C#.net : Lab + Otsu with EmguCV

using System;
using System.Windows.Forms;
using System.Drawing;
using Emgu.CV;
using Emgu.CV.Structure;
using Emgu.CV.CvEnum;
using Emgu.CV.Util;

namespace WinFormsApp2
{
    public partial class Form1 : Form
    {
        private PictureBox originalImageBox;
        private PictureBox processedImageBox;
        private Button loadButton;

        public Form1()
        {
            InitializeComponent();
            this.Text = "Image Processing with EmguCV";
            this.Size = new Size(1000, 600);

        }

        private void LoadButton_Click(object sender, EventArgs e)
        {
            using (OpenFileDialog openFileDialog = new OpenFileDialog())
            {
                openFileDialog.Filter = "Image Files|*.jpg;*.jpeg;*.png;*.bmp;*.tif";
                openFileDialog.Title = "Select an Image";

                if (openFileDialog.ShowDialog() == DialogResult.OK)
                {
                    try
                    {
                        // Load the original image
                        Mat originalImage = CvInvoke.Imread(openFileDialog.FileName, ImreadModes.Color);

                        // Display original image
                        originalImageBox.Image = originalImage.ToBitmap();

                        // Process the image
                        Mat processedImage = ProcessImage(originalImage);

                        // Display processed image
                        processedImageBox.Image = processedImage.ToBitmap();
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show($"Error processing image: {ex.Message}", "Error",
                            MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                }
            }
        }

        private Mat ProcessImage(Mat originalImage)
        {
            // Convert BGR to Lab color space
            Mat labImage = new Mat();
            CvInvoke.CvtColor(originalImage, labImage, ColorConversion.Bgr2Lab);

            // Split the Lab image into L, a, and b channels
            VectorOfMat labChannels = new VectorOfMat();
            CvInvoke.Split(labImage, labChannels);

            // Get the 'a' channel (index 1)
            Mat aChannel = labChannels[1];

            // Apply Otsu thresholding on the 'a' channel
            Mat binaryImage = new Mat();
            CvInvoke.Threshold(aChannel, binaryImage, 0, 255,
                ThresholdType.Binary | ThresholdType.Otsu);

            return binaryImage;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //filename = @"C:\Users\user1\Pictures\473323273_586319737608833_8471197295915664510_n\474496606_588482517392555_4021026081075372739_n.jpg";
        }
    }
}

- Form1.cs

namespace WinFormsApp2
{
    partial class Form1
    {
        /// <summary>
        ///  Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        ///  Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        ///  Required method for Designer support - do not modify
        ///  the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {

            // Original Image PictureBox
            originalImageBox = new PictureBox
            {
                Location = new Point(20, 20),
                Size = new Size(450, 450),
                SizeMode = PictureBoxSizeMode.Zoom,
                BorderStyle = BorderStyle.FixedSingle
            };

            // Processed Image PictureBox
            processedImageBox = new PictureBox
            {
                Location = new Point(500, 20),
                Size = new Size(450, 450),
                SizeMode = PictureBoxSizeMode.Zoom,
                BorderStyle = BorderStyle.FixedSingle
            };

            // Load Image Button
            loadButton = new Button
            {
                Text = "Load Image",
                Location = new Point(20, 490),
                Size = new Size(120, 40)
            };
            loadButton.Click += LoadButton_Click;

            // Add controls to form
            this.Controls.Add(originalImageBox);
            this.Controls.Add(processedImageBox);
            this.Controls.Add(loadButton);

            SuspendLayout();
            // 
            // Form1
            // 
            AutoScaleDimensions = new SizeF(9F, 20F);
            AutoScaleMode = AutoScaleMode.Font;
            ClientSize = new Size(800, 450);
            Name = "Form1";
            Text = "Form1";
            Load += Form1_Load;
            ResumeLayout(false);
        }

        #endregion
    }
}

- Designer.cs