# Build a justified mosaic collage from uploaded images

The [🤖/image/merge](/docs/robots/image-merge.md) Robot's `mosaic` effect reads the aspect ratio of each input and solves for a justified tile layout that keeps every photo fully visible. In this demo, we composite six photos into a 1920×1200 canvas with a 12-pixel gutter in a singleStep.

Set `shuffle` to `true` to let the Robot reorder inputs before laying out tiles, `border` to widen the gutters, or `seed` to pin the randomness so the same inputs always produce the same layout.

Step 1:

### ![Handle uploads](/_next/static/immutable/media/handling-uploads.36rsz9f-z39wy.svg)Handle uploads

We can handle uploads of your users directly.[Learn more ›](/services/handling-uploads.md)

![space.jpg](https://demos.transloadit.com/a6/dcdc0a3e9f4d4584debb382fb280f3/space.jpg)

[space.jpg](https://demos.transloadit.com/a6/dcdc0a3e9f4d4584debb382fb280f3/space.jpg)

Image – 1.6 MB

1920 × 1080

![desert.jpg](https://demos.transloadit.com/85/528002f2044db085b6165dc3d221b1/desert.jpg)

[desert.jpg](https://demos.transloadit.com/85/528002f2044db085b6165dc3d221b1/desert.jpg)

Image – 1.5 MB

2560 × 2048

![forest.jpg](https://demos.transloadit.com/56/ba7f51c16e416cb45db5a3712caaaa/forest.jpg)

[forest.jpg](https://demos.transloadit.com/56/ba7f51c16e416cb45db5a3712caaaa/forest.jpg)

Image – 5.0 MB

5266 × 3403

![damselfly.jpg](https://demos.transloadit.com/90/b4c097970740878625fec44713a821/damselfly.jpg)

[damselfly.jpg](https://demos.transloadit.com/90/b4c097970740878625fec44713a821/damselfly.jpg)

Image – 4.6 MB

5023 × 3349

![prinsengracht.jpg](https://demos.transloadit.com/fb/769241c85b4ea09554889557dbacdc/prinsengracht.jpg)

[prinsengracht.jpg](https://demos.transloadit.com/fb/769241c85b4ea09554889557dbacdc/prinsengracht.jpg)

Image – 14 MB

5195 × 3457

![chameleon.jpg](https://demos.transloadit.com/86/d7c43e685b42d9a29c2258d76d3a3a/chameleon.jpg)

[chameleon.jpg](https://demos.transloadit.com/86/d7c43e685b42d9a29c2258d76d3a3a/chameleon.jpg)

Image – 8.9 MB

4799 × 3199

```
":original": {
  "robot": "/upload/handle"
}
```

🤖 [/upload/handle](/docs/robots/upload-handle.md)

This bot receives uploads that your users throw at you from browser or apps, or that you throw at us programmatically

Step 2:

### ![Merge several images into one image](/_next/static/immutable/media/image-processing.01ifhto-sjz1y.svg)Merge several images into one image

We can resize, crop, and (auto-)rotate images, or apply watermarks and other effects, and much more.[Learn more ›](/services/image-processing.md)

![chameleon.jpg](https://demos.transloadit.com/e2/c3660e76f74e0f99e78ab495da196d/chameleon.jpg)

[chameleon.jpg](https://demos.transloadit.com/e2/c3660e76f74e0f99e78ab495da196d/chameleon.jpg)

Image – 1.6 MB

1920 × 1200

```
"collage": {
  "use": {
    "steps": [
      ":original"
    ],
    "bundle_steps": true
  },
  "robot": "/image/merge",
  "result": true,
  "background": "#eee5d3",
  "border": 12,
  "effect": "mosaic",
  "format": "jpg",
  "height": 1200,
  "shuffle": true,
  "width": 1920
}
```

🤖 [/image/merge](/docs/robots/image-merge.md)

This bot merges several images into a single spritesheet

Step 3:

### ![Export files to Amazon S3](/_next/static/immutable/media/file-exporting.1zp-mu826z4vh.svg)Export files to Amazon S3

We export to the storage platform of your choice.[Learn more ›](/services/file-exporting.md)

`:original`

* [https://demos.transloadit.com/a6/dcdc0a3e9f4d4584debb382fb280f3/space.jpg⁠](https://demos.transloadit.com/a6/dcdc0a3e9f4d4584debb382fb280f3/space.jpg)
* [https://demos.transloadit.com/85/528002f2044db085b6165dc3d221b1/desert.jpg⁠](https://demos.transloadit.com/85/528002f2044db085b6165dc3d221b1/desert.jpg)
* [https://demos.transloadit.com/56/ba7f51c16e416cb45db5a3712caaaa/forest.jpg⁠](https://demos.transloadit.com/56/ba7f51c16e416cb45db5a3712caaaa/forest.jpg)
* [https://demos.transloadit.com/90/b4c097970740878625fec44713a821/damselfly.jpg⁠](https://demos.transloadit.com/90/b4c097970740878625fec44713a821/damselfly.jpg)
* [https://demos.transloadit.com/fb/769241c85b4ea09554889557dbacdc/prinsengracht.jpg⁠](https://demos.transloadit.com/fb/769241c85b4ea09554889557dbacdc/prinsengracht.jpg)
* [https://demos.transloadit.com/86/d7c43e685b42d9a29c2258d76d3a3a/chameleon.jpg⁠](https://demos.transloadit.com/86/d7c43e685b42d9a29c2258d76d3a3a/chameleon.jpg)

`collage`

* [https://demos.transloadit.com/e2/c3660e76f74e0f99e78ab495da196d/chameleon.jpg⁠](https://demos.transloadit.com/e2/c3660e76f74e0f99e78ab495da196d/chameleon.jpg)

```
"exported": {
  "use": [
    ":original",
    "collage"
  ],
  "robot": "/s3/store",
  "credentials": "demo_s3_credentials",
  "url_prefix": "https://demos.transloadit.com/"
}
```

🤖 [/s3/store](/docs/robots/s3-store.md)

This bot exports encoding results to Amazon S3

## Live Demo. See for yourself

Loading Uppy demo…

This live demo is powered by [Uppy⁠](https://uppy.io), our open source file uploader that you can also use without Transloadit, and [tus⁠](https://tus.io), our open protocol for resumable file uploads that is making uploading more reliable across the world.

## Build this in your own language

```
<!-- This pulls Uppy from our CDN -->
<!-- For smaller self-hosted bundles, install Uppy and plugins manually: -->
<!-- npm i --save @uppy/core @uppy/dashboard @uppy/remote-sources @uppy/transloadit ... -->
<link
  href="https://releases.transloadit.com/uppy/v3.10.0/uppy.min.css"
  rel="stylesheet"
/>
<button id="browse">Select Files</button>
<script type="module">
  import {
    Uppy,
    Dashboard,
    ImageEditor,
    RemoteSources,
    Transloadit,
  } from 'https://releases.transloadit.com/uppy/v3.10.0/uppy.min.mjs'
  const uppy = new Uppy()
    .use(Transloadit, {
      waitForEncoding: true,
      alwaysRunAssembly: true,
      assemblyOptions: {
        params: {
          // It's often better store encoding instructions in your account
          // and use a `template_id` instead of adding these steps inline
          steps: {
            ':original': {
              robot: '/upload/handle',
            },
            collage: {
              use: {
                steps: [':original'],
                bundle_steps: true,
              },
              robot: '/image/merge',
              result: true,
              background: '#eee5d3',
              border: 12,
              effect: 'mosaic',
              format: 'jpg',
              height: 1200,
              shuffle: true,
              width: 1920,
            },
            exported: {
              use: [':original', 'collage'],
              robot: '/s3/store',
              credentials: 'demo_s3_credentials',
              url_prefix: 'https://demos.transloadit.com/',
            },
          },
        },
      },
    })
    .use(Dashboard, { trigger: '#browse' })
    .use(ImageEditor, { target: Dashboard })
    .use(RemoteSources, {
      companionUrl: 'https://api2.transloadit.com/companion',
    })
    .on('complete', ({ transloadit }) => {
      // Due to `waitForEncoding:true` this is fired after encoding is done.
      // Alternatively, set `waitForEncoding` to `false` and provide a `notify_url`
      console.log(transloadit) // Array of Assembly Statuses
      for (const assembly of transloadit) {
        console.log(assembly.results) // Array of all encoding results
      }
    })
    .on('error', (error) => {
      console.error(error)
    })
</script>

```

[Read docs: Browsers](/docs/sdks/uppy.md)

## So many ways to integrate

Transloadit is a service for companies with developers. And there are many ways developers can put Transloadit to good use inside your company to automate media processing.

#### Bulk imports

Add one of our [import Robots](/services/file-importing.md) to acquire and transcode massive media libraries.

#### Handling uploads

We are *the* experts at reliably [handling uploads](/services/handling-uploads.md). We wrote the [protocol⁠](https://tus.io/) for it.

#### Front-end integration

We integrate with web browsers via our next-gen file uploader [Uppy⁠](https://uppy.io/) and SDKs for Android and iOS.

#### Back-end integration

Send us batch jobs in any server language using one of our [SDKs](/docs/sdks.md) or directly interfacing with our [REST API](/docs/api.md).

#### Pingbacks

Configure a [notify\_url](/services/content-delivery.md) to let your server receive transcoding results JSON in the `transloadit` POST field.

#### On-demand

Use our [Smart CDN](/services/file-importing.md) to adapt files on-demand and stream them directly to your users.

[Browsers](/docs/sdks/uppy.md)[TransloaditKit](/docs/sdks/transloaditkit.md)[Ruby SDK](/docs/sdks/ruby-sdk.md)[HTTP REST API](/docs/api.md)[Python SDK](/docs/sdks/python-sdk.md)[PHP SDK](/docs/sdks/php-sdk.md)[Node.js SDK](/docs/sdks/node-sdk.md)[Java SDK](/docs/sdks/java-sdk.md)[Go SDK](/docs/sdks/go-sdk.md)[cURL](/docs/sdks/curl.md)[Convex](/docs/sdks/convex.md)

[Browsers](/docs/sdks/uppy.md)[TransloaditKit](/docs/sdks/transloaditkit.md)[Ruby SDK](/docs/sdks/ruby-sdk.md)[HTTP REST API](/docs/api.md)[Python SDK](/docs/sdks/python-sdk.md)[PHP SDK](/docs/sdks/php-sdk.md)[Node.js SDK](/docs/sdks/node-sdk.md)[Java SDK](/docs/sdks/java-sdk.md)[Go SDK](/docs/sdks/go-sdk.md)[cURL](/docs/sdks/curl.md)[Convex](/docs/sdks/convex.md)

[Browsers](/docs/sdks/uppy.md)[TransloaditKit](/docs/sdks/transloaditkit.md)[Ruby SDK](/docs/sdks/ruby-sdk.md)[HTTP REST API](/docs/api.md)[Python SDK](/docs/sdks/python-sdk.md)[PHP SDK](/docs/sdks/php-sdk.md)[Node.js SDK](/docs/sdks/node-sdk.md)[Java SDK](/docs/sdks/java-sdk.md)[Go SDK](/docs/sdks/go-sdk.md)[cURL](/docs/sdks/curl.md)[Convex](/docs/sdks/convex.md)

## Other cool demos

[![Image processing](/assets/images/services/image-processing.svg?dpl=dpl_2va3YBn22HhLsqATrmvGRCEgnYNE)Image processingAdd a sepia effect to an image](/demos/image-processing/add-sepia-effect-to-an-image.md)[![Image processing](/assets/images/services/image-processing.svg?dpl=dpl_2va3YBn22HhLsqATrmvGRCEgnYNE)Image processingApply a text watermark to images](/demos/image-processing/text-watermarking.md)[![Document processing](/assets/images/services/document-processing.svg?dpl=dpl_2va3YBn22HhLsqATrmvGRCEgnYNE)Document processingAdd a header of footer to a PDF](/demos/document-processing/add-header-or-footer-to-pdf.md)

Try Transloadit

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