C#根据原始图像改变水印图像大小

Question

我在上传之前给我的图像做水印。我面临的问题是如果图像很小，水印看起来就很大.我想根据原始图像改变水印图像的大小。

例如:水印图像应该是原始图像的30%。我在c#上这样做：

imageGraphics.FillRectangle(watermarkBrush，新矩形(新点(x，y)，新大小(watermarkImage.Width+ 1，watermarkImage.Height))；

我该怎么做才能先得到图像大小，然后相应地改变水印图像大小？

Answer 1

好吧，then...something喜欢：

Bitmap yourImage = ...;
Bitmap yourWatermark = ...;

int newWaterWidth = (int)((float)yourImage.Width * .3);
int newWaterHeight = (int)((float)yourImage.Height* .3);


using(Bitmap resizedWaterm = new Bitmap(newWaterWidth, newWaterHeight))
using(Graphics g = Graphics.FromImage((Image)resizedWaterm))
{
  g.InterpolationMode = InterpolationMode.HighQualityBicubic;
  g.DrawImage(yourWatermark, 0, 0, newWaterWidth , newWaterHeight );
}

int x = ..., y = ...;
using(Graphics g2 = Graphics.FromImage((Image)resizedWaterm))
{
  g2.FillRectangle(watermarkBrush, new Rectangle(new Point(x, y), new Size(watermarkImage.Width + 1, watermarkImage.Height)));
}

(没有测试，您还需要在.(圆点)

调整大小的代码：Resizing an Image without losing any quality

希望这能有所帮助！

Answer 2

NReco.VideoConverter.FFMpegConverter ffMpeg =新NReco.VideoConverter.FFMpegConverter()；

            string pathToVideoFile = "D:\\Projects\\Project\\Db_Script\\TAR_Dummy\\TAR_Dummy\\Videos\\"+postedFile.FileName;
            string imagePath = "D:\\Watermarks\\30.png";
            string Id = Guid.NewGuid().ToString();

            //Convert videos from one format to another
            ffMpeg.ConvertMedia(pathToVideoFile, "D:\\Watermarks\\"+Id+".flv", Format.flv);

            //Add Aatermark to videos
            ffMpeg.Invoke("-i "+pathToVideoFile+ " -i "+ imagePath + " -filter_complex \"overlay=10:10\" D:\\Watermarks\\Images\\" + Id+".mp4");

            //Get video thumbnail
            ffMpeg.GetVideoThumbnail(pathToVideoFile, "D:\\Watermarks\\Images\\" + Id.Substring(Id.Length-5)+".jpg");