How to search for words in image and highlight them?

Scripting
1

This is what I am trying to achieve:

How do I make it so that when I hover over a word with camera that matches keyword it highlights the keyword?

using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;
using System.IO;

public class imagetotext : MonoBehaviour
{

private string keyWord = string.Empty;
WebCamTexture webcamTexture = new WebCamTexture(); // Plane gets camera texture

void Start()
{


    Renderer renderer = plane.GetComponent<Renderer>();
    renderer.material.mainTexture = webcamTexture;

    plane.SetActive(true);

}
void OnGUI()
{
keyWord = GUI.TextField(new Rect(0, 0, 300, 45), keyWord, 15); //keyword
}
2

Vuforia has a text recognition part of their software that you can look into. Otherwise, to design this yourself is probably going to be really tough to do.