Сохранение в формате jpg с минимальной потерей качества по сравнению в bmp.

public int i = 0; //счётчик цикла
 
private void timer1_Tick(object sender, EventArgs e)
{
            Size ScreenSize = Screen.PrimaryScreen.Bounds.Size;
            Bitmap image = new Bitmap(ScreenSize.Width, ScreenSize.Height);
            using (Graphics g = Graphics.FromImage(image))
            {
                g.CopyFromScreen(Point.Empty, Point.Empty, ScreenSize);
 
                image.Save(textBox1.Text + i + ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
            }
 
            i = i + 1;
}

private void VaryQualityLevel()
{
    // Get a bitmap.
    Bitmap bmp1 = new Bitmap(@"c:\TestPhoto.jpg");
    ImageCodecInfo jgpEncoder = GetEncoder(ImageFormat.Jpeg);
 
    // Create an Encoder object based on the GUID
    // for the Quality parameter category.
    System.Drawing.Imaging.Encoder myEncoder =
        System.Drawing.Imaging.Encoder.Quality;
 
    // Create an EncoderParameters object.
    // An EncoderParameters object has an array of EncoderParameter
    // objects. In this case, there is only one
    // EncoderParameter object in the array.
    EncoderParameters myEncoderParameters = new EncoderParameters(1);
 
    EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, 50L);
    myEncoderParameters.Param[0] = myEncoderParameter;
    bmp1.Save(@"c:\TestPhotoQualityFifty.jpg", jgpEncoder, myEncoderParameters);
 
    myEncoderParameter = new EncoderParameter(myEncoder, 100L);
    myEncoderParameters.Param[0] = myEncoderParameter;
    bmp1.Save(@"c:\TestPhotoQualityHundred.jpg", jgpEncoder, myEncoderParameters);
 
    // Save the bitmap as a JPG file with zero quality level compression.
    myEncoderParameter = new EncoderParameter(myEncoder, 0L);
    myEncoderParameters.Param[0] = myEncoderParameter;
    bmp1.Save(@"c:\TestPhotoQualityZero.jpg", jgpEncoder, myEncoderParameters);
 
}
 
 
...
 
 
private ImageCodecInfo GetEncoder(ImageFormat format)
{
 
    ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();
 
    foreach (ImageCodecInfo codec in codecs)
    {
        if (codec.FormatID == format.Guid)
        {
            return codec;
        }
    }
    return null;
}

        public int i = 0; //счётчик цикла
 
        private void timer1_Tick(object sender, EventArgs e)
        {
            Size ScreenSize = Screen.PrimaryScreen.Bounds.Size;
            Bitmap image = new Bitmap(ScreenSize.Width, ScreenSize.Height);
            using (Graphics g = Graphics.FromImage(image))
            {
                g.CopyFromScreen(Point.Empty, Point.Empty, ScreenSize);
            }
 
            //Get the list of available encoders
            ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
            //find the encoder with the image/jpeg mime-type
            ImageCodecInfo ici = null;
            foreach (ImageCodecInfo codec in codecs)
            {
                if (codec.MimeType == "image/jpeg")
                    ici = codec;
            }
            //Create a collection of encoder parameters (we only need one in the collection)
            EncoderParameters ep = new EncoderParameters();
 
            System.Drawing.Imaging.Encoder myEncoder = System.Drawing.Imaging.Encoder.Quality;
 
 
            for (int x = 25; x < 101; x += 25)
            {
                //Create an encoder parameter for quality with an appropriate level setting
                ep.Param[0] = new EncoderParameter(myEncoder, (long)x);
                //Save the image with a filename that indicates the compression quality used
                image.Save(textBox1.Text + i + ".jpg", ici, ep);
            }
 
            i = i + 1;
        }

using System.Drawing.Imaging;