '@project-lakechain/core';

class Stack extends cdk.Stack {
  constructor(scope: cdk.Construct, id: string) {
    const cache = new CacheStorage(this, 'Cache');

    // Extracts metadata from images.
    const imageMetadata = new ImageMetadataExtractor.Builder()
      .withScope(this)
      .withIdentifier('ImageMetadata')
      .withCacheStorage(cache)
      .withSource(source) // 👈 Specify a data source
      .build();
  }
}

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📄 Output

The image metadata extraction middleware does not modify or alter source images in any way. It instead enriches the metadata of their document with captured information. Below is an example of metadata captured using this middleware.

💁 Click to expand example

{
  "specversion": "1.0",
  "id": "1780d5de-fd6f-4530-98d7-82ebee85ea39",
  "type": "document-created",
  "time": "2023-10-22T13:19:10.657Z",
  "data": {
      "chainId": "6ebf76e4-f70c-440c-98f9-3e3e7eb34c79",
      "source": {
          "url": "s3://bucket/image.png",
          "type": "image/png",
          "size": 245328,
          "etag": "1243cbd6cf145453c8b5519a2ada4779"
      },
      "document": {
          "url": "s3://bucket/image.png",
          "type": "image/png",
          "size": 245328,
          "etag": "1243cbd6cf145453c8b5519a2ada4779"
      },
      "metadata": {
        "authors": [
          "John Doe"
        ],
        "title": "A winter in San Francisco",
        "properties": {
          "kind": "image",
          "attrs": {
            "width": 1920,
            "height": 1080,
            "exif": {
              "Make": "Canon",
              "Model": "Canon EOS 5D Mark IV"
            }
          }
        }
      },
      "callStack": []
  }
}

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🏗️ Architecture

This middleware runs within a Lambda compute based on the ARM64 architecture, and packages different libraries to extract the metadata of images.

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🏷️ Properties

Supported Inputs

Mime Type	Description
image/gif	GIF image
image/jpeg	JPEG image
image/png	PNG image
image/tiff	TIFF image
image/webp	WebP image
image/avif	AVIF image

Supported Outputs

Mime Type	Description
image/gif	GIF image
image/jpeg	JPEG image
image/png	PNG image
image/tiff	TIFF image
image/webp	WebP image
image/avif	AVIF image

Supported Compute Types

Type	Description
CPU	This middleware only supports CPU compute.

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📖 Examples

• Metadata Extraction Pipeline - Builds a simple metadata extraction pipeline.