input_tensor = new DenseTensor<float>(new[] { 1, 3, modelSize, modelSize });
for (int y = 0; y < resize_image.Height; y++)
 {
     for (int x = 0; x < resize_image.Width; x++)
     {
         input_tensor[0, 0, y, x] = resize_image.At<Vec3b>(y, x)[0];
         input_tensor[0, 1, y, x] = resize_image.At<Vec3b>(y, x)[1];
         input_tensor[0, 2, y, x] = resize_image.At<Vec3b>(y, x)[2];
     }
 }

if (pictureBox2.Image == null)
 {
     return;
 }
 Bitmap output = new Bitmap(pictureBox2.Image);
 var sdf = new SaveFileDialog();
 sdf.Title = "保存";
 sdf.Filter = "Images (*.jpg)|*.jpg|Images (*.png)|*.png|Images (*.bmp)|*.bmp|Images (*.emf)|*.emf|Images (*.exif)|*.exif|Images (*.gif)|*.gif|Images (*.ico)|*.ico|Images (*.tiff)|*.tiff|Images (*.wmf)|*.wmf";
 if (sdf.ShowDialog() == DialogResult.OK)
 {
     switch (sdf.FilterIndex)
     {
         case 1:
             {
                 output.Save(sdf.FileName, ImageFormat.Jpeg);
                 break;
             }
         case 2:
             {
                 output.Save(sdf.FileName, ImageFormat.Png);
                 break;
             }
         case 3:
             {
                 output.Save(sdf.FileName, ImageFormat.Bmp);
                 break;
             }
         case 4:
             {
                 output.Save(sdf.FileName, ImageFormat.Emf);
                 break;
             }
         case 5:
             {
                 output.Save(sdf.FileName, ImageFormat.Exif);
                 break;
             }
         case 6:
             {
                 output.Save(sdf.FileName, ImageFormat.Gif);
                 break;
             }
         case 7:
             {
                 output.Save(sdf.FileName, ImageFormat.Icon);
                 break;
             }
         case 8:
             {
                 output.Save(sdf.FileName, ImageFormat.Tiff);
                 break;
             }
         case 9:
             {
                 output.Save(sdf.FileName, ImageFormat.Wmf);
                 break;
             }
     }
     MessageBox.Show("保存成功，位置：" + sdf.FileName);    
 }