OZEKI OZEKI Camera SDK
Build Webcam and IP camera solutions efficiently in C#.Net

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Download the SDK
Copy the C# code example into Visual Studio
Build your IP Camera project

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Did you know, that this SDK was used to build Ozeki Camera Recorder?

If you don't want to write code, it could be just what you need. Download it now from the follolwing page: Download Ozeki Camera Recorder.

Ozeki Camera SDK

Channel filtering | Gamma correction

Contrast Correction

Contrast means the proportion between the light and dark parts of a picture. By using this you will be able to give your image more contrast and make it displaying the curves and shapes more effectively. In this tutorial you will find a detailed example of creating a contrast correction filter using Ozeki Camera SDK. With this filter, we are able to set an optional value of the contrast of an image.

Important: you should study this article in order to find out how to setup your Windows Forms Application correctly.

Properties

Factor: Integer type value which we use to set the value of the contrast which must be between -127 and 127. If you choose a low amount, the effect makes the difference smaller between the dark and light parts and the image will become more pale. If you choose a bigger value, the effect makes the difference bigger and you will see the object boundries a lot more sharper.

before contrast correction — Figure 1 - Original image

after contrast correction — Figure 2 - Modified image with contrast filter

Windows Form

Windows forms version

MainForm.cs

using System;
using System.Windows.Forms;
using Ozeki.Camera;
using Ozeki.Media;

namespace ImageManipulation_WF
{
    public partial class MainForm : Form
    {
        private ICamera _camera;
        private DrawingImageProvider _imageProvider;
        private MediaConnector _connector;

        #region Initialize manipulation and filter
        private ImageManipulation _manipulation;
        private OzContrastCorrection _filter;
        #endregion

        public MainForm()
        {
            InitializeComponent();

            _connector = new MediaConnector();
            _imageProvider = new DrawingImageProvider();
            // Create video viewer UI control

            // Bind the camera image to the UI control
            videoViewer.SetImageProvider(_imageProvider);

            _manipulation = new ImageManipulation();
            _manipulation.Start();

            _filter = new OzContrastCorrection();
        }

        private void btn_Connect_Click(object sender, EventArgs e)
        {
            _camera = new WebCamera();

            if (_camera == null) return;

            _connector.Connect(_camera.VideoChannel, _manipulation);
            _connector.Connect(_manipulation, _imageProvider);

            _camera.Start();
            videoViewer.Start();
        }

        private void btn_Add_Click(object sender, EventArgs e)
        {
            _manipulation.Add(_filter);
        }

        private void btn_Remove_Click(object sender, EventArgs e)
        {
            _manipulation.Remove(_filter);
        }

        private void factorTrack_Scroll(object sender, EventArgs e)
        {
            var trackBar = sender as TrackBar;
            if (trackBar != null)
            {
                var value = trackBar.Value;
                _filter.Factor = value;
                lb_Level.Text = @"Factor: " + value;
            }
        }
    }
}

Code 1 Contrast correction in C#

GUI

Windows forms version

MainForm.Designer.cs

			namespace ImageManipulation_WF
{
    partial class MainForm
    {
        /// 
        /// Required designer variable.
        /// 
        private System.ComponentModel.IContainer components = null;

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

        #region Windows Form Designer generated code

        /// 
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// 
        private void InitializeComponent()
        {
            this.videoViewer = new Ozeki.Media.VideoViewerWF();
            this.btn_Connect = new System.Windows.Forms.Button();
            this.btn_Remove = new System.Windows.Forms.Button();
            this.btn_Add = new System.Windows.Forms.Button();
            this.lb_Level = new System.Windows.Forms.Label();
            this.trackBar = new System.Windows.Forms.TrackBar();
            ((System.ComponentModel.ISupportInitialize)(this.trackBar)).BeginInit();
            this.SuspendLayout();
            // 
            // videoViewer
            // 
            this.videoViewer.BackColor = System.Drawing.Color.Black;
            this.videoViewer.FlipMode = Ozeki.Media.FlipMode.None;
            this.videoViewer.FrameStretch = Ozeki.Media.FrameStretch.Uniform;
            this.videoViewer.FullScreenEnabled = true;
            this.videoViewer.Location = new System.Drawing.Point(12, 57);
            this.videoViewer.Name = "videoViewer";
            this.videoViewer.RotateAngle = 0;
            this.videoViewer.Size = new System.Drawing.Size(471, 334);
            this.videoViewer.TabIndex = 0;
            this.videoViewer.Text = "videoViewerWF1";
            // 
            // btn_Connect
            // 
            this.btn_Connect.Location = new System.Drawing.Point(12, 12);
            this.btn_Connect.Name = "btn_Connect";
            this.btn_Connect.Size = new System.Drawing.Size(152, 26);
            this.btn_Connect.TabIndex = 14;
            this.btn_Connect.Text = "Connect to WebCamera";
            this.btn_Connect.UseVisualStyleBackColor = true;
            this.btn_Connect.Click += new System.EventHandler(this.btn_Connect_Click);
            // 
            // btn_Remove
            // 
            this.btn_Remove.Location = new System.Drawing.Point(104, 475);
            this.btn_Remove.Name = "btn_Remove";
            this.btn_Remove.Size = new System.Drawing.Size(75, 23);
            this.btn_Remove.TabIndex = 1;
            this.btn_Remove.Text = "Remove";
            this.btn_Remove.UseVisualStyleBackColor = true;
            this.btn_Remove.Click += new System.EventHandler(this.btn_Remove_Click);
            // 
            // btn_Add
            // 
            this.btn_Add.Location = new System.Drawing.Point(23, 475);
            this.btn_Add.Name = "btn_Add";
            this.btn_Add.Size = new System.Drawing.Size(75, 23);
            this.btn_Add.TabIndex = 0;
            this.btn_Add.Text = "Add";
            this.btn_Add.UseVisualStyleBackColor = true;
            this.btn_Add.Click += new System.EventHandler(this.btn_Add_Click);
            // 
            // lb_Level
            // 
            this.lb_Level.AutoSize = true;
            this.lb_Level.Location = new System.Drawing.Point(20, 423);
            this.lb_Level.Name = "lb_Level";
            this.lb_Level.Size = new System.Drawing.Size(40, 13);
            this.lb_Level.TabIndex = 15;
            this.lb_Level.Text = "Factor:";
            // 
            // trackBar
            // 
            this.trackBar.Location = new System.Drawing.Point(104, 423);
            this.trackBar.Maximum = 127;
            this.trackBar.Minimum = -127;
            this.trackBar.Name = "trackBar";
            this.trackBar.Size = new System.Drawing.Size(379, 45);
            this.trackBar.TabIndex = 16;
            this.trackBar.Scroll += new System.EventHandler(this.factorTrack_Scroll);
            // 
            // MainForm
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(498, 520);
            this.Controls.Add(this.trackBar);
            this.Controls.Add(this.lb_Level);
            this.Controls.Add(this.btn_Remove);
            this.Controls.Add(this.btn_Add);
            this.Controls.Add(this.btn_Connect);
            this.Controls.Add(this.videoViewer);
            this.Name = "MainForm";
            this.Text = "Contrast correction setting";
            ((System.ComponentModel.ISupportInitialize)(this.trackBar)).EndInit();
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private Ozeki.Media.VideoViewerWF videoViewer;
        private System.Windows.Forms.Button btn_Connect;
        private System.Windows.Forms.Button btn_Remove;
        private System.Windows.Forms.Button btn_Add;
        private System.Windows.Forms.Label lb_Level;
        private System.Windows.Forms.TrackBar trackBar;
    }
}

Code 2 Contrast correction GUI in C#

Conclusion

With the help of this lecture you can successfully implement contrast correction with your C# camera application using the Ozeki Camera SDK.

FAQ

Below you can find the answers for the most frequently asked questions related to this topic:

What kind of developer environment is needed?
- Microsoft Visual Studio 2010
- Microsoft .Net Framework 4.0
- Internet connection
How can I get the URL of the camera?

You can get the URL from the producer of the camera.
I have not managed to build the solution. How to solve it?
- Please set the Target framework property of the project to .NET 4.0.
- You should add the OzekiSDK.dll to the references of the solution.
- Please import the missing classes.

Channel filtering | Gamma correction

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Get started

Did you know?

Contrast Correction

Properties

Windows forms version

MainForm.cs

GUI

Windows forms version

MainForm.Designer.cs

Related Pages

Conclusion

FAQ