How to convert a color image into sepia image in C# using Visual Studio

C# Project

In this project we are learning to convert a color image into sepia image using C#

Requirement

For this project we will need Microsoft Visual Studio

Introduction

To convert a color image into sepia image we have to perform the following 3 steps for each pixel.

  1. Get the RGB value of the pixel.
  2. Calculate tr, tg and tb using the formula

    tr = 0.393R + 0.769G + 0.189B
    tg = 0.349R + 0.686G + 0.168B
    tb = 0.272R + 0.534G + 0.131B

    Take the integer value.

  3. Set the new RGB value of the pixel as per the following condition:

    If tr > 255 then r = 255 else r = tr
    If tg > 255 then g = 255 else g = tg
    If tb > 255 then b = 255 else b = tb

Example:

Consider a color pixel with the following values

A = 255

R = 100

G = 150

B = 200

Where A, R, G and B represents the Alpha, Red, Green and Blue value of the pixel.

Remember! ARGB will have an integer value in the range 0 to 255.

So, to convert the color pixel into sepia pixel we have to first calculate tr, tg and tb.

tr = 0.393(100) + 0.769(150) + 0.189(200)

tr = 192.45

tr = 192 (taking integer value)

Similarly,

tg = 0.349(100) + 0.686(150) + 0.168(200) = 171 (taking integer value)

and tb = 0.272(100) + 0.534(150) + 0.131(200) = 133 (taking integer value)

Now we will replace the value of R, G and B with the new value that we calculated for the pixel.

So, the new pixel value will be

A = 255

R = 192

G = 171

B = 133

Note! We don't have to change the alpha value because it only controls the transparency of the pixel.

Form1.cs


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Sepia
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //read image
            Bitmap bmp = new Bitmap("D:\\Image\\zeenat.jpg");

            //load original image in picturebox1
            pictureBox1.Image = Image.FromFile("D:\\Image\\zeenat.jpg");

            //get image dimension
            int width = bmp.Width;
            int height = bmp.Height;

            //color of pixel
            Color p;

            //sepia
            for (int y = 0; y < height; y++)
            {
                for (int x = 0; x < width; x++)
                {
                    //get pixel value
                    p = bmp.GetPixel(x, y);

                    //extract pixel component ARGB
                    int a = p.A;
                    int r = p.R;
                    int g = p.G;
                    int b = p.B;

                    //calculate temp value
                    int tr = (int)(0.393 * r + 0.769 * g + 0.189 * b);
                    int tg = (int)(0.349 * r + 0.686 * g + 0.168 * b);
                    int tb = (int)(0.272 * r + 0.534 * g + 0.131 * b);

                    //set new RGB value
                    if (tr > 255)
                    {
                        r = 255;
                    }
                    else
                    {
                        r = tr;
                    }

                    if (tg > 255)
                    {
                        g = 255;
                    }
                    else
                    {
                        g = tg;
                    }

                    if (tb > 255)
                    {
                        b = 255;
                    }
                    else
                    {
                        b = tb;
                    }

                    //set the new RGB value in image pixel
                    bmp.SetPixel(x, y, Color.FromArgb(a, r, g, b));
                }
            }

            //load sepia image in picturebox2
            pictureBox2.Image = bmp;

            //save (write) sepia image
            bmp.Save("D:\\Image\\Sepia.png");
        }
    }
}

Form1.Designer.cs


namespace Sepia
{
    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()
        {
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            this.pictureBox2 = new System.Windows.Forms.PictureBox();
            this.label1 = new System.Windows.Forms.Label();
            this.label2 = new System.Windows.Forms.Label();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox2)).BeginInit();
            this.SuspendLayout();
            // 
            // pictureBox1
            // 
            this.pictureBox1.Location = new System.Drawing.Point(12, 12);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(328, 368);
            this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
            this.pictureBox1.TabIndex = 0;
            this.pictureBox1.TabStop = false;
            // 
            // pictureBox2
            // 
            this.pictureBox2.Location = new System.Drawing.Point(363, 12);
            this.pictureBox2.Name = "pictureBox2";
            this.pictureBox2.Size = new System.Drawing.Size(328, 368);
            this.pictureBox2.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
            this.pictureBox2.TabIndex = 1;
            this.pictureBox2.TabStop = false;
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.Font = new System.Drawing.Font("Microsoft Sans Serif", 14.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.label1.Location = new System.Drawing.Point(112, 383);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(75, 24);
            this.label1.TabIndex = 2;
            this.label1.Text = "Original";
            // 
            // label2
            // 
            this.label2.AutoSize = true;
            this.label2.Font = new System.Drawing.Font("Microsoft Sans Serif", 14.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.label2.Location = new System.Drawing.Point(499, 383);
            this.label2.Name = "label2";
            this.label2.Size = new System.Drawing.Size(58, 24);
            this.label2.TabIndex = 3;
            this.label2.Text = "Sepia";
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(703, 414);
            this.Controls.Add(this.label2);
            this.Controls.Add(this.label1);
            this.Controls.Add(this.pictureBox2);
            this.Controls.Add(this.pictureBox1);
            this.Name = "Form1";
            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
            this.Text = "Sepia";
            this.Load += new System.EventHandler(this.Form1_Load);
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox2)).EndInit();
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.PictureBox pictureBox1;
        private System.Windows.Forms.PictureBox pictureBox2;
        private System.Windows.Forms.Label label1;
        private System.Windows.Forms.Label label2;
    }
}