ExdTech.ImageServer

This is the image server used by Exd Pic. It is live at images.exdpic.com. It is a simple image server that uses a REST API. It is designed to be easy to extend and configure.

Functions

High quality image resizing and compression.
Throws Bad Request if non-images are uploaded or if limits on accepted filesize or dimensions are exceeded.
Reencodes images as jpegs. (This behaviour should not be removed without understanding and consideration of the security aspect.)
Stores images to Azure Blob Storage. (Or elsewhere with your own implementation of IImageStore.)

Processing

It uses Magick.Net for processing, which is a .net wrapper for ImageMagick. The quality of processed images is very good.

Set-up

It is set up to use an Azure blob store for the images and SQL server for image information. You can change it to use different stores by using a new implementation of IImageStorageService or IInfoStorageService respectively.

The following packages are available on nuget to facilitate client development:

ExdTech.ImageServer.Common has definitions for the DTOs and the interfaces.
ExdTech.ImageServer.Persistence.ImageInfo has an EF model for the image info data store and an implementation of a data access service to access it.

Configuration

Configure appsettings.json. You must configure an image store and an info store for it to work.

  // Binds to ExdTech.ImageServer.Contract.ImageProcessingOptions.
  "ImageProcessingConfig": {
    "MaxWidthInPixels": 1080,   // Images are scaled down if this is exceeded. 
    "MaxHeightInPixels": 1080,  // Images are scaled down if this is exceeded.
    "MaxFileSizeNotCompressedInBytes": 200000,  // Images are compressed if this is exceeded.
    "MaxFileSizeAcceptedInBytes": 5000000,      // Images are rejected if this is exceeded.
    "CompressionQualityPercentage": 80          // Jpg compression quality to use if compressing.
  },

  "ImageStoreConnectionString": "<Connection string>",
  "ContainerClient": "<Container>", // Container must already exist

Storage

By default it uses Azure Blob Storage. You can configure this by setting "ImageStoreConnectionString" and "ContainerClient" configuration values. Alternatively you can replace it by implementing the IImageStorageService interface.

Authentication/Authorization

It uses Azure AD B2C authentication for POSTs. You will probably want to remove or change this. It can be turned off by removing the Authorize(Policy = "access") attribute from the POST method in the API contrller.

API and Schema

It uses JSON. See the swagger documentation for the live version at https://images.exdpic.com/index.html.

/{id} GET

Get an object containing the info and the image serialized as a byte array

/images/{id} GET

Get the image file. /images/{id}.jpeg and /images/{id}.jpg will also work.

/info/{id} GET

Get the image info only.

/ POST

Send the image serialized as a byte array as well as information about the image.

Licence

MIT

peterdongan / exdtech.imageserver Goto Github PK