class ChangeContrastCommandExample
{
    public void ProcessImage()
    {
        // [ do not forget to set your image file path here! ]
        // open an existing image
        Vintasoft.Imaging.VintasoftImage image = new Vintasoft.Imaging.VintasoftImage("Flower.jpg");
            
        // create the command
        Vintasoft.Imaging.ImageProcessing.Color.ChangeContrastCommand command =
            new Vintasoft.Imaging.ImageProcessing.Color.ChangeContrastCommand(50);
        // set the region-of-interest to the left part of the image
        command.RegionOfInterest = new Vintasoft.Imaging.RegionOfInterest(0, 0, image.Width / 2, image.Height);
        // subscribe to progress event
        command.Progress +=
            new System.EventHandler<Vintasoft.Imaging.ImageProcessing.ImageProcessingProgressEventArgs>(command_Progress);
            
        try
        {
            // execute the command
            command.ExecuteInPlace(image);
        }
        catch (Vintasoft.Imaging.ImageProcessing.ImageProcessingException ex)
        {
            // show error message if problem occured
            System.Windows.Forms.MessageBox.Show(ex.Message);
            return;
        }
            
        // save the processed image to the new file
        image.Save("processed-image.tif");
    }
            
    void command_Progress(object sender, Vintasoft.Imaging.ImageProcessing.ImageProcessingProgressEventArgs e)
    {
        // update progress info using e.Progress property
        // ...
            
        // cancel execution of command using e.Cancel property if necessary
        // ...
    }
}