OpenCv 009---色彩空间与色彩空间转换

1 前备知识

各颜色对应的范围

2 所用到的主要OpenCv API

/** @brief Converts an image from one color space to another.

@param src input image: 8-bit unsigned, 16-bit unsigned ( CV_16UC... ), or single-precision
floating-point.
@param dst output image of the same size and depth as src.
@param code color space conversion code (see #ColorConversionCodes).
@param dstCn number of channels in the destination image; if the parameter is 0, the number of the
channels is derived automatically from src and code.

@see @ref imgproc_color_conversions
*/

CV_EXPORTS_W void cvtColor( InputArray src, OutputArray dst, int code, int dstCn = 0 );

/** @brief Checks if array elements lie between the elements of two other arrays.

That is, dst (I) is set to 255 (all 1 -bits) if src (I) is within the
specified 1D, 2D, 3D, ... box and 0 otherwise.

When the lower and/or upper boundary parameters are scalars, the indexes
(I) at lowerb and upperb in the above formulas should be omitted.
@param src first input array.
@param lowerb inclusive lower boundary array or a scalar.
@param upperb inclusive upper boundary array or a scalar.
@param dst output array of the same size as src and CV_8U type.
*/

CV_EXPORTS_W void inRange(InputArray src, InputArray lowerb,
                          InputArray upperb, OutputArray dst);

/** @brief Blurs an image using the normalized box filter.

The function smooths an image using the kernel:

@param src input image; it can have any number of channels, which are processed independently, but
the depth should be CV_8U, CV_16U, CV_16S, CV_32F or CV_64F.
@param dst output image of the same size and type as src.
@param ksize blurring kernel size.
@param anchor anchor point; default value Point(-1,-1) means that the anchor is at the kernel
center.
@param borderType border mode used to extrapolate pixels outside of the image, see #BorderTypes
@sa boxFilter, bilateralFilter, GaussianBlur, medianBlur
*/

CV_EXPORTS_W void blur( InputArray src, OutputArray dst,
                        Size ksize, Point anchor = Point(-1,-1),
                        int borderType = BORDER_DEFAULT );

/** @brief Blurs an image using the median filter.

@note The median filter uses #BORDER_REPLICATE internally to cope with border pixels, see #BorderTypes

@param src input 1-, 3-, or 4-channel image; when ksize is 3 or 5, the image depth should be
CV_8U, CV_16U, or CV_32F, for larger aperture sizes, it can only be CV_8U.
@param dst destination array of the same size and type as src.
@param ksize aperture linear size; it must be odd and greater than 1, for example: 3, 5, 7 ...
@sa bilateralFilter, blur, boxFilter, GaussianBlur
*/

CV_EXPORTS_W void medianBlur( InputArray src, OutputArray dst, int ksize );

3 程序代码

#include "opencv2\opencv.hpp"
#include <iostream>

using namespace std;
using namespace cv;

int main(int argc, char**argv)
{
    Mat src = imread("G:\\CVworkstudy\\program_wwx\\研习社140课时\\ZhaiZhigang140\\lena.jpg");
    if (src.empty())
    {
        printf("Could not load image...\n");
        return -1;
    }

    //色彩空间转换
    Mat yuvImg, hsvImg, ycrcbImg;
    cvtColor(src, yuvImg, CV_BGR2YUV);
    cvtColor(src, hsvImg, CV_BGR2HSV);
    cvtColor(src, ycrcbImg, CV_BGR2YCrCb);
    //图像显示
    imshow("YUV", yuvImg);
    imshow("HSV", hsvImg);
    imshow("YCRCB", ycrcbImg);

    Mat getColorImg, getMask, getMask1;
    getColorImg = imread("G:\\CVworkstudy\\program_wwx\\研习社140课时\\ZhaiZhigang140\\myPhoto.jpg");
    //imshow("MyPhoto", getColorImg);
    cvtColor(getColorImg, getColorImg, CV_BGR2HSV);//颜色提取需要先转换为HSV颜色空间
    //That is, dst (I) is set to 255 (all 1 -bits) if src (I) is within the
    //specified 1D, 2D, 3D, ... box and 0 otherwise.
    inRange(getColorImg, Scalar(100, 43, 46), Scalar(124, 255, 255), getMask);//蓝色范围内的颜色转换为255，其他为0
    blur(getMask, getMask1, Size(5, 5));//均值滤波会使边缘变得模糊
    imshow("GetMask1", getMask1);
    medianBlur(getMask, getMask, 5);//中值滤波对边缘轮廓影响较小
    imshow("GetMask", getMask);

    waitKey(0);
    return 0;
}

4 运行结果

5 扩展及注意事项

NULL