private void button8_Click(object sender, EventArgs e) //степень
        {
            if (!CheckSourceImage())
            {
                return;
            }
            var str = textBoxPower.Text.Split(' ');

            if (str.Length != 2)
            {
                MessageBox.Show("Для степени введены неверные значения");
                return;
            }
            double power;
            double coef;

            try
            {
                power = double.Parse(str[0]); coef = double.Parse(str[1]);
            }
            catch
            {
                MessageBox.Show("Неверный ввод");
                return;
            }
            editImage = checkBoxAnti.Checked ? LuminanceConversions.GetAntiPower(editImage, power, coef) :
                        LuminanceConversions.GetPowerImage(editImage, power, coef);
            pictureBoxImage.Image = editImage;
            editImage.Save(@"Power.jpg");
            if (editImage != null)
            {
                label5TypeImage.Text = "Степень";
            }
        }