How To Extract Images present with text content in Video using OpenCVSharp?

Question

I am trying to extract images out of video using opencvsharp and I need to create a pdf and store only those images in pdf where there is a text content in the image.

I have written following code till now, Please help or advice further on how to identify and extract frames only where there is a text in image.

Thanks in advance!

using OpenCvSharp;
using System;
using System.IO;

namespace VideoToImage
{
    internal class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Begin video to image program..");   
            var videoFile = "C:\\Users\\sinequa\\Downloads\\cloud-computing-in-6-minutes-what-is-cloud-computing-cloud-computing-explained-simplilearn.mp4"; // Specify path to MP4 video file.
            var outputPath = "output_images"; // Path is relative to working directory of the app
            System.IO.Directory.CreateDirectory(outputPath);

            var capture = new VideoCapture(videoFile);
            var image = new Mat();
            int i = 0;
            
            Console.WriteLine("Begin extracting frames from video file..");
            bool capOpen=capture.Open(videoFile);
            bool isCapOpen=capture.IsOpened();
            Console.WriteLine(isCapOpen);
            int counter=0;
            //Adding counter to only save 5th frame
            while (capture.IsOpened())
            {
                // Read next frame in video file
                Console.WriteLine("capture is open");
                counter+=1;
                capture.Read(image);
                if (image.Empty())
                {
                    break;
                }
                if(counter == 5){
                    // Save image to disk.
                    Cv2.ImWrite(String.Format("output_images\\frame{0}.png", i), image);
                    Console.WriteLine(String.Format("Succesfully saved frame {0} to disk.", i));
                    counter=0;
                }
                

                i++;
            }

            Console.WriteLine(String.Format("Finished, check output at: {0}.", Path.GetFullPath(outputPath)));
        }
    }
}