OpenCV 自带颜色表实现各种滤镜

一、知识点
1、void applyColorMap(InputArray src, OutputArray dst, int colormap);
  (1)、通过给定的颜色映射表，将灰度图像或伪彩色图像转换为全彩色图像。
  (2)、参数说明:
      src: 源图像，灰度或彩色，类型为CV_8UC1或CV_8UC3。 如果是CV_8UC3，则使用cv::COLOR_BGR2GRAY在内部生成CV_8UC1图像。
      dst: 给源图像做颜色映射后的结果图像。
      colormap: 颜色映射需要的enum类型，具体见(3)。
  (3)、
      enum ColormapTypes
      {
          COLORMAP_AUTUMN = 0, //!< 
          COLORMAP_BONE = 1, //!< 
          COLORMAP_JET = 2, //!< 
          COLORMAP_WINTER = 3, //!< 
          COLORMAP_RAINBOW = 4, //!< 
          COLORMAP_OCEAN = 5, //!< 
          COLORMAP_SUMMER = 6, //!< 
          COLORMAP_SPRING = 7, //!< 
          COLORMAP_COOL = 8, //!< 
          COLORMAP_HSV = 9, //!< 
          COLORMAP_PINK = 10, //!< 
          COLORMAP_HOT = 11, //!< 
          COLORMAP_PARULA = 12, //!< 
          COLORMAP_MAGMA = 13, //!< 
          COLORMAP_INFERNO = 14, //!< 
          COLORMAP_PLASMA = 15, //!< 
          COLORMAP_VIRIDIS = 16, //!< 
          COLORMAP_CIVIDIS = 17, //!< 
          COLORMAP_TWILIGHT = 18, //!< 
          COLORMAP_TWILIGHT_SHIFTED = 19, //!< 
          COLORMAP_TURBO = 20, //!< 
          COLORMAP_DEEPGREEN = 21  //!< 
      };
  (4)、此功能通常用于增强图像的可视化效果，特别是在处理诸如热图(heatmaps)等数据可视化时非常有用。

二、示例代码: 循环切换各种滤镜

#include <iostream>
#include <opencv2/opencv.hpp>void TestColorMap(cv::Mat & src)
{int i_color_map[] = {cv::COLORMAP_AUTUMN,cv::COLORMAP_BONE,cv::COLORMAP_JET,cv::COLORMAP_WINTER,cv::COLORMAP_RAINBOW,cv::COLORMAP_OCEAN,cv::COLORMAP_SUMMER,cv::COLORMAP_SPRING,cv::COLORMAP_COOL,cv::COLORMAP_HSV,cv::COLORMAP_PINK,cv::COLORMAP_HOT,cv::COLORMAP_PARULA,cv::COLORMAP_MAGMA,cv::COLORMAP_INFERNO,cv::COLORMAP_PLASMA,cv::COLORMAP_VIRIDIS,cv::COLORMAP_CIVIDIS,cv::COLORMAP_TWILIGHT,cv::COLORMAP_TWILIGHT_SHIFTED,cv::COLORMAP_TURBO,cv::COLORMAP_DEEPGREEN};cv::Mat dst;int index = 0;while (true){int c = cv::waitKey(1000);if (c == 27){break;}cv::applyColorMap(src, dst, i_color_map[index % 22]);cv::imshow("颜色风格", dst);index++;}
}int main()
{cv::Mat src = cv::imread("../images/8.png");if (src.empty()){std::cout << "load src image error..." << std::endl;return -1;}cv::imshow("原始图像", src);TestColorMap(src);return 0;
}