c# - 自动为图像添加水印

Question

在寻找自动将水印添加到互联网上的图像的解决方案时，我在 stackoverflow 中找到了最佳解决方案。问题的链接是C# - 通过特殊方式为照片添加水印。我特别感谢 Alex Maslakov和adrift。

我通过一些修改实现了该解决方案，我想将水印放在图像的中心。我修改了adrift提供的解决方案如下

   private void button1_Click(object sender, EventArgs e)
    {
        using (Image image = Image.FromFile(@"C:\Users\Public\Pictures\Sample Pictures\Desert.jpg"))
        using (Image watermarkImage = Image.FromFile(@"C:\Users\Public\Pictures\Sample Pictures\watermark.png"))
        using (Graphics imageGraphics = Graphics.FromImage(image))
        using (Brush watermarkBrush = new TextureBrush(watermarkImage))
        {
            int x = (image.Width - watermarkImage.Width)/2;
            int y = (image.Height - watermarkImage.Height)/2;
            imageGraphics.FillRectangle(watermarkBrush, new Rectangle(new Point(x, y), watermarkImage.Size));
            image.Save(@"C:\Users\Public\Pictures\Sample Pictures\Desert_watermark.jpg");
        }

    }

但水印没有正确放置在图像的中心（见下图）。

请纠正我...

谢谢

Answer 1

最后我找到了我的问题的解决方案......

更正的代码答案如下

    private void button1_Click(object sender, EventArgs e)
    {
        using (Image image = Image.FromFile(@"C:\Users\Public\Pictures\Sample Pictures\Desert.jpg"))
        using (Image watermarkImage = Image.FromFile(@"C:\Users\Public\Pictures\Sample Pictures\watermark.png"))
        using (Graphics imageGraphics = Graphics.FromImage(image))
        using (TextureBrush watermarkBrush = new TextureBrush(watermarkImage))
        {
            int x = (image.Width / 2 - watermarkImage.Width / 2);
            int y = (image.Height / 2 - watermarkImage.Height / 2);
            watermarkBrush.TranslateTransform(x, y);
            imageGraphics.FillRectangle(watermarkBrush, new Rectangle(new Point(x, y), new Size(watermarkImage.Width+1, watermarkImage.Height)));
            image.Save(@"C:\Users\Public\Pictures\Sample Pictures\Desert_watermark.jpg");
        }

    }

感谢 Furqan Safdar 和 Abdias Software The link Problem in tiling image started at different height using TextureBrush in C#也帮助我解决了这个问题

谢谢大家

最终结果

Answer 2

顺便说一句，您的原始公式很好，

你确定两者的分辨率是一样的吗？将水印图像的 DPI 分辨率设置为等于图像：

watermarkImage.SetResolution(imageGraphics.DpiX, imageGraphics.DpiY);

（从我的头顶开始，但我认为属性名称是正确的）。

更新：

从图像更改为位图以便使用SetResolution()- 看看这个更改是否适合你 - 我已经改变了水印在图像上的绘制方式：

private void button1_Click(object sender, EventArgs e) {

    using (Bitmap image = Bitmap.FromFile("C:\Users\Public\Pictures\Sample Pictures\Desert.jpg"))
    using (Bitmap watermarkImage = Bitmap.FromFile("C:\Users\Public\Pictures\Sample Pictures\watermark.png"))
    using (Graphics imageGraphics = Graphics.FromImage(image))
    {
        watermarkImage.SetResolution(imageGraphics.DpiX, imageGraphics.DpiY);

        int x = ((image.Width - watermarkImage.Width) / 2);
        int y = ((image.Height - watermarkImage.Height) / 2);

        imageGraphics.DrawImage(watermarkImage, x, y, watermarkImage.Width, watermarkImage.Height);

        image.Save("C:\Users\Public\Pictures\Sample Pictures\Desert_watermark.jpg");
    }
}

Answer 3

试试这个代码中心对齐：

int x = (image.Width / 2 - watermarkImage.Width / 2);
int y = (image.Height / 2 - watermarkImage.Height / 2);

Answer 4

工作样本：

public static Bitmap WatermarkImage(Bitmap image, Bitmap watermark)
{
    using (Graphics imageGraphics = Graphics.FromImage(image))
    {
        watermark.SetResolution(imageGraphics.DpiX, imageGraphics.DpiY);

        int x = (image.Width - watermark.Width) / 2;
        int y = (image.Height - watermark.Height) / 2;

        imageGraphics.DrawImage(watermark, x, y, watermark.Width, watermark.Height);
    }

    return image;
}

用法：

Bitmap watermark = new Bitmap(@"c:/watermark.png");
Bitmap bitmap = new Bitmap(@"c:/image.png");
bitmap = WatermarkImage(bitmap, watermark);
bitmap.Save(@"C:/watermarkedImage.png");