c# - 透视图-上传C#方法

Question

我目前正在我的 ASP.NET Web 应用程序中处理上传功能，我需要在保存图片之前对其进行透视。

前任。 http://i.stack.imgur.com/YAM2s.png

我知道我可以在我的前端使用 CSS3 和 jQuery 来做到这一点，但我希望它是上传时看起来像这样的实际图片。

我希望你们中的一些人可以帮助我使用 C# 方法在图片上传下执行此操作。

Answer 1

//Add new item:
public struct Vertex
{
   public double X, Y, Z;
   public Vertex(double x, double y, double z)
   {
      this.X = x;
      this.Y = y;
      this.Z = z;
   }
}
//In page's code add:
public PointF GetPerspectiveProjectionOf(double x, double y, double z)
{
   double size = 2.0 * z * Math.Tan(Math.PI / 4.0);
   return new PointF((float)(x / size + 0.5), (float)(1.0 - y / size - 0.5));
}
public Image Upload(Image image, double distance, double spinInDegrees, int widthOfNewImage, int heightOfNewImage)
{
   double spinInRadians = spinInDegrees * Math.PI / 180.0;
   var v1 = new Vertex((-image.Width / 2.0) * Math.Cos(spinInRadians), image.Height / 2.0, (-image.Width / 2.0) * Math.Sin(spinInRadians));
   var v2 = new Vertex(-v1.X, v1.Y, -v1.Z);
   var v3 = new Vertex(v2.X, -v2.Y, v2.Z);
   var v4 = new Vertex(v1.X, -v1.Y, v1.Z);
   v1.Z += distance;
   v2.Z += distance;
   v3.Z += distance;
   v4.Z += distance;
   if (v1.Z < 0.0 || v2.Z < 0.0 || v3.Z < 0.0 || v4.Z < 0.0)
   {
       throw new ArgumentException("You are heading too close to the spinned image! You should increase distance.", "distance");
   }
   Image img = new Bitmap(widthOfNewImage, heightOfNewImage);
   Graphics graphics = Graphics.FromImage(img);
   graphics.SmoothingMode = SmoothingMode.AntiAlias;
   SolidBrush sb = new SolidBrush(Color.Empty);
   Bitmap bitmap = (Bitmap)image;
   for (int y = 0; y < image.Height; y++)
   {
      for (int x = 0; x < image.Width; x++)
      {
          var x1 = v1.X + x * Math.Cos(spinInRadians);
          var z1 = v1.Z + x * Math.Sin(spinInRadians);
          var y1 = v1.Y - y;
          var x2 = v1.X + (x + 1) * Math.Cos(spinInRadians);
          var z2 = v1.Z + (x + 1) * Math.Sin(spinInRadians);
          var y2 = v1.Y - y - 1;
          var p1 = GetPerspectiveProjectionOf(x1, y1, z1);
          var p2 = GetPerspectiveProjectionOf(x2, y1, z2);
          var p3 = GetPerspectiveProjectionOf(x2, y2, z2);
          var p4 = GetPerspectiveProjectionOf(x1, y2, z1);
          p1.X *= widthOfNewImage;
          p1.Y *= heightOfNewImage;
          p2.X *= widthOfNewImage;
          p2.Y *= heightOfNewImage;
          p3.X *= widthOfNewImage;
          p3.Y *= heightOfNewImage;
          p4.X *= widthOfNewImage;
          p4.Y *= heightOfNewImage;
          sb.Color = bitmap.GetPixel(x, y);
          graphics.FillPolygon(sb, new PointF[] { p1, p2, p3, p4 });
      }
   }
   sb.Dispose();
   graphics.Dispose();
   return img;
}

确认您是：

using System.Drawing;
//AND
using Systen.Drawing.Drawing2D;

命名空间，当然您已经添加了对 System.Drawing 的引用。您可以使用此方法并给出任何距离和角度，直到您对结果感到满意为止。如有必要，您可以使用其他编辑器（如 Photoshop）来裁剪结果图像，然后您可以将其用于任何目的。在发布此答案之前，我在家里对其进行了测试，最后它对我来说非常有用。没有理由为什么它也不适合您。希望这有助于并符合您的要求。玩得开心！