c# - 将图片框中的图像更改为棕褐色

Question

我有一个图片框，想将图像颜色更改为棕褐色 我知道到目前为止该怎么做，将其设置为灰度然后对其进行过滤，但最后一部分是我的垮台有人可以帮助我将其设置为棕褐色吗根据我提供的评论建议我应该做什么，非常感谢

Answer 1

您的代码可以归结为:

    private void button1_Click(object sender, EventArgs e)
    {
        Bitmap sepiaEffect = (Bitmap)pictureBox.Image.Clone();
        for (int yCoordinate = 0; yCoordinate < sepiaEffect.Height; yCoordinate++)
        {
            for (int xCoordinate = 0; xCoordinate < sepiaEffect.Width; xCoordinate++)
            {
                Color color = sepiaEffect.GetPixel(xCoordinate, yCoordinate);
                double grayColor = ((double)(color.R + color.G + color.B)) / 3.0d;
                Color sepia = Color.FromArgb((byte)grayColor, (byte)(grayColor * 0.95), (byte)(grayColor * 0.82));
                sepiaEffect.SetPixel(xCoordinate, yCoordinate, sepia);
            }
        }
        pictureBox.Image = sepiaEffect;
    }

然而，这是一组相当慢的嵌套循环。一种更快的方法是创建一个 ColorMatrix 来表示如何转换颜色，然后使用 ColorMatrix 通过 ImageAttributes 将图像重新绘制为新的位图:

    private void button2_Click(object sender, EventArgs e)
    {
        float[][] sepiaValues = {
            new float[]{.393f, .349f, .272f, 0, 0},
            new float[]{.769f, .686f, .534f, 0, 0},
            new float[]{.189f, .168f, .131f, 0, 0},
            new float[]{0, 0, 0, 1, 0},
            new float[]{0, 0, 0, 0, 1}};
        System.Drawing.Imaging.ColorMatrix sepiaMatrix = new System.Drawing.Imaging.ColorMatrix(sepiaValues);
        System.Drawing.Imaging.ImageAttributes IA = new System.Drawing.Imaging.ImageAttributes();
        IA.SetColorMatrix(sepiaMatrix);
        Bitmap sepiaEffect = (Bitmap)pictureBox.Image.Clone();
        using (Graphics G = Graphics.FromImage(sepiaEffect))
        {
            G.DrawImage(pictureBox.Image, new Rectangle(0, 0, sepiaEffect.Width, sepiaEffect.Height), 0, 0, sepiaEffect.Width, sepiaEffect.Height, GraphicsUnit.Pixel, IA);
        } 
        pictureBox.Image = sepiaEffect;
    }

我从 this 得到棕褐色调值文章。