How to do it...

1. Create a new Azure Function by choosing the Samples in the Scenario drop-down as shown in the following screenshot:

1. Select the ImageResizer-CSharp template as shown in the preceding screenshot.
2. Once you have selected the template, the portal prompts you to choose the following parameters:
   • Name your Function: Provide a meaningful name. For this example, I have provided CropProfilePictures.
   • Azure Blob Storage trigger (image):
     • Path: Provide the path of the container (in our case userprofileimagecontainer) which contains all the blobs that are created by the Queue trigger. CreateProfilePictures in the previous recipe
     • Storage account connection: Select the connection string of the storage account where the container and Blobs are stored

1. • Azure Blob Storage output (imageMedium):
     • Path: Please provide the name of the container where the resized images of size medium 200*200 are to be stored. In this case, userprofileimagecontainer-md.
     • Storage account connection: Select the connection string of the storage account where the Blobs are stored.
   • Azure Blob Storage output (imageSmall):
     • Path: Please provide the name of the container where the resized images of size small 100*100 are to be stored. In this case, userprofileimagecontainer-sm.
     • Storage account connection: Select the connection string of the storage account where the Blobs are stored.

1. Review all the details and click on Create as shown in the following screenshot:

1. Fortunately, the ImageResizer Azure Function template provides most of the necessary code for our requirement of resizing the image. I just made a few minor tweaks. Replace the default code with the following code and the code should be self-explanatory:

        using ImageResizer;
 
        public static void Run(
          Stream image, Stream imageSmall, Stream imageMedium) 
          {
            var imageBuilder = ImageResizer.ImageBuilder.Current;
            var size = imageDimensionsTable[ImageSize.Small];
            imageBuilder.Build(image, imageSmall, new ResizeSettings
             (size.Item1, size.Item2, FitMode.Max, null), false);
            image.Position = 0;
            size = imageDimensionsTable[ImageSize.Medium];
            imageBuilder.Build(image, imageMedium, new ResizeSettings
             (size.Item1, size.Item2, FitMode.Max, null), false);
          }

        public enum ImageSize
        {
            Small, Medium
        }

        private static Dictionary<ImageSize, Tuple<int, int>> 
         imageDimensionsTable = new Dictionary<ImageSize, Tuple<int,         
         int>>()
        {
            { ImageSize.Small, Tuple.Create(100, 100) },
            { ImageSize.Medium, Tuple.Create(200, 200) }
        };

1. Let's run a test on the RegisterUser function by submitting a sample request with firstname, lastname, and a ProfilePicUrl. I have used the same inputs that we have used in our previous recipes.

1. In the Azure Storage Explorer, I can see two new Blob containers userprofileimagecontainer-md and userprofileimagecontainer-sm as shown in the following screenshot:

1. I can even view the corresponding cropped versions in each of those containers. Following are the three versions of the image that we have used as input: