MetadataTree.cs

This code demonstrates how to store, modify and parse metadata in ImageViews. An ImageView is created and metadata are stored into it. Then the metadata are modified and parsed.

using IOLink;
using System;
using System.Runtime.Intrinsics;
 
namespace Examples
{
    public class MetadataTree
    {
 
        private static void AddMetadata(ImageView image)
        {
            // if given image does not have write capability,
            // metadata cannot be added
            if (image.Support(ImageCapability.WRITE) == false)
            {
                throw new ApplicationException("Image does not support write capability");
            }
 
 
            // nodes are created one by one
            MetadataNode root = MetadataNodeFactory.Create("root", null);
            MetadataNode name = MetadataNodeFactory.Create(
              "name", VariantDataValueFactory.Create("generated image for example"));
            MetadataNode author = MetadataNodeFactory.Create(
              "author", VariantDataValueFactory.Create("Arthur Conley"));
            MetadataNode creationDate = MetadataNodeFactory.Create(
              "creation_date", VariantDataValueFactory.Create("2024-08-23"));
 
            root.AddChild(name);
            root.AddChild(author);
            root.AddChild(creationDate);
 
            // you can also use the helper class to create the
            // the helper class is more convenient to create trees with complex hierarchies
            MetadataNodeHelper.CreatePath(
              root, "parameters/param1", VariantDataValueFactory.Create(42));
            MetadataNodeHelper.CreatePath(
              root, "parameters/param2", VariantDataValueFactory.Create(3.14));
            MetadataNodeHelper.CreatePath(
              root, "parameters/param3", VariantDataValueFactory.Create("Hello world!"));
 
            MetadataNodeHelper.CreatePath(
              root, "parameters/version", VariantDataValueFactory.Create(1));
 
            // assign the metadata tree to the image
            image.Metadata = root;
        }
 
        private static void IncrementVersionMetadata(ImageView image)
        {
            // if given image does not have write capability,
            // metadata cannot be modified
            if (!image.Support(ImageCapability.WRITE))
            {
                throw new ApplicationException("Image does not support write capability");
            }
 
            // get the metadata tree from the image
            ReadonlyMetadataNode root = image.Metadata;
 
            // get the version node
            ReadonlyMetadataNode version = MetadataNodeHelper.GetNode(root, "parameters/version");
 
            // increment the version number
            long versionNumber = VariantDataValueConverter.ToInt64(version.Value);
            // clone the tree for modification
            MetadataNode newRoot = root.Clone();
            MetadataNodeHelper.CreatePath(
              newRoot, "parameters/version", VariantDataValueFactory.Create(versionNumber + 1));
 
            // assign the new metadata tree to the image
            image.Metadata = newRoot;
        }
 
        static private void RecursiveDisplayMethod(ReadonlyMetadataNode node, int depth)
        {
            // display the node
            Console.Write(new string(' ', depth * 2));
            Console.Write(string.Format("{0} + :", node.Key));
 
            // if there is a value associated with the node,
            // display it
            if (node.Value != null)
                Console.Write(VariantDataValueConverter.ToString(node.Value));
            Console.WriteLine("");
 
            // display the children
            foreach (MetadataNode child in node)
            {
                RecursiveDisplayMethod(child, depth + 1);
            }
        }
 
        public static void Main(string[] args)
        {
            // create an ImageView in CPU memory
            var image = ImageViewFactory.Allocate(new VectorXu64(100, 200), DataTypeId.UINT8);
 
            // add metadata to the image
            AddMetadata(image);
 
            // display the metadata tree
            RecursiveDisplayMethod(image.Metadata, 0);
 
            // increment the version number in the metadata
            IncrementVersionMetadata(image);
 
            // display the metadata tree
            RecursiveDisplayMethod(image.Metadata, 0);
 
            Console.WriteLine("SUCCESS");
        }
    }
}