实现正方形图片的dct，即方阵dct的opencv代码

#include<iostream>
#include<fstream>
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>

using namespace std;
using namespace cv;
const double pi = 3.141592;
void initDctMat(Mat &A)  //计算8x8块的离散余弦变换系数
{
	for (int i = 0; i < A.cols; ++i)
		for (int j = 0; j <A.rows; ++j)
		{
			float a;
			if (i == 0)
				a = sqrt(1.0 / A.rows);//--------
			else
				a = sqrt(2.0 / A.rows);
			A.ptr<float>(i)[j] = a*cos((j + 0.5)*pi*i / A.rows);
		}
}
//dct变换
void myDct(Mat &image, const Mat &A)
{
	image(Range(0, image.rows), Range(0, image.cols)) = A * image(Range(0, image.rows), Range(0, image.cols)) *A.t();//range函数是什么意思
}
int main()
{
	//读取图像，图像为灰度图，单通道
	Mat image = imread("pic.png", CV_LOAD_IMAGE_GRAYSCALE);
	Mat fimage;
	Mat A(Size(image.rows, image.cols), CV_32FC1);// 离散余弦系数矩阵---------定义矩阵的大小以及cv——32FC1？？
	//显示原图
	if (!image.empty())
		imshow("image", image);
	//计算A系数
	initDctMat(A);
	//转换成浮点数矩阵，进行dct变换
	image.convertTo(fimage, CV_32FC1);//将图片转化成浮点数矩阵，然后进行dct的变换----------
	myDct(fimage, A);//参数为图片，离散余弦系数矩阵，mask量化，该函数的作用是进行dct变换，在函数中fimage当做x
	imshow("压缩图", fimage);//dct变换后的图片
	imshow("还原图", image);
	waitKey(0);
	return 0;
}

 

 

 

G

M

T

 

 

Detect languageAfrikaansAlbanianAmharicArabicArmenianAzerbaijaniBasqueBelarusianBengaliBosnianBulgarianCatalanCebuanoChichewaChinese (Simplified)Chinese (Traditional)CorsicanCroatianCzechDanishDutchEnglishEsperantoEstonianFilipinoFinnishFrenchFrisianGalicianGeorgianGermanGreekGujaratiHaitian CreoleHausaHawaiianHebrewHindiHmongHungarianIcelandicIgboIndonesianIrishItalianJapaneseJavaneseKannadaKazakhKhmerKoreanKurdishKyrgyzLaoLatinLatvianLithuanianLuxembourgishMacedonianMalagasyMalayMalayalamMalteseMaoriMarathiMongolianMyanmar (Burmese)NepaliNorwegianPashtoPersianPolishPortuguesePunjabiRomanianRussianSamoanScots GaelicSerbianSesothoShonaSindhiSinhalaSlovakSlovenianSomaliSpanishSundaneseSwahiliSwedishTajikTamilTeluguThaiTurkishUkrainianUrduUzbekVietnameseWelshXhosaYiddishYorubaZulu

AfrikaansAlbanianAmharicArabicArmenianAzerbaijaniBasqueBelarusianBengaliBosnianBulgarianCatalanCebuanoChichewaChinese (Simplified)Chinese (Traditional)CorsicanCroatianCzechDanishDutchEnglishEsperantoEstonianFilipinoFinnishFrenchFrisianGalicianGeorgianGermanGreekGujaratiHaitian CreoleHausaHawaiianHebrewHindiHmongHungarianIcelandicIgboIndonesianIrishItalianJapaneseJavaneseKannadaKazakhKhmerKoreanKurdishKyrgyzLaoLatinLatvianLithuanianLuxembourgishMacedonianMalagasyMalayMalayalamMalteseMaoriMarathiMongolianMyanmar (Burmese)NepaliNorwegianPashtoPersianPolishPortuguesePunjabiRomanianRussianSamoanScots GaelicSerbianSesothoShonaSindhiSinhalaSlovakSlovenianSomaliSpanishSundaneseSwahiliSwedishTajikTamilTeluguThaiTurkishUkrainianUrduUzbekVietnameseWelshXhosaYiddishYorubaZulu

 

 

 

Text-to-speech function is limited to 200 characters

 

Options : History : Feedback : Donate

Close