EmguCV-第12讲-图像的几何变换（缩放、平移、旋转、转置、镜像和重映射）

1 图像缩放

补充：超分辨率缩放可实现图像不失真

2 图像平移

3 图像旋转

4 转置和镜像

5 重映射

6 代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Emgu.CV;
using Emgu.CV.Structure;
using Emgu.CV.CvEnum;
using Emgu.Util;
using System.Drawing;

namespace Lesson12
{
    class Program
    {
        static void Main(string[] args)
        {
            #region  图像缩放---Resize
            //Mat srcImg = CvInvoke.Imread("opencv.jpg");
            //CvInvoke.Imshow("src", srcImg);
            /////超分辨率,可实现无失真缩放
            //Mat dstImg = new Mat();
            //CvInvoke.Resize(srcImg, dstImg, new Size(600, 400));
            ////CvInvoke.Resize(srcImg, dstImg, new Size(), 0.5, 0.5);

            //CvInvoke.Imshow("dst", dstImg);
            //CvInvoke.WaitKey(0);
            #endregion

            #region 图像平移
            //Image<Bgr, Byte> srcImg = new Image<Bgr, Byte>("1.jpg");
            //CvInvoke.Imshow("src", srcImg);
            //int xOffset = 100, yOffset = 100;
            ////不改变图像大小，信息会丢失)
            ////int dstRows = srcImg.Rows;
            ////int dstCols = srcImg.Cols;

            ////会改变图像大小，信息不丢失)
            //int dstRows = srcImg.Rows + Math.Abs(yOffset);
            //int dstCols = srcImg.Cols + Math.Abs(xOffset);

            //Image<Bgr, Byte> dstImg = new Image<Bgr, Byte>(dstCols, dstRows);
            //ImgTranslate(srcImg, dstImg, xOffset, yOffset);

            //CvInvoke.Imshow("dst", dstImg);
            //CvInvoke.WaitKey(0);
            #endregion

            #region 图像旋转
            //Mat srcImg = CvInvoke.Imread("1.jpg");
            //PointF center = new PointF(srcImg.Cols / 2, srcImg.Rows / 2);
            //double angle = 45;
            //double scale = 1;

            //Mat rotateMat = new Mat();
            //CvInvoke.GetRotationMatrix2D(center, angle, scale, rotateMat);//获取旋转矩阵

            //Mat dstImg = new Mat();
            //CvInvoke.WarpAffine(srcImg, dstImg, rotateMat, new Size(srcImg.Cols, srcImg.Rows));//进行仿射变换

            //CvInvoke.Imshow("dst", dstImg);
            //CvInvoke.WaitKey(0);
            #endregion

            #region 转置镜像
            Mat srcImg = CvInvoke.Imread("lena.jpg");
            CvInvoke.Imshow("src", srcImg);

            Mat dstImg = new Mat();
            //CvInvoke.Flip(srcImg, dstImg, FlipType.None); //X
            CvInvoke.Flip(srcImg, dstImg, FlipType.Horizontal); //Y
            //CvInvoke.Flip(srcImg, dstImg, FlipType.Vertical); //X
            CvInvoke.Transpose(dstImg, dstImg); //行列相反

            CvInvoke.Imshow("dst", dstImg);
            CvInvoke.WaitKey(0);

            #endregion

            #region 重映射
            //Image<Bgr, Byte> srcImg = new Image<Bgr, Byte>("lena.jpg");
            //CvInvoke.Imshow("src", srcImg);

            //Image<Gray, Single> xMatImg = new Image<Gray, Single>(srcImg.Cols, srcImg.Rows);
            //Image<Gray, Single> yMatImg = new Image<Gray, Single>(srcImg.Cols, srcImg.Rows);

            //for (int i = 0; i < srcImg.Rows; i++)
            //{
            //    for (int j = 0; j < srcImg.Cols; j++)
            //    {
            //        xMatImg[i, j] = new Gray(j);
            //        yMatImg[i, j] = new Gray(i + 5 * Math.Sin(j / 10.0));
            //    }
            //}

            //Mat dstImg = new Mat();
            //CvInvoke.Remap(srcImg, dstImg, xMatImg, yMatImg, Inter.Area);

            //CvInvoke.Imshow("dst", dstImg);
            //CvInvoke.WaitKey(0);
            #endregion

        }



        #region 图像平移实现函数
        public static void ImgTranslate(Image<Bgr, Byte> srcImg, Image<Bgr, Byte> dstImg, int xOffset, int yOffset)
        {
            for (int i = 0; i < srcImg.Rows; i++)
            {
                for (int j = 0; j < srcImg.Cols; j++)
                {
                    int x = j + xOffset;
                    int y = i + yOffset;
                    if (x >= 0 && x < dstImg.Cols && y >= 0 && y < dstImg.Rows)
                        dstImg[y, x] = srcImg[i, j];
                }
            }
        }
        #endregion
    }

}