Ingest, query, preview, manage and transform images for editing and frontends

Image Service


Image Service is a Mosaic Managed Service. Its purpose is to manage images and transform them into the formats requested by the frontend applications. Images can be uploaded to the Image Service via its GraphQL API or fetched by the Image Service from external storage. Images are assigned an Image Type, interpreted by the frontend applications, and optionally tagged with arbitrary tags.

Once in the Image Service, the images can be requested in any format, defined by:

  • image resolution (width, height)

  • focal point (a center around which to cut an image)

  • image format (JPEG, PNG, WebP).

Using a CDN, it is possible to drastically reduce traffic to the Image Service by storing the transformation results on the edge servers near the customers. Image Service comes with a Micro-Frontend for managing and uploading images. It plugs seamlessly into the Management System where it can be used together with other Mosaic Services. Image Service exposes frontend extensions that any other Mosaic Service can use to select an image and to render an image preview.

Data Model

Image ServiceImagetitleimage typefilenamesource filenamesource file typesource locationfile size (bytes)width, heightImage Typename«file»Image FileServiceTagnameImage Acquisition Profilestorage typelocationroot folderusernamepasswordFigure 1. Image Service Data Model
Figure 1. Image Service Data Model

Image. Image has a file (stored in internal storage) and metadata. Image is immutable. If a change is required, a new image shall be uploaded. This is to prevent unexpected consequences of an image change for existing usages.

Images can be uploaded in a number of ways:

  • Interactively, using a GUI

  • Synchronously, using GraphQL API

  • Asynchronously, from a configured image storage, using Messaging.

Image Type. Every Image shall be assigned to an Image Type. Image Types can be defined by any other service (using Messaging). Image Type has no semantic in the context of the Image Service, but they can be interpreted by the owning service.

Image Tag. Users can tag Images. Other services can give meaning to the tags.


Image Transformation API

Image representations are generated on the fly by applying the necessary transformations. There is no need to define the formats in advance and pre-generate images. To reduce the load on the Image Service we highly recommend using a CDN.

The Image Transformation API provides a single endpoint /transform accessible with an HTTP GET verb.

The request shall be formatted as seen below:$environment-specific-identifier/$filename?parameter=value

The URL parameters are:

Parameter Comment Example Default


contains the tenantId and environmentId




image filename




desired width/height in px


full width/height


desired image format

'jpg', 'png', or 'webp'


focalX, focalY

manual overwrite for the focal point, decimal between 0 and 1


focal point configured in the management system


It is enough to specify either the width or the height of the image. The other dimension will be calculated based on the original aspect ratio. Consider that if asked for the dimensions beyond the size of the original, the service will deliver the original size instead.

To find out the environment-specific-id and filename for a specific image, you can query the GraphQL API. Alternatively, in the Image Service Micro-Frontend you can go to the "Image Detail" station and then to "Focal Point", and then "Copy image address" from either the main image or one of the transformation examples on the right.
Image Focal Point
Figure 2. Image Focal Point

GraphQL Admin API

This API provides read- and management access to all data inside the Image Service.

To use the API you need a JWT from the Admin Service.

Image Upload

GraphQL mutation uploadImage can be used to upload a new image.


  • Image File

  • Image Type.

Altair endpoint - - can be more convenient interface to upload files via GraphQL.


Image Service supports a number of commands and events.

See also: Messaging.

Server-side Download

There is a command initiating image download from a configured image storage.


  • Image relative path in the image storage (e.g. "/images/covers/avatar.jpg")

  • Image type that defines which image formats to create (e.g. "movie_cover").

  • Optionally, a list of tags to add to the image

  • Optionally, a correlation ID.


Ingest feature implemented in the Media Service allows to create and link an image (cover) for each ingested entity downloading them from a pre-configured Image Storage. Ingest uses the interface described above under Server-side Download.


Image Service comes with a Micro-Frontend for managing and uploading images. It plugs seamlessly into the Management System where it can be used together with the other Mosaic Services.

Image Overview
Figure 3. Image Overview
Image Detail
Figure 4. Image Detail

Image Service exposes frontend extensions that any other Mosaic Service can use to render an image preview and to select an image.

Image Preview
Figure 5. Frontend Extension - Image Preview
Select Image
Figure 6. Frontend Extension - Select Image


Management System Settings

Image Service settings in the Management System include an image acquisition profile. You can configure a storage location for image ingest.


The service fee follows the tiered model depending on the number of images. See Mosaic Pricing for more details.